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Loop-corrected Higgs Masses in the NMSSM with Inverse Seesaw Mechanism: In this study, we work in the framework of the Next-to-Minimal extension of
the Standard Model (NMSSM) extended by six singlet leptonic superfields.
Through the mixing with the three doublet leptonic superfields, the non-zero
tiny neutrino masses can be generated through the inverse seesaw mechanism.
While $R$-parity is conserved in this model lepton number is explicitly
violated. We quantify the impact of the extended neutrino sector on the NMSSM
Higgs sector by computing the complete one-loop corrections with full momentum
dependence to the Higgs boson masses in a mixed on-shell-$\overline{\mbox{DR}}$
renormalization scheme, with and without the inclusion of CP violation. The
results are consistently combined with the dominant two-loop corrections at
${\cal O}(\alpha_t(\alpha_s+\alpha_t))$ to improve the predictions for the
Higgs mixing and the loop-corrected masses. In our numerical study we include
the constraints from the Higgs data, the neutrino oscillation data, the charged
lepton flavor-violating decays $l_i \to l_j + \gamma$, and the new physics
constraints from the oblique parameters $S,T,U$. We present in this context the
one-loop decay width for $l_i \to l_j + \gamma$. The loop-corrected Higgs boson
masses are included in the Fortran code NMSSMCALC-nuSS. | hep |
Efficiency of swimming of micro-organism and singularity in shape space: Micro-organisms can be classified into three different types according to
their size. We study the efficiency of the swimming of micro-organism in two
dimensional fluid as a device for helping the explanation of this hierarchy in
the size. We show that the efficiency of flagellate becomes unboundedly large,
whereas that of ciliate has the upper bound. The unboundedness is related to
the curious feature of the shape space, that is, a singularity at the basic
shape of flagellate. | hep |
QED(1+1) on the Light Front and its implications for
semiphenomenological methods in QCD(3+1): A possibility of semiphenomenological description of vacuum effects in QCD
quantized on the Light Front (LF) is discussed. A modification of the canonical
LF Hamiltonian for QCD is proposed, basing on the detailed study of the exact
description of vacuum condensate in QED(1+1) that uses correct form of LF
Hamiltonian. | hep |
Form Factors for Semileptonic B -> pi and D -> pi Decays from the Omnes
Representation: We use the Omnes representation to obtain the q-squared dependence of the
form factors f+ and f0 for semileptonic H -> pi decays from the elastic pi H ->
pi H scattering amplitudes, where H denotes a B or D meson. The scattering
amplitudes used satisfy elastic unitarity and are calculated from two-particle
irreducible amplitudes obtained using tree-level heavy meson chiral
perturbation theory (HMChPT). The q-squared dependences for the form factors
agree with lattice QCD results when the HMChPT coupling constant, g, takes
values smaller than 0.32, and confirm the milder dependence of f0 on q-squared
found in sumrule calculations. | hep |
Fully-heavy hadronic molecules $B_c^{(*)+} B_c^{(*)-}$ bound by
fully-heavy mesons: A lot of exotic hadrons were reported in the past twenty years, which bring
us the renaissance of the hadron spectroscopy. Most of them can be understood
as hadronic molecules, whose interactions are mainly due to the exchange of
light mesons, and specifically, light vector mesons through the coupled-channel
unitary approach within the local hidden-gauge formalism. It is still
controversial whether the interaction arising from the exchange of heavy mesons
is capable of forming hadronic molecules. We apply the coupled-channel unitary
approach to study the fully-heavy $b \bar b c \bar c$ system, where the
exchanged mesons can only be the fully-heavy vector mesons $J/\psi$, $B_c^*$,
and $\Upsilon$. Especially, the $J/\psi$ meson is much lighter than the
$B_c^{(*)}$ mesons, so the present study can be taken as a general
investigation on the question whether a lower-mass fully-heavy meson is able to
bind two higher-mass fully-heavy hadrons. Our results suggest the existence of
the fully-heavy hadronic molecules $|B_c^{+} B_c^{-}; J^{PC}=0^{++} \rangle$,
$|B_c^{*+} B_c^{-} - c.c.; J^{PC}=1^{+-} \rangle$, and $|B_c^{*+} B_c^{*-};
J^{PC}=2^{++} \rangle$ as well as the possible existence of $|B_c^{*+} B_c^{-}
+ c.c.; J^{PC}=1^{++} \rangle$. These states are potentially to be observed in
the $\mu^+ \mu^- J/\psi$ and $\mu^+ \mu^- \Upsilon$ channels in future ATLAS,
CMS, and LHCb experiments. | hep |
Loop corrections to pion and kaon neutrinoproduction: In this paper we study the next-to-leading order corrections to deeply
virtual pion and kaon production in neutrino experiments. We estimate these
corrections in the kinematics of the Minerva experiment at FERMILAB, and find
that they are sizable and increase the leading order cross-section by up to a
factor of two. We provide a code, which can be used for the evaluation of the
cross-sections, taking into account these corrections and employing various GPD
models. | hep |
Deep Learning Symmetries and Their Lie Groups, Algebras, and Subalgebras
from First Principles: We design a deep-learning algorithm for the discovery and identification of
the continuous group of symmetries present in a labeled dataset. We use fully
connected neural networks to model the symmetry transformations and the
corresponding generators. We construct loss functions that ensure that the
applied transformations are symmetries and that the corresponding set of
generators forms a closed (sub)algebra. Our procedure is validated with several
examples illustrating different types of conserved quantities preserved by
symmetry. In the process of deriving the full set of symmetries, we analyze the
complete subgroup structure of the rotation groups $SO(2)$, $SO(3)$, and
$SO(4)$, and of the Lorentz group $SO(1,3)$. Other examples include squeeze
mapping, piecewise discontinuous labels, and $SO(10)$, demonstrating that our
method is completely general, with many possible applications in physics and
data science. Our study also opens the door for using a machine learning
approach in the mathematical study of Lie groups and their properties. | hep |
Particle dynamics near extreme Kerr throat and supersymmetry: The extreme Kerr throat solution is believed to be non-supersymmetric.
However, its isometry group SO(2,1) x U(1) matches precisely the bosonic
subgroup of N=2 superconformal group in one dimension. In this paper we
construct N=2 supersymmetric extension of a massive particle moving near the
horizon of the extreme Kerr black hole. Bosonic conserved charges are related
to Killing vectors in a conventional way. Geometric interpretation of
supersymmetry charges remains a challenge. | hep |
Absorption of Sub-MeV Fermionic Dark Matter by Electron Targets: We study a new class of signals where fermionic dark matter is absorbed by
bound electron targets. Fermionic absorption signals in direct detection and
neutrino experiments are sensitive to dark matter with sub-MeV mass, probing a
region of parameter space in which dark matter is otherwise challenging to
detect. We calculate the rate and energy deposition spectrum in xenon-based
detectors, making projections for current and future experiments. We present
two possible models that display fermionic absorption by electrons and study
the detection prospects in light of other constraints. | hep |
The Untwisted Stabilizer in Simple Current Extensions: A method is presented to compute the order of the untwisted stabilizer of a
simple current orbit, as well as some results about the properties of the
resolved fields in a simple current extension. | hep |
Noncyclic geometric phases and helicity transitions for neutrino
oscillations in a magnetic field: We show that neutrino spin and spin-flavor transitions involve nonvanishing
geometric phases. The geometric character of neutrino spin rotation is explored
by studying the neutrino spin trajectory in the projective Hilbert space
representation and its relation to the geometric phase. Analytical expressions
are derived for noncyclic geometric phases. Several calculations are performed
for different cases of rotating and nonrotating magnetic fields in the context
of solar neutrinos and neutrinos produced inside neutron stars. Also the
effects of adiabaticity, critical magnetic fields and cross boundary effects in
the case of neutrinos emanating out of neutron stars are examined. | hep |
The LHC potential of Vector-like quark doublets: The existence of new vector-like quarks is often predicted by models of new
physics beyond the Standard Model, and the development of discovery strategies
at colliders is the object of an intense effort from the high-energy community.
Our analysis aims at identifying the constraints on and peculiar signatures of
simplified scenarios containing \textit{two} vector-like quark doublets mixing
with \textit{any} of the SM quark generations. This scenario is a necessary
ingredient of a broad class of theoretically motivated constructions. We focus
on the two charge $2/3$ states $t_{1,2}^\prime$ that, due to their peculiar
mixing patterns, feature new production and decay modes that are not searched
for at the LHC: single production of the heavier state can dominate over the
light one, while pair production via electroweak interactions overcomes the QCD
one for masses at the TeV scale. | hep |
Light Nuclei from Lattice QCD: Spectrum, Structure and Reactions: Lattice Quantum Chromodynamics (LQCD) studies of light nuclei have entered an
era when first results on structure and reaction properties of light nuclei
have emerged in recent years, complementing existing results on their
lowest-lying spectra. Although in these preliminary studies the quark masses
are still set to larger than the physical values, a few results at the physical
point can still be deduced from simple extrapolations in the quark masses. The
progress paves the road towards obtaining several important quantities in
nuclear physics, such as nuclear forces and nuclear matrix elements relevant
for pp fusion, single and double-beta decay processes, neutrino-nucleus
scattering, searches for CP violation, nuclear response in direct dark-matter
detection experiments, as well as gluonic structure of nuclei for an
Electron-Ion Collider (EIC) program. Some of the recent developments, the
results obtained, and the outlook of the field will be briefly reviewed in this
talk, with a focus on results obtained by the Nuclear Physics From LQCD
(NPLQCD) collaboration. | hep |
The effective action of Double Field Theory: We perform a generalized Scherk-Schwarz dimensional reduction of Double Field
Theory on a twisted double torus. The four dimensional effective action is
shown to exactly reproduce the bosonic electric sector of gauged N = 4
supergravity. We present explicit expressions for the gaugings in terms of the
twists, and analyze the associated string backgrounds. This framework provides
a higher dimensional origin of the gaugings in terms of generalized fluxes. | hep |
Tau Neutrino Decays and Big Bang Nucleosynthesis: We investigate the non-radiative decay during nucleosynthesis of a massive
tau neutrino with mass 0.1 - 1 MeV into an electron neutrino and a scalar or
pseudoscalar particle, $\phi$. The full Boltzmann equation is used and shown to
give markedly different results than the usual non-relativistic formalism for
relativistic or semi-relativistic neutrino decays. Indeed, the region we
investigate is where the formalism that has previously been applied to solving
this problem is expected to break down. We also compare the nucleosynthesis
predictions from this scenario with results from the standard model and with
some of the available observational determinations of the primordial
abundances. It is found that for relativistic or semi-relativistic decays the
helium abundance can be significantly lowered without changing other light
element abundances. Since a problem with the standard model of Big Bang
nucleosynthesis is that helium appears to be overproduced, a decay of the type
we discuss can be a possible solution. | hep |
Heavy Quark Decays: The status of heavy-quark decays as of summer 1999 is reviewed. New
measurements of semileptonic B decays from LEP and from CLEO are reported and
the status of determining the CKM parameters |Vcb| and |Vub| is assessed. Rare
charmless hadronic B decays are reviewed, including the first observation of
B->pi pi from CLEO. First attempts to measure CP asymmetries in rare decays are
described. The implications of all of the data for our understanding of the
Standard Model are briefly assessed. | hep |
Probing Relativity using Space-Based Experiments: An overview of space tests searching for small deviations from special
relativity arising at the Planck scale is given. Potential high-sensitivity
space-based experiments include ones with atomic clocks, masers, and
electromagnetic cavities. We show that a significant portion of the coefficient
space in the Standard-Model Extension, a framework that covers the full
spectrum of possible effects, can be accessed using space tests. Some remarks
on Lorentz violation in the gravitational sector are also given. | hep |
Semi-perturbative unification with extra vector-like families: We make a comprehensive analysis of an extended supersymmetric model(ESSM)
obtained by adding a pair of vector-like families to the minimal supersymmetric
standard model and having specific forms of 5 x 5 fermion mass matrices. The
singlet Higgs couplings which link the ordinary to vector-like generations do
not have the renormalization effects of the gauge interactions and hence the
"quasi-infrared fixed point" near the scale of the top quark mass. The two-loop
Yukawa effects on gauge couplings lead to an unified coupling $\alpha_X$ around
0.2 with an unification scale M_X of 10^{16.9} GeV. Large Yukawa effects in the
high energy region arrest the growth of the QCD coupling near M_X making the
evolution flat. The renormalization effects of the vector-like generations on
soft mass parameters has important effects on the charge and color
breaking(CCB)minima. We will show that there exists parameter space where there
is no charge and color breaking. We will also demonstrate that there exists
minima of the Higgs potential which satisfies the mass of the Z boson but avoid
CCB. Upper limits on the mass of the lightest Higgs boson from the one-loop
effective scalar potential is obtained for sets of universal soft supersymmetry
breaking mass parameters. | hep |
Scalar sector of Supersymmetric ${SU}(3)_C\otimes {SU}(3)_L \otimes
{U}(1)_N$ Model with right-handed neutrinos: We investigate a scalar sector of the supersymmetric $ SU_C(3) \otimes
SU_L(3)\otimes U_N(1)$ model with right-handed neutrinos. The mass spectra are
derived. We show that only neutral Higgs sector with lepton number L=0 could
have a VEV. There is no mixing between scalars having L=0 and bilepton scalars
having L=2. There are six Goldstone bosons: two in neutral sector, three in
pseudo-scalar sector and one in charged scalar sector. For a given set of input
parameters (five from the $F$ terms and two from the soft term) all the scalar
sectors in this model contain the upper limit of 230 GeV to the mass of the
lightest scalar, which are in agreement with the lower limit of the SM Higgs
boson obtained by LEP. | hep |
Summing the Instantons in Half-Twisted Linear Sigma Models: We study half-twisted linear sigma models relevant to (0,2) compactifications
of the heterotic string. Focusing on theories with a (2,2) locus, we examine
the linear model parameter space and the dependence of genus zero half-twisted
correlators on these parameters. We show that in a class of theories the
correlators and parameters separate into A and B types, present techniques to
compute the dependence, and apply these to some examples. These results should
bear on the mathematics of (0,2) mirror symmetry and the physics of the moduli
space and Yukawa couplings in heterotic compactifications. | hep |
On the high-energy Elastic Scattering of hadrons at large t: The main contribution to hard elastic scattering comes from components of
wave functions of colliding hadrons that contain minimum number of partons. We
discuss this mechanism in regge and parton approaches and estimate the
probabilities that colliding hadrons are in such bare states. The behavior of
cross-sections in this regime at various energies can give nontrivial
information on high energy dynamics. | hep |
Oscillons in the presence of external potential: We discuss similarity between oscillons and oscillational mode in perturbed
$\phi^4$. For small depths of the perturbing potential it is difficult to
distinguish between oscillons and the mode in moderately long time evolution,
moreover one can transform one into the other by adiabatically switching on and
off the potential. Basins of attraction are presented in the parameter space
describing the potential and initial conditions. | hep |
Modularity of Schur index, modular differential equations, and
high-temperature asymptotics: In this paper we analytically explore the modularity of the flavored Schur
index of 4d $\mathcal{N} = 2$ SCFTs. We focus on the $A_1$ theories of
class-$\mathcal{S}$ and $\mathcal{N} = 4$ theories with $SU(N)$ gauge group. We
work out the modular orbit of the flavored index and defect index, compute the
dimension of the space spanned by the orbit, and provide complete basis for
computing modular transformation matrices. The dimension obtained from the
flavored analysis predicts the minimal order of the unflavored modular
differential equation satisfied by the unflavored Schur index. With the help of
modularity, we also study analytically the high-temperature asymptotics of the
Schur index. In the high-temperature limit $\tau \to +i0$, we identified the
(defect) Schur index of the genus-zero $A_1$ theories of class-$\mathcal{S}$
with the $S^3$-partition function of the $SU(2) \times U(1)^n$ star-shape
quiver (with Wilson line insertion). In the identification, we observe an
interesting relation between the linear-independence of defect indices and the
convergence of the Wilson line partition functions. | hep |
Falsifying High-Scale Leptogenesis at the LHC: Measuring a non-zero value for the cross section of any lepton number
violating (LNV) process would put a strong lower limit on the washout factor
for the effective lepton number density in the early universe at times close to
the electroweak phase transition and thus would lead to important constraints
on any high-scale model for the generation of the observed baryon asymmetry
based on LNV. In particular, for leptogenesis models with masses of the
right-handed neutrinos heavier than the mass scale observed at the LHC, the
implied large washout factors would lead to a violation of the
out-of-equilibrium condition and exponentially suppress the net lepton number
produced in such leptogenesis models. We thus demonstrate that the observation
of LNV processes at the LHC results in the falsification of high-scale
leptogenesis models. However, no conclusions about the viability of
leptogenesis models can be drawn from the non-observation of LNV processes. | hep |
Some Features of the Hadronic $B_c^{(*)}$-meson Production at Large
$p_T$: Calculations of the hadronic $B^{(*)}_c$-mesons production performed in the
framework of the perturbative QCD taking into account $O(\alpha_s^4)$ Feynmann
diagrams are presented. A comparison of the exact calculations with those based
on the fragmentation model of $\bar b\rightarrow B^{(*)}_c+X$ shows the large
discrepancy between them. The exact calculations of the $B^{(*)}_c$-mesons
production cross-sections as the function of $p_T$ at the energy of the FNAL
Tevatron ($\sqrt{s}=1.8$ TeV) are given. The predicted ratio of the vector to
the pseudoscalar state cross-sections is about $R\sim 3$ instead of $R\sim 1.4$
for the fragmentation model. | hep |
Duality Equivalence Between Self-Dual And Topologically Massive
Non-Abelian Models: The non-abelian version of the self-dual model proposed by Townsend, Pilch
and van Nieuwenhuizen presents some well known difficulties not found in the
abelian case, such as well defined duality operation leading to self-duality
and dual equivalence with the Yang-Mills-Chern-Simons theory, for the full
range of the coupling constant. These questions are tackled in this work using
a distinct gauge lifting technique that is alternative to the master action
approach first proposed by Deser and Jackiw. The master action, which has
proved useful in exhibiting the dual equivalence between theories in diverse
dimensions, runs into trouble when dealing with the non-abelian case apart from
the weak coupling regime. This new dualization technique on the other hand, is
insensitive of the non-abelian character of the theory and generalize
straightforwardly from the abelian case. It also leads, in a simple manner, to
the dual equivalence for the case of couplings with dynamical fermionic matter
fields. As an application, we discuss the consequences of this dual equivalence
in the context of 3D non-abelian bosonization. | hep |
Estimation of Power Corrections to Hadronic Event Shapes: Power corrections to hadronic event shapes are estimated using a recently
suggested relationship between perturbative and non-perturbative effects in
QCD. The infrared cutoff dependence of perturbative calculations is related to
non-perturbative contributions with the same dependence on the energy scale
$Q$. Corrections proportional to $1/Q$ are predicted, in agreement with
experiment. An empirical proportionality between the magnitudes of perturbative
and non-perturbative coefficients is noted. | hep |
Dark Matter Direct Detection in $t$-channel mediator models: We perform a comprehensive study of the Direct Detection phenomenology of
singlet Dark Matter $t$-channel portal models. For that purpose, we present a
complete one-loop matching onto a Heavy Dark-Matter Effective Field Theory,
leading to a complete computation of the loop induced direct detection
cross-section for both scalar and fermionic Dark Matter candidates. The results
are compared with current and future bounds from Direct Detection experiments,
as well as with the requirement of the correct Dark Matter relic density. | hep |
Probing the Sea Quark Content of the Proton with One-Particle-Inclusive
Processes: We investigate the feasibility of constraining parton distribution functions
in the proton through a comparison with data on semi-inclusive deep-inelastic
lepton-nucleon scattering. Specifically, we reweight replicas of these
distributions according to how well they reproduce recent, very precise charged
kaon multiplicity measurements and analyze how this procedure optimizes the
determination of the sea quark densities and improves their uncertainties. The
results can help to shed new light on the long standing question on the size of
the flavor and charge symmetry breaking among quarks of radiative origin. An
iterative method is proposed and adopted to account for the inevitable
correlation with what is assumed about the parton-to-hadron fragmentation
functions in the reweighting procedure. It is shown how the fragmentation
functions can be optimized simultaneously in each step of the iteration. As a
first case study, we implement this method to analyze kaon production data. | hep |
On the triplet anti-triplet symmetry in 3-3-1 models: We present a detailed discussion of the triplet anti-triplet symmetry in
3-3-1 models. The full set of conditions to realize this symmetry is provided,
which includes in particular the requirement that the two vacuum expectation
values of the two scalar triplets responsible for making the W and Z bosons
massive must be interchanged. We apply this new understanding to the
calculation of processes that have a Z-Z' mixing. | hep |
$L_{\infty}$ Algebras and Field Theory: We review and develop the general properties of $L_\infty$ algebras focusing
on the gauge structure of the associated field theories. Motivated by the
$L_\infty$ homotopy Lie algebra of closed string field theory and the work of
Roytenberg and Weinstein describing the Courant bracket in this language we
investigate the $L_\infty$ structure of general gauge invariant perturbative
field theories. We sketch such formulations for non-abelian gauge theories,
Einstein gravity, and for double field theory. We find that there is an
$L_\infty$ algebra for the gauge structure and a larger one for the full
interacting field theory. Theories where the gauge structure is a strict Lie
algebra often require the full $L_\infty$ algebra for the interacting theory.
The analysis suggests that $L_\infty$ algebras provide a classification of
perturbative gauge invariant classical field theories. | hep |
Sequential hadronization in heavy ion collisions: Heavy flavor supplies a chance to constrain and improve the hadronization
mechanism. We have established a sequential coalescence model with charm
conservation and applied it to the charmed hadron production in heavy ion
collisions. The charm conservation enhances the earlier hadron production and
suppresses the later production. This relative enhancement (suppression)
changes significantly the ratios between charmed hadrons in heavy ion
collisions. | hep |
Lectures on localization and matrix models in supersymmetric
Chern-Simons-matter theories: In these lectures I give a pedagogical presentation of some of the recent
progress in supersymmetric Chern-Simons-matter theories, coming from the use of
localization and matrix model techniques. The goal is to provide a simple
derivation of the exact interpolating function for the free energy of ABJM
theory on the three-sphere, which implies in particular the N^{3/2} behavior at
strong coupling. I explain in detail part of the background needed to
understand this derivation, like holographic renormalization, localization of
path integrals, and large N techniques in matrix models | hep |
Supersymmetry of Affine Toda Models as Fermionic Symmetry Flows of the
Extended mKdV Hierarchy: We couple two copies of the supersymmetric mKdV hierarchy by means of the
algebraic dressing technique. This allows to deduce the whole set of $(N,N)$
supersymmetry transformations of the relativistic sector of the extended mKdV
hierarchy and to interpret them as fermionic symmetry flows. The construction
is based on an extended Riemann-Hilbert problem for affine Kac-Moody
superalgebras with a half-integer gradation. A generalized set of
relativistic-like fermionic local current identities is introduced and it is
shown that the simplest one, corresponding to the lowest isospectral times
$t_{\pm 1}$ provides the supercharges generating rigid supersymmetry
transformations in 2D superspace. The number of supercharges is equal to the
dimension of the fermionic kernel of a given semisimple element $E \in
\widehat{\mathfrak{g}}$ which defines both, the physical degrees of freedom and
the symmetries of the model. The general construction is applied to the
$N=(1,1)$ and $N=(2,2)$ sinh-Gordon models which are worked out in detail. | hep |
On polarized scattering equations for superamplitudes of 11D
supergravity and ambitwistor superstring: We revisited the formalism of 11D polarized scattering equation by Geyer and
Mason from the perspective of spinor frame approach and spinor moving frame
formulation of the 11D ambitwistor superstring action. In particular, we
rigorously obtain the equation for the spinor function on Riemann sphere from
the supertwistor form of the ambitwistor superstring action, write its general
solution and use it to derive the polarized scattering equation. We show that
the expression used by Geyer and Mason to motivate their ansatz for the
solution of polarized scattering equation can be obtained from our solution
after a suitable gauge fixing. To this end we use the hidden gauge symmetries
of the 11D ambitwistor superstring, including $SO(16)$, and the description of
ambitwistor superstring as a dynamical system in an 11D superspace enlarged by
bosonic directions parametrized by 517 tensorial central charge coordinates
$Z^{\underline{\mu} \underline{\nu}}$ and
$Z^{\underline{\mu}\underline{\nu}\underline{\rho}\underline{\sigma}\underline{\kappa}}$.
We have also found the fermionic superpartner of the polarized scattering
equation. This happens to be a differential equation in fermionic variables
imposed on the superamplitude, rather then just a condition on the scattering
data as the bosonic polarized scattering equation is.
D=10 case is also discussed stressing the similarities and differences with
11D systems. The useful formulation of 10D ambitwistor superstring considers it
as a dynamical system in superspace enlarged with 126 tensorial central charge
coordinates $Z^{\mu\nu\rho\sigma\kappa}$. | hep |
A violation of global symmetries from replica wormholes and the fate of
black hole remnants: We show that the presence of replica wormholes in the Euclidean path integral
of gravity leads to a non-perturbative violation of charge conservation for any
global symmetry present in the low-energy description of quantum gravity.
Explicitly, we compute the scattering probability between different charged
states in several two-dimensional models of quantum gravity and find a
non-vanishing answer. This suggests that the set of all charged states is
typically over-complete, which has drastic consequences for the fate of black
hole remnants that could carry a global symmetry charge. In the holographic
context, we argue that the presence of such a symmetry in the effective
description of the bulk should appear on the boundary as an emergent global
symmetry after ensemble averaging. | hep |
Searching for the Higgs Boson(s): The ability of LEP-200, the Tevatron, the Di-Tevatron, the LHC, and a next
linear $\epem$ collider (NLC) to probe the Higgs sectors of the minimal
Standard Model (SM) and the Minimal Supersymmetric Model (MSSM) is reviewed.
Emphasis is placed on newly developed detection modes and on predictions for
supersymmetric particle Higgs decay channels when the MSSM is constrained using
boundary conditions motivated by supergravity/superstring models. | hep |
Non-thermal Higgs Spectrum in Reheating Epoch: Primordial Condensate vs.
Stochastic Fluctuation: Since electroweak symmetry is generally broken during inflation, the Standard
Model Higgs field can become supermassive even after the end of inflation. In
this paper, we study the non-thermal phase space distribution of the Higgs
field during reheating, focusing in particular on two different contributions:
primordial condensate and stochastic fluctuations. We obtain their analytic
formulae, which agree with the previous numerical result. As a possible
consequence of the non-thermal Higgs spectrum, we discuss perturbative Higgs
decay during reheating for the case it is kinematically allowed. We find that
the soft-relativistic and hard spectra are dominant in the decay rate of the
stochastic fluctuation and that the primordial condensate and stochastic
fluctuations decay almost at the same time. | hep |
Asymptotic description of finite lifetime effects on the photon emission
from a quark-gluon plasma: Direct photons play an important role as electromagnetic probes from the
quark-gluon plasma (QGP) which occurs during ultrarelativistic heavy-ion
collisions. In this context, it is of particular interest how the finite
lifetime of the QGP affects the resulting photon production. Earlier
investigations on this question were accompanied by a divergent contribution
from the vacuum polarization and by the remaining contributions not being
integrable in the ultraviolet (UV) domain. In this work, we provide a different
approach in which we do not consider the photon number density at finite times,
but for free asymptotic states obtained by switching the electromagnetic
interaction according to the Gell-Mann and Low theorem. This procedure
eliminates a possible unphysical contribution from the vacuum polarization and,
moreover, renders the photon number density UV integrable. It is emphasized
that the consideration of free asymptotic states is, indeed, crucial to obtain
such physically reasonable results. | hep |
Holographic Calculation of BMSFT Mutual and 3-partite Information: We use flat-space holography to calculate the mutual information and the
3-partite information of a two-dimensional BMS-invariant field theory
(BMSFT$_2$). This theory is the putative holographic dual of the
three-dimensional asymptotically flat spacetimes. We find a bound in which
entangling transition occurs for zero and finite temperature BMSFTs. We also
show that the holographic 3-partite information is always non-positive which
indicates that the holographic mutual information is monogamous. | hep |
Prospects for improved $Λ_c$ branching fractions: The experimental uncertainty on the branching fraction $\b(\Lambda_c \to p
K^- \pi^+) = (5.0 \pm 1.3)%$ has not decreased since 1998, despite a much
larger data sample. Uncertainty in this quantity dominates that in many other
quantities, including branching fractions of $\Lambda_c$ to other modes,
branching fractions of $b$-flavored baryons, and fragmentation fractions of
charmed and bottom quarks. Here we advocate a lattice QCD calculation of the
form factors in $\Lambda_c \to \Lambda \ell^+ \nu_\ell$ (the case $\ell = e^+$
is simpler as the mass of the lepton can be neglected). Such a calculation
would yield an absolute prediction for the rate for $\Lambda_c \to \Lambda
\ell^+ \nu_\ell$. When combined with the $\Lambda_c$ lifetime, it could provide
a calibration for an improved set of $\Lambda_c$ branching fractions as long as
the accuracy exceeds about 25%. | hep |
Transverse Energy Flow with Forward and Central Jets at the LHC: At the LHC, using forward + central detectors, it becomes possible for the
first time to carry out measurements of the transverse energy flow due to
``minijets" accompanying production of two jets separated by a large rapidity
interval. We discuss parton-shower calculations of energy flow observables in a
high-energy factorized Monte Carlo framework, and comment on the role of these
observables to study high parton multiplicity effects. | hep |
The LHC diphoton resonance and dark matter: A Higgs-like resonance with a mass of approximately 750 GeV has recently been
observed at the LHC in its diphoton decay. If this state is not simply a
statistical fluctuation which will disappear with more data, it will have
important implications not only for particle physics but also for cosmology. In
this note, we analyze the implications of such a resonance for the dark matter
(DM). Assuming a spin 1/2 DM particle, we first verify that indeed the correct
relic density can be obtain for a wide range of the particle mass and weak
scale coupling that are compatible with present data. We then show that the
combination of near future direct and indirect detection experiments will allow
to probe the CP-nature of the mediator resonance, i.e. check whether it is a
scalar or a pseudoscalar like particle. | hep |
Non-Abelian Vortices without Dynamical Abelianization: Vortices carrying truly non-Abelian flux moduli, which do not dynamically
reduce to Abelian vortices, are found in the context of softly-broken ${\cal
N}=2$ supersymmetric chromodynamics (SQCD). By tuning the bare quark masses
appropriately we identify the vacuum in which the underlying SU(N) gauge group
is partially broken to $SU(n) \times SU(r) \times U(1)/{\mathbbm Z}_{K}$, where
$K$ is the least common multiple of $(n, r)$, and with $N_{f}^{su(n)}=n$ and
$N_{f}^{su(r)}=r$ flavors of light quark multiplets. At much lower energies the
gauge group is broken completely by the squark VEVs, and vortices develop which
carry non-Abelian flux moduli $CP^{n-1}\times CP^{r-1}$. For $n>r$ we argue
that the SU(n) fluctuations become strongly coupled and Abelianize, while
leaving weakly fluctuating $SU(r)$ flux moduli. This allows us to recognize the
semi-classical origin of the light non-Abelian monopoles found earlier in the
fully quantum-mechanical treatment of 4D SQCD. | hep |
$h$-Deformation as a Contraction of $q$-Deformation: We show that $h$-deformation can be obtained, by a singular limit of a
similarity transformation, from $q$-deformation; to be specefic, we obtain
$\GL_h(2)$, its differential structure, its inhomogenous extension, and
$\Uh{\sl(2)}$ from their $q$-deformed counterparts. | hep |
Renormalization in Large Momentum Effective Theory of Parton Physics: In the large-momentum effective field theory approach to parton physics, the
matrix elements of non-local operators of quark and gluon fields, linked by
straight Wilson lines in a spatial direction, are calculated in lattice quantum
chromodynamics as a function of hadron momentum. Using the heavy-quark
effective theory formalism, we show a multiplicative renormalization of these
operators at all orders in perturbation theory, both in dimensional and lattice
regularizations. The result provides a theoretical basis for extracting parton
properties through properly renormalized observables in Monte Carlo
simulations. | hep |
Searching for physics beyond the Standard Model in the decay B+ ->
K+K+pi-: The observation potential of the decay B+ -> K+K+pi- with the ATLAS detector
at LHC is described in this paper. In the Standard Model this decay mode is
highly suppressed, while in models beyond the Standard Model it could be
significantly enhanced. To improve the selection of the K+K+pi- final state, a
charged hadron identification using Time-over-Threshold measurements in the
ATLAS Transition Radiation Tracker was developed and used. | hep |
Production and Decay of Di-photon Resonance at Future $e^+e^-$ Colliders: Motivated by the ATLAS and CMS announcements of the excesses of di-photon
events, we discuss the production and decay processes of di-photon resonance at
future $e^+e^-$ colliders. We assume that the excess of the di-photon events at
the LHC is explained by a scalar resonance decaying into a pair of photons. In
such a case, the scalar interacts with standard model gauge bosons and,
consequently, the production of such a scalar is possible at the $e^+e^-$
colliders. We study the production of the scalar resonance via the associated
production with photon or $Z$, as well as via the vector-boson fusion, and
calculate the cross sections of these processes. We also study the backgrounds,
and discuss the detectability of the signals of scalar production with various
decay processes of the scalar resonance. We also consider the case where the
scalar resonance has an invisible decay mode, and study how the invisible decay
can be observed at the $e^+e^-$ colliders. | hep |
Anomaly and long-range forces: We consider infrared dependences of chiral effects, like chiral magnetic
effect, in chiral media. The main observation is that there exist competing
infrared-sensitive parameters, sometimes not apparent. The value of the chiral
effects depends in fact on the actual hierarchy of the parameters. Some
examples have been already given in the literature. We argue that
magnetostatics of chiral media with a non-vanishing chiral chemical potential
$\mu_5\neq 0$ is also infrared sensitive. In particular, the system turns to be
unstable if the volume is large enough. The instability is with respect to the
decay of the system into domains of non-vanishing magnetic field with
non-trivial helicity. | hep |
The Feynman Variational Principle in the Worldline Representation of
Field Theory: Following Feynman's treatment of the non-relativistic polaron problem,
similar techniques are used to study relativistic field theories: after
integrating out the bosonic degrees of freedom the resulting effective action
is formulated in terms of particle trajectories (worldlines) instead of field
operators. The Green functions of the theory are then approximated
variationally on the pole of the external particles by using a retarded
quadratic trial action. Application to a scalar theory gives non-perturbative,
covariant results for vertex functions and scattering processes. Recent
progress in dealing with the spin degrees of freedom in fermionic systems, in
particular Quantum Electrodynamics, is discussed. We evaluate the averages
needed in the Feynman variational principle for a general quadratic trial
action and study the structure of the dressed fermion propagator. | hep |
Search for the double-charmonium state with $η_c J/ψ$ at Belle: We measure the cross section of $e^+e^-\rightarrow\eta_c J/\psi$ at the
$\Upsilon(nS) (n=1$ -- $5)$ on-resonance and 10.52 GeV off-resonance energy
points using the full data sample collected by the Belle detector with an
integrated luminosity of $955~\rm fb^{-1}$. We also search for double
charmonium production in $e^+e^-\rightarrow\eta_c J/\psi$ via initial state
radiation near the $\eta_c J/\psi$ threshold. No evident signal of the double
charmonium state is found, but evidence for the $e^+e^-\rightarrow\eta_c
J/\psi$ process is found with a statistical significance greater than
$3.3\sigma$ near the $\eta_c J/\psi$ threshold. The average cross section near
the threshold is measured and upper limits of cross sections are set for other
regions. | hep |
A $ν$ Approach to Analyzing Neutrino Data in the
$\mathbf{R}$-Parity-Violating MSSM: The $R$-parity-violating Minimal Supersymmetric Standard Model (RPV-MSSM) can
naturally accommodate massive neutrinos as required by the oscillation data.
However, studying the phenomenology is complicated due to the large number of
undetermined parameters involved. Thus, studies are usually restricted to
specific submodels. In this work, we develop an approach that allows us to be
less restrictive. Working in (almost) the completely general RPV-MSSM setting,
we analyze the structure of the neutrino mass matrix, and identify -- for the
case of two massive neutrinos -- only four minimal classes of structures that
can solve the neutrino data; we call these Minimal Oscillation Models (MOMs).
We study the general features of each MOM class, and present numerical fits to
the oscillation data. Our approach allows us to study all RPV models satisfying
the neutrino data in a unified manner, as long as they satisfy the MOM
criteria. Through several examples, we show that this indeed holds for many
interesting scenarios. | hep |
The Ultraviolet Properties of N=4 Supergravity at Four Loops: We demonstrate that pure N=4 supergravity is ultraviolet divergent at four
loops. The form of the divergence suggests that it is due to the rigid U(1)
duality-symmetry anomaly of the theory. This is the first known example of an
ultraviolet divergence in a pure ungauged supergravity theory in four
dimensions. We use the duality between color and kinematics to construct the
integrand of the four-loop four-point amplitude, whose ultraviolet divergence
is then extracted by standard integration techniques. | hep |
Reconstruction of moments of particle distributions with Identity Method
at MPD: Precise determination of the moments of multiplicity distributions of
identified particles could be challenging due to the misidentification in
detectors. The so-called Identity Method allows one to solve this problem. In
this contribution, performance of the Identity Method was tested on the A-A
events simulated in the conditions of the MPD experiment at NICA. With this
method, moments within a single kinematic window as well as coefficients of
forward-backward pseudorapidity correlations are extracted. | hep |
Alternativity and reciprocity in the Cayley-Dickson algebra: We calculate the eigenvalue \rho of the multiplication mapping R on the
Cayley-Dickson algebra A_n. If the element in A_n is composed of a pair of
alternative elements in A_{n-1}, half the eigenvectors of R in A_n are still
eigenvectors in the subspace which is isomorphic to A_{n-1}.
The invariant under the reciprocal transformation A_n \times A_{n} \ni (x,y)
-> (-y,x) plays a fundamental role in simplifying the functional form of \rho.
If some physical field can be identified with the eigenspace of R, with an
injective map from the field to a scalar quantity (such as a mass) m, then
there is a one-to-one map \pi: m \mapsto \rho. As an example, the electro-weak
gauge field can be regarded as the eigenspace of R, where \pi implies that the
W-boson mass is less than the Z-boson mass, as in the standard model. | hep |
Searching for new homogeneous sine-Gordon theories using T-duality
symmetries: The Homogeneous sine-Gordon (HSG) theories are integrable perturbations of
$G_k/U(1)^{r_G}$ coset CFTs, where $G$ is a simple compact Lie group of rank
$r_G$ and $k>1$ is an integer. Using their T-duality symmetries, we investigate
the relationship between the different theories corresponding to a given coset,
and between the different phases of a particular theory. Our results suggest
that for $G=SU(n)$ with $n\geq5$ and $E_6$ there could be two non-equivalent
HSG theories associated to the same coset, one of which has not been considered
so far. | hep |
Geometrical aspects of chiral anomalies in the overlap: The set of one dimensional lowest energy eigenspaces used to construct the
overlap induces a two form on gauge orbit space which is the locally exact curl
of Berry's connection. If anomalies do not cancel, examples of two dimensional
closed sub-manifolds of orbit space are produced over which the integral of the
above two form does not vanish. Based on these observations, a natural
definition of covariant currents is obtained, a simple way to calculate chiral
anomalies on the lattice is found, and indications for how to construct an
ideal regularization of chiral gauge theories are seen to emerge. | hep |
Landau levels for graphene layers in noncommutative plane: Starting from the zero modes of the single and bilayer graphene Hamiltonians
we develop a mechanism to construct the eigenstates and eigenenergies for
Landau levels in noncommutative plane. General formulas for the spectrum of
energies are deduced, for both cases, single and bilayer graphene. In both
cases we find that the effect to introduce noncommutative coordinates is a
shift in the energy spectrum with respect to result obtained in commutative
space. | hep |
Large spin limit of AdS_5 x S^5 string theory and low energy expansion
of ferromagnetic spin chains: By considering AdS_5 x S^5 string states with large angular momenta in S^5
one is able to provide non-trivial quantitative checks of the AdS/CFT duality.
A string rotating in S^5 with two angular momenta J_1,J_2 is dual to an
operator in N=4 SYM theory whose conformal dimension can be computed by
diagonalizing a (generalization of) spin 1/2 Heisenberg chain Hamiltonian. It
was recently argued and verified to lowest order in a large J=J_1+J_2
expansion, that the Heisenberg chain can be described using a non-relativistic
low energy effective 2-d action for a unit vector field n_i which exactly
matches the corresponding large J limit of the classical AdS_5 x S^5 string
action. In this paper we show that this agreement extends to the next order and
develop a systematic procedure to compute higher orders in such large angular
momentum expansion. This involves several non-trivial steps. On the string
side, we need to choose a special gauge with a non-diagonal world-sheet metric
which insures that the angular momentum is uniformly distributed along the
string, as indeed is the case on the spin chain side. We need also to implement
an order by order redefinition of the field n_i to get an action linear in the
time derivative. On the spin chain side, it turns out to be crucial to include
the effects of integrating out short wave-length modes. In this way we gain a
better understanding of how (a subsector of) the string sigma model emerges
from the dual gauge theory, allowing us to demonstrate the duality beyond
comparing particular examples of states with large J. | hep |
The DUNE Far Detector Vertical Drift Technology, Technical Design Report: DUNE is an international experiment dedicated to addressing some of the
questions at the forefront of particle physics and astrophysics, including the
mystifying preponderance of matter over antimatter in the early universe. The
dual-site experiment will employ an intense neutrino beam focused on a near and
a far detector as it aims to determine the neutrino mass hierarchy and to make
high-precision measurements of the PMNS matrix parameters, including the
CP-violating phase. It will also stand ready to observe supernova neutrino
bursts, and seeks to observe nucleon decay as a signature of a grand unified
theory underlying the standard model.
The DUNE far detector implements liquid argon time-projection chamber
(LArTPC) technology, and combines the many tens-of-kiloton fiducial mass
necessary for rare event searches with the sub-centimeter spatial resolution
required to image those events with high precision. The addition of a photon
detection system enhances physics capabilities for all DUNE physics drivers and
opens prospects for further physics explorations. Given its size, the far
detector will be implemented as a set of modules, with LArTPC designs that
differ from one another as newer technologies arise.
In the vertical drift LArTPC design, a horizontal cathode bisects the
detector, creating two stacked drift volumes in which ionization charges drift
towards anodes at either the top or bottom. The anodes are composed of
perforated PCB layers with conductive strips, enabling reconstruction in 3D.
Light-trap-style photon detection modules are placed both on the cryostat's
side walls and on the central cathode where they are optically powered.
This Technical Design Report describes in detail the technical
implementations of each subsystem of this LArTPC that, together with the other
far detector modules and the near detector, will enable DUNE to achieve its
physics goals. | hep |
A Renormalization Group Approach to A Yang-Mills Two Matrix Model: A Yang-Mills type two matrix model with mass terms is studied by use of a
matrix renormalization group approach proposed by Brezin and Zinn-Justin. The
renormalization group method indicates that the model exhibits a critical
behavior similar to that of two dimensional Euclidean gravity. A massless limit
and the generation of quadratic terms along the renormalization group flow are
discussed. | hep |
Transverse Momentum Dependent Distributions in Hadronic Collisions:
p(transv. polarized) p --> D + X and p(transv. polarized) p --> gamma + X: Our understanding of the transverse spin structure of hadrons might
definitely get improved by the information we gather on transverse momentum
dependent (TMD) distributions. These new functions could also be crucial for a
description of the observed transverse single spin asymmetries (SSA). In a hard
scattering model for inclusive hadronic reactions, based on a generalized QCD
factorization scheme, many mechanisms - namely the Sivers, Collins,
Boer-Mulders effects - might contribute to a SSA. We show how the k_T dependent
phases arising from the partonic kinematics together with a suitable choice of
experimental configurations could help in disentangling the above mentioned
effects. We discuss their potential role in two inclusive hadronic processes:
heavy meson and photon production in pp and p pbar collisions. | hep |
Gravitational Black Hole Hair from Event Horizon Supertranslations: We discuss BMS supertranslations both at null-infinity and on the horizon for
the case of the Schwarzschild black hole. We show that both kinds of
supertranslations lead to infinetly many gapless physical excitations. On this
basis we construct a quotient algebra using suited superpositions of both kinds
of transformations which cannot be compensated by an ordinary
BMS-supertranslation and therefore are intrinsically due to the presence of an
event horizon. We show that these quotient transformations are physical and
generate gapless excitations on the horizon that can account for the
gravitational hair as well as for the black hole entropy. We identify the
physics of these modes as associated with Bogolioubov-Goldstone modes due to
quantum criticality. Classically the number of these gapless modes is infinite.
However, we show that due to quantum criticality the actual amount of
information-carriers becomes finite and consistent with Bekenstein entropy.
Although we only consider the case of Schwarzschild geometry, the arguments are
extendable to arbitrary space-times containing event horizons. | hep |
Loop effects on the Higgs decay widths in extended Higgs models: In order to identify the Higgs sector using future precision data, we
calculate the partial decay widths of the discovered Higgs boson with the mass
of 125 GeV into fermion pairs and gauge-boson pairs with one-loop electroweak
and one-loop QCD corrections in various extended Higgs models, such as the
Higgs singlet model and four types of two Higgs doublet models. In the
tree-level analysis, the patterns of deviations from the standard model
predictions in the partial decay widths for various decay modes are distinctive
for each model, due to the mixing of the Higgs boson with other neutral
scalars. Our present analysis shows that even with a full set of radiative
corrections we can discriminate these extended Higgs models via the partial
decay widths as long as any of the deviations is detected at future precision
measurements. Furthermore, we quantitatively show that in each model the
magnitude of the deviations can provide important information on the mass scale
of extra Higgs bosons under the theoretical constraints from perturbative
unitary and vacuum stability, which can be obtained without discovery of the
additional Higgs bosons. | hep |
Applications of intersection numbers in physics: In this review I discuss intersection numbers of twisted cocycles and their
relation to physics. After defining what these intersection number are, I will
first discuss a method for computing them. This is followed by three examples
where intersection numbers appear in physics. These examples are: tree-level
scattering amplitudes within the the CHY-formalism, reduction of Feynman
integrals to master integrals and correlation functions on the lattice. | hep |
Topologically Induced Instability in String Theory: Using the generalised AdS/CFT correspondence, we show that there are certain
ten-dimensional differentiable manifolds such that string theory on such a
manifold is unstable [to the emission of "large branes"] no matter what the
metric may be. The instability is thus due to the [differential] topology of
the manifold, not to any particular choice of its geometry. We propose a
precise criterion for this "topology selection mechanism", and prove it in many
cases. The techniques employed may be useful in more general cases. | hep |
Anisotropic Inflation with General Potentials: Anomalies in recent observational data indicate that there might be some
"anisotropic hair" generated in an inflation period. To obtain general
information about the effects of this anisotropic hair to inflation models, we
studied anisotropic inflation models that involve one vector and one scalar
using several types of potentials. We determined the general relationship
between the degree of anisotropy and the fraction of the vector and scalar
fields, and concluded that the anisotropies behave independently of the
potentials. We also generalized our study to the case of multi-directional
anisotropies. | hep |
Self-Gravitational Corrections to the Cardy-Verlinde Formula and the FRW
Brane Cosmology in SdS_5 Bulk: The semiclassical corrections to the Cardy-Verlinde entropy of a
five-dimensional Schwarzschild de-Sitter black hole (SdS_5) are explicitly
evaluated. These corrections are considered within the context of KKW analysis
and arise as a result of the self-gravitation effect. In addition, a
four-dimensional spacelike brane is considered as the boundary of the SdS_5
bulk background. It is already known that the induced geometry of the brane is
exactly given by that of a radiation-dominated FRW universe. By exploiting the
CFT/FRW-cosmology relation, we derive the self-gravitational corrections to the
first Friedmann-like equation which is the equation of the brane motion. The
additional term that arises due to the semiclassical analysis can be viewed as
stiff matter where the self-gravitational corrections act as the source for it.
This result is contrary to standard analysis that regards the charge of SdS_5
bulk black hole as the source for stiff matter. Furthermore, we rewrite the
Friedmann-like equation in a such way that it represents the conservation
equation of energy of a point particle moving in a one-dimensional effective
potential. The self-gravitational corrections to the effective potential and,
consequently, to the point particle's motion are obtained. A short analysis on
the asymptotic behavior of the 4-dimensional brane is presented. | hep |
A Fake Split Supersymmetry Model for the 126 GeV Higgs: We consider a scenario where supersymmetry is broken at a high energy scale,
out of reach of the LHC, but leaves a few fermionic states at the TeV scale.
The particle content of the low-energy effective theory is similar to that of
Split Supersymmetry. However, the gauginos and higgsinos are replaced by
fermions carrying the same quantum numbers but having different couplings,
which we call fake gauginos and fake higgsinos. We study the prediction for the
light-Higgs mass in this Fake Split SUSY Model (FSSM). We find that, in
contrast to Split or high-scale supersymmetry, a 126 GeV Higgs boson is easily
obtained even for arbitrarily high values of the supersymmetry scale. For a
supersymmetry scale greater than roughly 100 PeV, the Higgs mass is almost
independent of the supersymmetry scale and the stop mixing parameter, while the
observed value is achieved for tan beta between 1.3 and 1.8 depending on the
gluino mass. | hep |
Proceedings of 15th conference on Elastic and Diffractive scattering
(EDS Blois 2013): This volume represents the proceedings of the 15th conference on Elastic and
Diffractive scattering, EDS Blois 2013. The conference was held in Saariselka,
Finland on September 9th-13th, 2013. | hep |
Forward jet-like event spin-dependent properties in polarized p+p
collisions at $\sqrt{s}$=200 GeV: The STAR collaboration has reported precision measurements on the transverse
single spin asymmetries for the production of forward $\pi^0$ mesons from
polarized proton collisions at $\sqrt{s} =\,$200 GeV. To disentangle the
contributions to forward asymmetries, one has to look beyond inclusive $\pi^0$
production to the production of forward jets or direct photons. Present forward
detector capabilities are not well matched to the complete reconstruction of
forward jets, but do have sufficient acceptance for "jet-like" events.
"Jet-like" events are the clustered response of an electromagnetic calorimeter
that is primarily sensitive to incident photons, electrons and positrons.
During the RHIC running in the year 2006, STAR with the Forward Pion Detector
(FPD++) in place collected 6.8 pb$^{-1}$ of data with an average polarization
of 60%. FPD++ was a modular detector prototype of the Forward Meson
Spectrometer (FMS) that consisted of two detectors placed symmetrically with
respect to the beam line at a distance of 7.4 m from the interaction point.
Readout of the FPD++ was triggered when the sum of energies in the central
module of the calorimeter used for $\pi^0$ measurements was larger than a
threshold. This trigger minimizes the bias for "jet-like" events, making it
appropriate to disentangling contributions to the forward transverse spin
asymmetries. We report on the status of the analysis. | hep |
Dimensional Transmutation and Dimensional Regularization in Quantum
Mechanics. I. General Theory: This is the first in a series of papers addressing the phenomenon of
dimensional transmutation in nonrelativistic quantum mechanics within the
framework of dimensional regularization. Scale-invariant potentials are
identified and their general properties are derived. A strategy for dimensional
renormalization of these systems in the strong-coupling regime is presented,
and the emergence of an energy scale is shown, both for the bound-state and
scattering sectors. Finally, dimensional transmutation is explicitly
illustrated for the two-dimensional delta-function potential. | hep |
Living on the edge in a spacetime with multiple warping: The Randall-Sundrum warped braneworld model is generalised to six and higher
dimensions such that the warping has a non-trivial dependence on more than one
dimension. This naturally leads to a brane-box like configuration alongwith
scalar fields with possibly interesting cosmological roles. Also obtained
naturally are two towers of 3 branes with mass scales clustered around either
of Planck scale and TeV scale. Such a scenario has interesting phenomenological
consequences including an explanation for the observed hierarchy in the masses
of standard model fermions. | hep |
Strong field limit of the Born-Infeld p-form electrodynamics: We study the strong field limit of p-form Born-Infeld theory. It turns out
that this limiting theory is a unique theory displaying the full symmetry group
of the underlying canonical structure. Moreover, being a nonlinear theory, it
possesses an infinite hierarchy of conservation laws. | hep |
Renormalization of Lorentz violating theories: We classify the unitary, renormalizable, Lorentz violating quantum field
theories of interacting scalars and fermions, obtained improving the behavior
of Feynman diagrams by means of higher space derivatives. Higher time
derivatives are not generated by renormalization. Renormalizability is ensured
by a "weighted power counting" criterion. The theories contain a dimensionful
parameter, yet a set of models are classically invariant under a weighted scale
transformation, which is anomalous at the quantum level. Formulas for the
weighted trace anomaly are derived. The renormalization-group properties are
studied. | hep |
Observation of a new $Ξ_b^0$ state: Using a proton-proton collision data sample collected by the LHCb experiment,
corresponding to an integrated luminosity of 8.5 fb$^{-1}$, the observation of
a new excited $\Xi_b^0$ resonance decaying to the $\Xi_b^-\pi^+$ final state is
presented. The state, referred to as $\Xi_b(6227)^0$, has a measured mass and
natural width of
$m(\Xi_b(6227)^0) = 6227.1^{\,+1.4}_{\,-1.5}\pm0.5$ MeV,
$\Gamma(\Xi_b(6227)^0) = 18.6^{\,+5.0}_{\,-4.1}\pm1.4$ MeV, where the
uncertainties are statistical and systematic. The production rate of the
$\Xi_b(6227)^0$ state relative to that of the $\Xi_b^-$ baryon in the kinematic
region $2<\eta<5$ and $p_{\rm T}<30$ GeV is measured to be
$\frac{f_{\Xi_b(6227)^0}}{f_{\Xi_b^-}}{\mathcal{B}}(\Xi_b(6227)^0\to\Xi_b^-\pi^+)
= 0.045\pm0.008\pm0.004$, where ${\mathcal{B}}(\Xi_b(6227)^0\to\Xi_b^-\pi^+)$
is the branching fraction of the decay, and $f_{\Xi_b(6227)^0}$ and
$f_{\Xi_b^-}$ represent fragmentation fractions.
Improved measurements of the mass and natural width of the previously
observed $\Xi_b(6227)^-$ state, along with the mass of the $\Xi_b^-$ baryon,
are also reported. Both measurements are significantly more precise than, and
consistent with, previously reported values. | hep |
Thermal power spectrum in the CFT driven cosmology: We present an overview of the recently suggested cosmological model driven by
conformal field theory (CFT) with the initial conditions in the form of the
microcanonical density matrix. In particular, we discuss the origin of
inflationary stage in this model and a novel feature -- the thermal nature of
the primordial power spectrum of the CMB anisotropy. The relevant effect of
"temperature of the relic temperature anisotropy" can be responsible for a
thermal contribution to the red tilt of this spectrum, additional to its
conventional vacuum component. The amplification of this effect due to recently
established $a$-theorem in CFT is briefly discussed. | hep |
Nucleon Magnetic Moments and Electric Polarizabilities: Electromagnetic properties of the nucleon are explored with lattice QCD using
a novel technique. Focusing on background electric fields, we show how the
electric polarizability can be extracted from nucleon correlation functions. A
crucial step concerns addressing contributions from the magnetic moment, which
affects the relativistic propagation of nucleons in electric fields. By
properly handing these contributions, we can determine both magnetic moments
and electric polarizabilities. Lattice results from anisotropic clover lattices
are presented. Our method is not limited to the neutron; we show results for
the proton as well. | hep |
Kinetic theory of a longitudinally expanding system: We use kinetic theory in order to study the role of quantum fluctuations in
the isotropization of the pressure tensor in a system subject to fast
longitudinal expansion, such as the matter produced in the early stages of a
heavy ion collision. | hep |
The bottomonium spectrum at finite temperature from $N_f=2+1$ lattice
QCD: We present results on the bottomonium spectrum at temperatures above and
below the deconfinement crossover temperature, $T_c$, from dynamical lattice
QCD simulations. The heavy quark is treated with a non-relativistic effective
field theory on the lattice and serves as a probe of the hot medium. Ensembles
with a finer spatial lattice spacing and a greater range of temperatures below
$T_c$ than those previously employed by this collaboration are used. In
addition, there are $N_f=2+1$ flavours of Wilson clover quark in the sea with
$M_\pi\approx400$ MeV and we perform a more careful tuning of the bottom quark
mass in this work. We calculate the spectral functions of S and P wave
bottomonium states using the maximum entropy method and confirm earlier
findings on the survival of the ground state S wave states up to at least
$2T_c$ and the immediate dissociation of the P wave states above $T_c$. | hep |
Interplay of Infrared Divergences and Gauge-Dependence of the Effective
Potential: The perturbative effective potential suffers infrared (IR) divergences in
gauges with massless Goldstones in their minima (like Landau or Fermi gauges)
but the problem can be fixed by a suitable resummation of the Goldstone
propagators. When the potential minimum is generated radiatively,
gauge-independence of the potential at the minimum also requires resummation
and we demonstrate that the resummation that solves the IR problem also cures
the gauge-dependence issue, showing this explicitly in the Abelian Higgs model
in Fermi gauge. In the process we find an IR divergence (in the location of the
minimum) specific to Fermi gauge and not appreciated in recent literature. We
show that physical observables can still be computed in this gauge and we
further show how to get rid of this divergence by a field redefinition. All
these results generalize to the Standard Model case. | hep |
A relation between CP violation of low energy and leptogenesis: We discuss how CP violation generating lepton number asymmetry can be related
to CP violation in low energy. | hep |
QCD Corrections to Higgs Boson Production: We discuss the ${\cal O}(\alpha_s)$
QCD radiative corrections to Higgs boson production in the limit in which the
top quark is much heavier than the Higgs boson. The subleading corrections, of
${\cal O} (\alpha_s M_H^2/M_{\rm top}^2)$, are presented for the decay
$H\rightarrow \gamma\gamma$ and shown to be small. | hep |
Real next-to-next-to-leading-order QCD corrections to J/psi and Upsilon
hadroproduction in association with a photon: We update the study of the QCD corrections to direct J/psi and Upsilon
hadroproduction in association with a photon in the QCD-based approach of the
Colour-Singlet (CS) Model. After comparison with the recent full
next-to-leading-order (NLO) computation for this process, we provide an
independent confirmation to the inclusive case that NLO QCD corrections to
quarkonium-production processes whose LO exhibits a non-leading P_T behaviour
can be reliably computed at mid and large P_T by considering only the real
emission contributions accompanied with a kinematical cut. In turn, we evaluate
the leading part of the alpha^4_S alpha contributions, namely those coming from
(J/psi,Upsilon)+gamma associated with two light partons. We find that they are
dominant at mid and large P_T. This confirms our expectations from the leading
P_T scaling of the new topologies appearing at NNLO. We obtain that the yield
from the CS becomes one order of magnitude larger than the upper value of the
potential Colour-Octet yield. The polarization of the 3S1 quarkonia produced in
association with a photon is confirmed to be longitudinal at mid and large P_T. | hep |
Towards Order alpha_s^4 Accuracy in tau-decays: Recently computed terms of orders O(\alpha_s^4 n_f^2) in the perturbative
series for the tau decay rate, and similar (new) strange quark mass
corrections, are used to discuss the validity of various optimization schemes.
The results are then employed to arrive at improved predictions for the
complete terms order O(\alpha_s^4) and O(\alpha_s^5) in the massless limit as
well as for terms due to the strange quark mass. Phenomenological implications
are presented. | hep |
Brown-Teitelboim Instantons and the First Law of Thermodynamics of
(Anti) de Sitter Space: We study the instantons (or bounces) in the Brown-Teitelboim (BT) mechanism
of relaxation of cosmological constant which is a cosmological version of the
Schwinger mechanism. The BT mechanism is a false vacuum decay of (A)dS$_{d+1}$
(and $R^{1, d}$) spaces via spontaneous nucleations of spherical $(d-1)$-branes
and thus ostensibly has bearings on (A)dS$_{d+1}$/CFT$_d$ holography. In this
paper we focus on the four-dimensional case, although the higher or
lower-dimensional generalization is straightforward. As is the case with pair
productions near black hole and de Sitter horizons, we show that the BT
instanton action for a membrane nucleation encodes the first law of
thermodynamics of (Anti) de Sitter space. In particular, the membrane instanton
precisely accounts for the change of entropy of (A)dS space before and after
nucleation, in good accordance with AdS$_{d+1}$/CFT$_d$ in which the
$(d-1)$-branes make up all degrees of freedom of AdS$_{d+1}$ space. In light of
this lesser-known perspective presented here we also make remarks on (1)
(A)dS/CFT and (2) complexity. For the complexity we observe that the Lorentzian
bounce action may have close connection to complexity. | hep |
On Quiver W-algebras and Defects from Gauge Origami: In this note, using Nekrasov's gauge origami framework, we study two
different versions of the the BPS/CFT correspondence - first, the standard AGT
duality and, second, the quiver W algebra construction which has been developed
recently by Kimura and Pestun. The gauge origami enables us to work with both
dualities simultaneously and find exact matchings between the parameters. In
our main example of an A-type quiver gauge theory, we show that the
corresponding quiver qW-algebra and its representations are closely related to
a large-n limit of spherical gl(n) double affine Hecke algebra whose modules
are described by instanton partition functions of a defect quiver theory. | hep |
Stuckelberg Axions and the Effective Action of Anomalous Abelian Models
1. A unitarity analysis of the Higgs-axion mixing: We analyze the quantum consistency of anomalous abelian models and of their
effective field theories, rendered anomaly-free by a Wess-Zumino term, in the
case of multiple abelian symmetries. These models involve the combined
Higgs-Stuckelberg mechanism and predict a pseudoscalar axion-like field that
mixes with the goldstones of the ordinary Higgs sector. We focus our study on
the issue of unitarity of these models both before and after spontaneous
symmetry breaking and detail the set of Ward identities and the organization of
the loop expansion in the effective theory. The analysis is performed on simple
models where we show, in general, the emergence of new effective vertices
determined by certain anomalous interactions. | hep |
Photon-photon scattering from a UV-complete gravity QFT: Quantum quadratic gravity (QQG) produces a tree-level differential cross
section for $\gamma\gamma\to\gamma\gamma$ that is well-behaved at all energies.
From this we can study how the corrections to low energy scattering amplitudes
are related to the UV physics, in particular to the exchange of the massive
graviparticles. An effective forward scattering amplitude is obtained by
separating out the effects of the $t$-channel graviton pole. This is possible
due to the UV-completeness, and even though the Froissart bound is not
satisfied. We then consider photon-photon scattering to two graviparticles and
a further imaginary contribution to the $\gamma\gamma\to\gamma\gamma$ forward
scattering amplitude. Unitarity without positivity is a key property of QQG and
it impacts all our results. | hep |
Unique Identification of Lee-Wick Gauge Bosons at Linear Colliders: Grinstein, O'Connell and Wise have recently presented an extension of the
Standard Model (SM), based on the ideas of Lee and Wick (LW), which
demonstrates an interesting way to remove the quadratically divergent
contributions to the Higgs mass induced by radiative corrections. This model
predicts the existence of negative-norm copies of the usual SM fields at the
TeV scale with ghost-like propagators and negative decay widths, but with
otherwise SM-like couplings. In earlier work, it was demonstrated that the LW
states in the gauge boson sector of these models, though easy to observe,
cannot be uniquely identified as such at the LHC. In this paper, we address the
issue of whether or not this problem can be resolved at an $e^+e^-$ collider
with a suitable center of mass energy range. We find that measurements of the
cross section and the left-right polarization asymmetry associated with Bhabha
scattering can lead to a unique identification of the neutral electroweak gauge
bosons of the Lee-Wick type. | hep |
Reparametrization Invariance and Partial Re-Summations of the Heavy
Quark Expansion: We extend existing work on reparametrization invariance (RPI) of the
heavy-quark expansion. We discuss the total rates of inclusive processes and
obtain results which have a manifest RPI and can be expressed through matrix
elements of operators and states defined in full QCD. This approach leads to a
partial re-summation of higher-order terms in the heavy-quark expansion and has
the advantage that the number of independent parameters is reduced. | hep |
The Consistent Result of Cosmological Constant From Quantum Cosmology
and Inflation with Born-Infeld Scalar Field: The Quantum cosmology with Born-Infeld(B-I) type scalar field is considered.
In the extreme limits of small cosmological scale factor the wave function of
the universe can also be obtained by applying the methods developed by
Hartle-Hawking(H-H) and Vilenkin. H-H wave function predicts that most Probable
cosmological constant $\Lambda$ equals to $\frac{1}{\eta}$($\frac{1}{2\eta}$
equals to the maximum of the kinetic energy of scalar field). It is different
from the original results($\Lambda=0$) in cosmological constant obtained by
Hartle-Hawking. The Vilenkin wave function predicts a nucleating unverse with
largest possible cosmological constant and it is larger than $1/\eta$. The
conclusions have been nicely to reconcile with cosmic inflation. We investigate
the inflation model with B-I type scalar field, and find that $\eta$ depends on
the amplitude of tensor perturbation $\delta_h$, with the form
$\frac{1}{\eta}\simeq \frac{m^2}{12\pi[(\frac{9\delta_{\Phi}^2}{N
\delta_h^2})^2-1]}.$ The vacuum energy in inflation epoch depends on the
tensor-to-scalar ratio $\frac{\delta_h}{\delta_{\Phi}}$. The amplitude of the
tensor perturbation ${\delta_{h}}$ can, in principle, be large enough to be
discovered. However, it is only on the border of detectability in future
experiments. If it has been observed in future, this is very interesting to
determine the vacuum energy in inflation epoch. | hep |
Symmetry transformations in Batalin-Vilkovisky formalism: This short note is closely related to Sen-Zwiebach paper on gauge
transformations in Batalin-Vilkovisky theory (hep-th 9309027). We formulate
some conditions of physical equivalence of solutions to the quantum master
equation and use these conditions to give a very transparent analysis of
symmetry transformations in BV-approach. We prove that in some sense every
quantum observable (i.e. every even function $H$ obeying
$\Delta_{\rho}(He^S)=0$) determines a symmetry of the theory with the action
functional $S$ satisfying quantum master equation $\Delta_{\rho}e^S=0$ \end | hep |
Symmetry Nonrestoration in a Gross-Neveu Model with Random Chemical
Potential: We study the symmetry behavior of the Gross-Neveu model in three and two
dimensions with random chemical potential. This is equivalent to a four-fermion
model with charge conjugation symmetry as well as Z_2 chiral symmetry. At high
temperature the Z_2 chiral symmetry is always restored. In three dimensions the
initially broken charge conjugation symmetry is not restored at high
temperature, irrespective of the value of the disorder strength. In two
dimensions and at zero temperature the charge conjugation symmetry undergoes a
quantum phase transition from a symmetric state (for weak disorder) to a broken
state (for strong disorder) as the disorder strength is varied. For any given
value of disorder strength, the high-temperature behavior of the charge
conjugation symmetry is the same as its zero-temperature behavior. Therefore,
in two dimensions and for strong disorder strength the charge conjugation
symmetry is not restored at high temperature. | hep |
TASI lectures on quantum matter (with a view toward holographic duality): These are notes from my lectures at TASI 2015. The goal is to provide context
for the study of strongly-correlated quantum many-body systems using quantum
field theory, and possibly string theory. | hep |
pi-pi Scattering in Twisted Mass Chiral Perturbation Theory: In this report we describe both I=2 and I=0 pi-pi scattering for twisted mass
lattice QCD utilizing twisted mass chiral perturbation theory at
next-to-leading order. Focusing on the lattice spacing (b) corrections, we
demonstrate that in the exotic I=2, I_3=+-2 channels, the leading scaling
violations of pi-pi scattering at maximal twist begin at O(m_pi^2 b^2). This is
not the case in any other isospin channel, for which the scaling violations at
maximal twist begin at O(b^2). Furthermore, we demonstrate the existence of a
mixing between the I=2, I_3 = 0 and I=0 scattering channels due to the breaking
of isospin symmetry by the twisted mass term. The mixing term, although
formally next-to-leading order, is relatively large, thus necessitating the use
of a coupled channel analysis. We argue that this mixing likely renders the
computation of the I=0 channel impractical with twisted mass lattice QCD. | hep |
Constraints on the geometry of branes from massive gauge invariant
vector KK modes: We investigate the gauge invariance of massive vector Kaluza-Klein (KK) modes
in different brane models with two extra dimensions. We demonstrate that some
additional constraint conditions on the geometry of branes are needed in order
to get the gauge invariant effective action of the KK modes. Nevertheless, not
all the conditions can be satisfied by the solutions of the branes, which will
break the gauge invariance. Moreover, in the branes where the conditions can
meet the brane solutions, we calculate mass spectra of vector and scalar KK
modes, and the results show that when only one kind of scalar KK modes is found
to be massive, the gauge invariance will also be broken. | hep |
Patterns of gauge symmetry in the background field method: The correlation functions of Yang-Mills theories formulated in the background
field method satisfy linear Slavnov-Taylor identities, which are naive
generalizations of simple tree level relations, with no deformations
originating from the ghost sector of the theory. In recent years, a stronger
version of these identities has been found to hold at the level of the
background gluon self-energy, whose transversality is enforced separately for
each special block of diagrams contributing to the gluon Schwinger-Dyson
equation. In the present work we demonstrate by means of explicit calculations
that the same distinct realization of the Slavnov-Taylor identity persists in
the case of the background three-gluon vertex. The analysis is carried out at
the level of the exact Schwinger-Dyson equation for this vertex, with no
truncations or simplifying assumptions. The demonstration entails the
contraction of individual vertex diagrams by the relevant momentum, which
activates Slavnov-Taylor identities of vertices and multi-particle kernels
nested inside these graphs; the final result emerges by virtue of a multitude
of extensive cancellations, without the need of performing explicit
integrations. In addition, we point out that background Ward identities amount
to replacing derivatives of propagators by zero-momentum background-gluon
insertions, in exact analogy to standard properties of Abelian gauge theories.
Finally, certain potential applications of these results are briefly discussed. | hep |
On Hpp-wave/CFT_2 Holography: We briefly review the AdS3/CFT2 correspondence and the holographic issues
that arise in the Penrose limit. Exploiting current algebra techniques,
developped by D'Appollonio and Kiritsis for the closely related Nappi-Witten
model, we obtain preliminary results for bosonic string amplitudes in the
resulting Hpp-wave background and comment on how to extend them to the
superstring. | hep |
Nonrelativistic Cousin of QCD: Based on the uniqueness and universality of gravity, it is clear that
theories with different dynamical exponents are related in the holographic
approach. Concretely, we construct an M-theory background from pure QCD dual
and show that a deformed $Sch_{6}^{4}$ geometry is obtained by compactification
from the same background. The deformed $Sch_{6}^{4}$ geometry is considered as
the geometrical realization of a four-dimensional nonrelativistic field theory.
Several aspects of this nonrelativistic field theory are studied in the
holographic picture. | hep |
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