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Holographic order parameter for charge fractionalization: Nonlocal order parameters for deconfinement, such as the entanglement entropy
and Wilson loops, depend on spatial surfaces \Sigma. These observables are
given holographically by the area of a certain bulk spatial surface \Gamma,
ending on \Sigma. At finite charge density it is natural to consider the
electric flux through the bulk surface \Gamma, in addition to its area. We show
that this flux provides a refined order parameter that can distinguish
`fractionalized' phases, with charged horizons, from what we term `cohesive'
phases, with charged matter in the bulk. Fractionalization leads to a volume
law for the flux through the surface, the flux for deconfined but cohesive
phases is between a boundary and a volume law, while finite density confined
phases have vanishing flux through the surface. We suggest two possible field
theoretical interpretations for this order parameter. The first is as
information extracted from the large N reduced density matrix associated to
\Sigma. The second is as surface operators dual to polarized bulk `D-branes',
carrying an electric dipole moment. | hep |
What can be measured asymptotically?: We consider asymptotic observables in quantum field theories in which the
S-matrix makes sense. We argue that in addition to scattering amplitudes, a
whole compendium of inclusive observables exists where the time-ordering is
relaxed. These include expectation values of electromagnetic or gravitational
radiation fields as well as out-of-time-order amplitudes. We explain how to
calculate them in two ways: by relating them to amplitudes and products of
amplitudes, and by using a generalization of the LSZ reduction formula. As an
application, we discuss one-loop master integrals contributing to gravitational
radiation in the post-Minkowski expansion, emphasizing the role of classical
cut contributions and highlighting the different infrared physics of in-in
observables. | hep |
Dark matter mass from relic abundance, an extra $U(1)$ gauge boson, and
active-sterile neutrino mixing: In a model with an extra $U(1)$ gauge to SM gauge group, we have shown the
allowed region of masses of extra gauge boson and the dark matter which is the
lightest one among other right-handed Majorana fermions present in the model.
To obtain this region, we have used bounds coming from constraints on
active-sterile neutrino masses and mixing from various oscillation experiments,
constraint on dark matter relic density obtained by PLANCK together with the
constraint on the extra gauge boson mass and its gauge coupling recently
obtained by ATLAS Collaboration at LHC. From the allowed regions, it is
possible to get some lower bounds on the masses of the extra gauge boson and
the dark matter and considering those values it is possible to infer what could
be the spontaneous symmetry breaking scale of an extra $U(1)$ gauge symmetry. | hep |
Are there near-threshold Coulomb-like Baryonia?: The $\Lambda_c(2590) \Sigma_c$ system can exchange a pion near the
mass-shell. Owing to the opposite intrinsic parity of the $\Lambda_c(2590)$ and
$\Sigma_c$, the pion is exchanged in S-wave. This gives rise to a Coulomb-like
force that might be able to bind the system. If one takes into account that the
pion is not exactly on the mass shell, there is a shallow S-wave state, which
we generically call the $Y_{cc}(5045)$ and $Y_{c\bar c}(5045)$ for the
$\Lambda_c(2590) \Sigma_c$ and $\Lambda_c(2590) \bar{\Sigma}_c$ systems
respectively. For the baryon-antibaryon case this Coulomb-like force is
independent of spin: the $Y_{c\bar c}(5045)$ baryonia will appear either in the
spin $S=0$ or $S=1$ configurations with G-parities $G=(-1)^{L+S+1}$. For the
baryon-baryon case the Coulomb-like force is attractive in the spin $S=0$
configuration, for which a doubly charmed molecule is expected to form near the
threshold. This type of spectrum might be very well realized in other molecular
states composed of two opposite parity hadrons with the same spin and a mass
difference close to that of a pseudo-Goldstone boson, of which a few examples
include the $\Lambda(1405) N$, $\Lambda(1520) \Sigma^*$, $\Xi(1690) \Sigma$,
$D_{s0}^*(2317) D$ and $D_{s1}^*(2460) D^*$ molecules. | hep |
Conversion of protons to positrons by a black hole: The conversion of protons to positrons at the horizon of a black hole (BH) is
considered. It is shown that the process may efficiently proceed for BHs with
masses in the range $\sim 10^{18}$ -- $10^{21}$ g. It is argued that the
electric charge of BH acquired by the proton accretion to BH could create
electric field near BH horizon close to the critical Schwinger one. It leads to
efficient electron-positron pair production, when electrons are back captured
by the BH while positrons are emitted into outer space. Annihilation of these
positrons with electrons in the interstellar medium may at least partially
explain the origin of the observed 511 keV line. | hep |
M_b and f_B from non-perturbatively renormalized HQET with Nf=2 light
quarks: We present an updated analysis of the non-perturbatively renormalized b-quark
mass and B meson decay constant based on CLS lattices with two dynamical
non-perturbatively improved Wilson quarks. This update incorporates additional
light quark masses and lattice spacings in large physical volume to improve
chiral extrapolations and to reach the continuum limit. We use Heavy Quark
Effective Theory (HQET) including 1/m_b terms with non-perturbative
coefficients based on the matching of QCD and HQET developed by the ALPHA
collaboration during the past years. | hep |
A Density Matrix Renormalization Group Approach to an Asymptotically
Free Model with Bound States: We apply the DMRG method to the 2 dimensional delta function potential which
is a simple quantum mechanical model with asymptotic freedom and formation of
bound states. The system block and the environment block of the DMRG contain
the low energy and high energy degrees of freedom, respectively. The ground
state energy and the lowest excited states are obtained with very high
accuracy. We compare the DMRG method with the Similarity RG method and propose
its generalization to field theoretical models in high energy physics. | hep |
From Neutrino Masses to Proton Decay: Current theoretical and experimental issues are reviewed in the light of the
recent SuperKamiokande discovery. By using quark-lepton symmetries, derived
from Grand Unification and/or string theories, we show how to determine the
necessary neutrino parameters. In addition, the seesaw neutrino masses set the
scale for the proton decay operators by ``measuring'' the standard model
cut-off. The SuperKamiokande values suggest that proton decay is likely to be
observed early in the XXIst Century. | hep |
Correlation functions of just renormalizable tensorial group field
theory: The melonic approximation: The $D$-colored version of tensor models has been shown to admit a large
$N$-limit expansion. The leading contributions result from so-called melonic
graphs which are dual to the $D$-sphere. This is a note about the
Schwinger-Dyson equations of the tensorial $\varphi^{4}_{5}$-model (with
propagator $1/{\bf p}^{2}$) and their melonic approximation. We derive the
master equations for two- and four-point correlation functions and discuss
their solution. | hep |
Extra U(1) as natural source of a monochromatic gamma ray line: Extensions of the Standard Model with an extra U'(1) abelian group
generically generate terms coming from loops of heavy fermions, leading to
three gauge boson couplings, in particular Z'Z gamma. We show that WMAP data
constrains the gauge coupling of the group g_D to values comparable with the
electro-weak ones, rather independently of the mass of Z'. Moreover, the model
predicts a monochromatic gamma-ray line which can fit a 130 GeV signal at the
FERMI telescope for natural values of the Chern-Simons terms and a dark matter
mass around 144.5 GeV. | hep |
On the $p^4$--corrections to $K \to 3π$ decay amplitudes in nonlinear
and linear chiral models: The calculations of isotopic amplitudes and their results for the direct
$CP$--violating charge asymmetry in $K^\pm \to 3\pi$ decays within the
nonlinear and linear ($\sigma$--model) chiral Lagrangian approach are compared
with each other. It is shown, that the latter, taking into account intermediate
scalar resonances, does not reproduce the $p^4$--corrections of the nonlinear
approach introduced by Gasser and Leutwyler, being saturated mainly by vector
resonance exchange. The resulting differences concerning the $CP$ violation
effect are traced in some detail. | hep |
Holographic entanglement entropy for massive flavours in dS_4: We examine the holographic entanglement entropy of spherical regions in de
Sitter space in the presence of massive flavour fields which are modelled by
probe D7 branes in AdS_5xS^5. We focus on the finite part of the massive
correction to the entropy in the limits of small mass and large mass that are
separated by a phase transition between two topologically distinct brane
embeddings. For small masses, it approaches the flat space result for small
spheres, whereas for large spheres there is a term that goes as the log of the
sphere radius. For large masses, we find evidence for a universal contribution
logarithmic in the mass. In all cases the entanglement entropy is smooth as the
sphere radius crosses the horizon. | hep |
Entropy of near-extremal dyonic black holes: In this note it is shown that near-extremal four dimensional dyonic black
holes, where the dilaton is not constant, can be described by a microscopic
model consisting of a one-dimensional gas of massless particles. | hep |
The Width Difference of $B_d$ Mesons: We estimate $\dg/\Gamma_d$, including $1/m_b$ contributions and part of the
next-to-leading order QCD corrections. We find that adding the latter
corrections decreases the value of $\dg/\Gamma_d$ computed at the leading order
by a factor of almost 2. We also show that under certain conditions an upper
bound on the value of $\dg/\Gamma_d$ in the presence of new physics can be
derived. With the high statistics and accurate time resolution of the upcoming
LHC experiment, the measurement of $\dg$ seems to be possible. This measurement
would be important for an accurate measurement of $\sin(2\beta)$ at the LHC. In
addition, we point out the possibility that the measurement of the width
difference leads to a clear signal for new physics. | hep |
Reconciling sterile neutrinos with big bang nucleosynthesis: We re-examine the big bang nucleosynthesis (BBN) bounds on the mixing of
neutrinos with sterile species. These bounds depend on the assumption that the
relic neutrino asymmetry $L_{\nu}$ is very small. We show that for $L_{\nu}$
large enough (greater than about $10^{-5}$) the standard BBN bounds do not
apply. We apply this result to the sterile neutrino solution to the atmospheric
neutrino anomaly and show that for $L_{\nu} > 7 \times 10^{-5}$ it is
consistent with BBN. The BBN bounds on sterile neutrinos mixing with electron
neutrinos can also be weakened considerably. | hep |
The c=1 String Theory S-Matrix Revisited: We revisit the perturbative S-matrix of c=1 string theory from the worldsheet
perspective. We clarify the origin of the leg pole factors, the non-analyticity
of the string amplitudes, and the validity as well as limitations of earlier
computations based on resonance momenta. We compute the tree level 4-point
amplitude and the genus one 2-point reflection amplitude by numerically
integrating Virasoro conformal blocks with DOZZ structure constants on the
sphere and on the torus, with sufficiently generic complex Liouville momenta,
and find agreement with known answers from the c=1 matrix model. | hep |
A Note on Large N Thermal Free Energy in Supersymmetric Chern-Simons
Vector Models: We compute the exact effective action for \cN=3 U(N)_k and \cN=4,6
U(N)_k\times U(N')_{-k} Chern-Simons theories with minimal matter content in
the 't Hooft vector model limit under which N and k go to infinity holding N/k,
N' fixed. We also extend this calculation to \cN=4,6 mass deformed case. We
show those large N effective actions except mass-deformed \cN=6 case precisely
reduce to that of \cN=2 U(N)_k Chern-Simons theory with one fundamental chiral
field up to overall multiple factor. By using this result we argue the thermal
free energy and self-duality of the \cN=3,4,6 Chern-Simons theories including
the \cN=4 mass term reduce to those of the \cN=2 case under the limit. | hep |
The branching fraction and effective lifetime of $B_{(s)}^{0}
\rightarrow μ^+ μ^-$ at LHCb with Run 1 and Run 2 data: After Run 1 of the LHC, global fits to $b \rightarrow s \ell \ell$
observables show a deviation from the Standard Model (SM) with a significance
of $\sim$ 4 standard devations. An example of a $b \rightarrow s \ell \ell$
process is the decay of a $B_{s}^0$ meson into two muons ($B_{s}^0 \rightarrow
\mu^+ \mu^-$). The latest analysis of $B_{(s)}^0 \rightarrow \mu^+ \mu^-$
decays by LHCb with Run 1 and Run 2 data is presented. The $B_{s}^0 \rightarrow
\mu^+ \mu^-$ decay is observed for the first time by a single experiment. In
addition, the first measurement of the $B_{s}^0 \rightarrow \mu^+ \mu^-$
effective lifetime is performed. No significant excess of $B^0 \rightarrow
\mu^+ \mu^-$ decays is observed. All results are consistent with the SM and
constrain New Physics in $b \rightarrow s \ell \ell$ processes. | hep |
Three symmetry breakings in strong and radiative decays of strange heavy
mesons: In this paper, we investigate three symmetry breaking effects in strong and
radiative decays of strange heavy mesons. We study 1/m_Q corrections within the
heavy quark effect theory, as well as SU(3) and SU(2) symmetry breakings
induced by light quark mass differences and the \eta-\pi mixing vertex. These
effects are studied in a covariant model. The numerical results show that the
1/m_Q corrections of the coupling constants are consistent with \alpha_s
\Lambda_{QCD}/m_Q. The SU(3) symmetry violating effect of the strong coupling
constant is obviously larger than that of the magnetic coupling constant. The
value of the \eta-\pi mixing vertex has some changes because of the renewed
data. As compared with the other theoretical calculations and the experimental
data, our radiative decay rates are much larger than those of the other
theoretical methods, except for \chiPT; however, our branching ratios are close
to the experimental data. | hep |
Saturation of $E_T/N_{ch}$ and Freeze-Out Criteria in Heavy-Ion
Collisions: The pseudorapidity densities of transverse energy, the charged particle
multiplicity and their ratios, $E_T/N_{ch}$, are estimated at mid-rapidity, in
a statistical-thermal model based on chemical freeze-out criteria, for a wide
range of energies from GSI-AGS-SPS to RHIC. It has been observed that in
nucleus-nucleus collisions, $E_T/N_{ch}$ increases rapidly with beam energy and
remains approximately constant at about a value of 800 MeV for beam energies
from SPS to RHIC. $E_T/N_{ch}$ has been observed to be almost independent of
centrality at all measured energies. The statistical-thermal model describes
the energy dependence as well as the centrality independence, qualitatively
well. The values of $E_T/N_{ch}$ are related to the chemical freeze-out
criterium, $E/N \approx 1 GeV$ valid for primordial hadrons. We have studied
the variation of the average mass $(<MASS>), N_{decays}/N_{primordial},
N_{ch}/N_{decays}$ and $E_T/N_{ch}$ with $\sqrt{s_{NN}}$ for all freeze-out
criteria discussed in literature. These observables show saturation around SPS
and higher $\sqrt{s_{NN}}$, like the chemical freeze-out temperature
($T_{ch}$). | hep |
A non-chiral extension of the standard model with mirror fermions: The difficulties of defining chiral gauge theories non-perturbatively suggest
a vector-like extension of the standard model with three mirror fermion
families. Some phenomenological implications of such an extension are
discussed. | hep |
Kac-Moody Symmetry in Hosotani Model: The symmetry of the massive tower of fields in higher-dimensional Yang-Mills
theory compactified on a space-time of the form M_d x S^1 is clarified. The
transformations form a loop algebra, a class of Kac-Moody algebras. Since the
symmetry is spontaneously broken, vector fields "eat" Goldstone bosons and
acquire masses. The field of zero-mass mode can also become massive provided
that the field of the internal component develops a vacuum expectation value.
The relation between the "restoration" of the symmetry in massive modes and the
gauge transformation of the zero-mode vacuum field is discussed. | hep |
A gauge invariant infrared stabilization of 3D Yang-Mills gauge theories: We demonstrate that the inversion method can be a very useful tool in
providing an infrared stabilization of 3D gauge theories, in combination with
the mass operator $A^2$ in the Landau gauge. The numerical results will be
unambiguous, since the corresponding theory is ultraviolet finite in
dimensional regularization, making a renormalization scale or scheme obsolete.
The proposed framework is argued to be gauge invariant, by showing that the
nonlocal gauge invariant operator $A^2_{\min}$, which reduces to $A^2$ in the
Landau gauge, could be treated in 3D, in the sense that it is power counting
renormalizable in any gauge. As a corollary of our analysis, we are able to
identify a whole set of powercounting renormalizable nonlocal operators of
dimension two. | hep |
Soft Pomeron in Holographic QCD: We study the graviton Regge trajectory in Holographic QCD as a model for high
energy scattering processes dominated by soft pomeron exchange. This is done by
considering spin J fields from the closed string sector that are dual to
glueball states of even spin and parity. In particular, we construct a model
that governs the analytic continuation of the spin J field equation to the
region of real J < 2, which includes the scattering domain of negative
Maldelstam variable t. The model leads to approximately linear Regge
trajectories and is compatible with the measured values of 1.08 for the
intercept and 0.25 GeV$^{-2}$ for the slope of the soft pomeron. The intercept
of the secondary pomeron trajectory is in the same region of the subleading
trajectories, made of mesons, proposed by Donnachie and Landshoff, and should
therefore be taken into account. | hep |
Modular Invariant Regularization of String Determinants and the Serre
GAGA Principle: Since any string theory involves a path integration on the world-sheet
metric, their partition functions are volume forms on the moduli space of genus
g Riemann surfaces M_g, or on its super analog. It is well known that modular
invariance fixes strong constraints that in some cases appear only at higher
genus. Here we classify all the Weyl and modular invariant partition functions
given by the path integral on the world-sheet metric, together with space-time
coordinates, b-c and/or beta-gamma systems, that correspond to volume forms on
M_g. This was a long standing question, advocated by Belavin and Knizhnik,
inspired by the Serre GAGA principle and based on the properties of the Mumford
forms. The key observation is that the Bergman reproducing kernel provides a
Weyl and modular invariant way to remove the point dependence that appears in
the above string determinants, a property that should have its superanalog
based on the super Bergman reproducing kernel. This is strictly related to the
properties of the propagator associated to the space-time coordinates. Such
partition functions Z[J] have well-defined asymptotic behavior and can be
considered as a basis to represent a wide class of string theories. In
particular, since non-critical bosonic string partition functions Z_D are
volume forms on M_g, we suggest that there is a mapping, based on bosonization
and degeneration techniques, from the Liouville sector to first order systems
that may identify Z_D as a subclass of the Z[J]. The appearance of b-c and
beta-gamma systems of any conformal weight shows that such theories are related
to W algebras. The fact that in a large N 't Hooft-like limit 2D W_N minimal
models CFTs are related to higher spin gravitational theories on AdS_3,
suggests that the string partition functions introduced here may lead to a
formulation of higher spin theories in a string context. | hep |
No Mirror Symmetry in Landau-Ginzburg Spectra!: We use a recent classification of non-degenerate quasihomogeneous polynomials
to construct all Landau-Ginzburg (LG) potentials for N=2 superconformal field
theories with c=9 and calculate the corresponding Hodge numbers. Surprisingly,
the resulting spectra are less symmetric than the existing incomplete results.
It turns out that models belonging to the large class for which an explicit
construction of a mirror model as an orbifold is known show remarkable mirror
symmetry. On the other hand, half of the remaining 15\% of all models have no
mirror partners. This lack of mirror symmetry may point beyond the class of
LG-orbifolds. | hep |
Exponential BPS graphs and D-brane counting on toric Calabi-Yau
threefolds: Part II: We study BPS states of 5d $\mathcal{N}=1$ $SU(2)$ Yang-Mills theory on
$S^1\times \mathbb{R}^4$. Geometric engineering relates these to enumerative
invariants for the local Hirzebruch surface $\mathbb{F}_0$. We illustrate
computations of Vafa-Witten invariants via exponential networks, verifying
fiber-base symmetry of the spectrum at certain points in moduli space, and
matching with mirror descriptions based on quivers and exceptional collections.
Albeit infinite, parts of the spectrum organize in families described by simple
algebraic equations. Varying the radius of the M-theory circle interpolates
smoothly with the spectrum of 4d $\mathcal{N}=2$ Seiberg-Witten theory,
recovering spectral networks in the limit. | hep |
Search for the standard model Higgs boson decaying to a W pair in the
fully leptonic final state in pp collisions at sqrt(s) = 7 TeV: A search for the standard model Higgs boson decaying to W+W- in pp collisions
at sqrt(s) = 7 TeV is reported. The data are collected at the LHC with the CMS
detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns.
The W+W- candidates are selected in events with two charged leptons and large
missing transverse energy. No significant excess of events above the standard
model background expectations is observed, and upper limits on the Higgs boson
production relative to the standard model Higgs expectation are derived. The
standard model Higgs boson is excluded in the mass range 129-270 GeV at 95%
confidence level. | hep |
New Class of Quark Mass Matrices and the Flavor Mixing Matrix: We discuss a new general class of mass matrix ansatz that respects the
fermion mass hierarchy and calculability of the flavor mixing matrix. This is a
generalization of the various specific forms of the mass matrix that is
obtained by successive breaking of the maximal permutation symmetry. By
confronting the experimental data, a large class of the mass matrices are shown
to survive, while certain specific cases are phenomenologically ruled out. | hep |
Finite Grand Unified Theories and Inflation: A class of finite GUTs in curved spacetime is considered in connection with
the cosmological inflation scenario. It is confirmed that the use of the
running scalar-gravitational coupling constant in these models helps realizing
a successful chaotic inflation. The analyses are made for some different sets
of the models. | hep |
O(2)-scaling in finite and infinite volume: The exact nature of the chiral phase transition in QCD is still under
investigation. In $N_f=2$ and $N_f=(2+1)$ lattice simulations with staggered
fermions the expected O($N$)-scaling behavior was observed. However, it is
still not clear whether this behavior falls into the O(2) or O(4) universality
class. To resolve this issue, a careful scaling and finite-size scaling
analysis of the lattice results is needed. We use a functional renormalization
group to perform a new investigation of the finite-size scaling regions in
O(2)- and O(4)-models. We also investigate the behavior of the critical
fluctuations by means of the $4^{\text{th}}$-order Binder cumulant. The
finite-size analysis of this quantity provides an additional way for
determining the universality class of the chiral phase transition in lattice
QCD. | hep |
A quantum field model for tachyonic neutrinos with Lorentz symmetry
breaking: A quantum field model for Dirac-like tachyons respecting a frame-dependent
interpretation rule, and thus inherently breaking Lorentz invariance, is
defined. It is shown how the usual paradoxa ascribed to tachyons, instability
and acausality, are resolved in this model, and it is argued elsewhere that
Lorentz symmetry breaking is necessary to permit perturbative renormalizability
and causality. Elimination of negative-normed states results in only
left-handed particles and right-handed antiparticles, suitable for describing
the neutrino. In this context the neutron beta decay spectrum is calculated
near the end point for large, but not ultrarelativistic preferred frame speed,
assuming a vector weak interaction vertex. | hep |
Decay constants of the pion and its excitations on the lattice: We present a calculation using lattice QCD of the ratios of decay constants
of the excited states of the pion, to that of the pion ground state, at three
values of the pion mass between 400 and 700 MeV, using an anisotropic clover
fermion action with three flavors of quarks. We find that the decay constant of
the first excitation, and more notably of the second, is suppressed with
respect to that of the ground-state pion, but that the suppression shows little
dependence on the quark mass. The strong suppression of the decay constant of
the second excited state is consistent with its interpretation as a
predominantly hybrid state. | hep |
Baryonic content of the pion: The baryon form factor of charged pions arises since isospin symmetry is
broken with unequal up and down quark masses, $m_d>m_u$, as well as
electromagnetic effects. We obtain estimates for this basic property in two
phenomenological ways: from simple constituent quark models, as well as from
fitting the $e^+e^- \to \pi^+ \pi^-$ data. All our methods yield the result
that the baryon mean square radius, extracted from the slope of the form
factor, is positive for $\pi^+$, hence a picture where the outer region has a
net baryon, and the inner region a net antibaryon density, both compensating
each other such that the total baryon number is zero. For $\pi^-$ the effect is
equal and opposite. We estimate the corresponding mean squared baryon radius as
$\langle r^2 \rangle_B^{\pi^{+}} = (0.03-0.04~{\rm fm})^2$. | hep |
Matrix models for classical groups and Toeplitz$\pm $Hankel minors with
applications to Chern-Simons theory and fermionic models: We study matrix integration over the classical Lie groups $U(N),Sp(2N),O(2N)$
and $O(2N+1)$, using symmetric function theory and the equivalent formulation
in terms of determinants and minors of Toeplitz$\pm$Hankel matrices. We
establish a number of factorizations and expansions for such integrals, also
with insertions of irreducible characters. As a specific example, we compute
both at finite and large $N$ the partition functions, Wilson loops and Hopf
links of Chern-Simons theory on $S^{3}$ with the aforementioned symmetry
groups. The identities found for the general models translate in this context
to relations between observables of the theory. Finally, we use character
expansions to evaluate averages in random matrix ensembles of Chern-Simons
type, describing the spectra of solvable fermionic models with matrix degrees
of freedom. | hep |
Phase transition and hyperscaling violation for scalar Black Branes: We investigate the thermodynamical behavior and the scaling symmetries of the
scalar dressed black brane (BB) solutions of a recently proposed, exactly
integrable Einstein-scalar gravity model [1], which also arises as
compactification of (p-1)-branes with a smeared charge. The extremal, zero
temperature, solution is a scalar soliton interpolating between a conformal
invariant AdS vacuum in the near-horizon region and a scale covariant metric
(generating hyperscaling violation on the boundary field theory)
asymptotically. We show explicitly that for the boundary field theory this
implies the emergence of an UV length scale (related to the size of the brane),
which decouples in the IR, where conformal invariance is restored. We also show
that at high temperatures the system undergoes a phase transition. Whereas at
small temperature the Schwarzschild-AdS BB is stable, above a critical
temperature the scale covariant, scalar-dressed BB solution, becomes
energetically preferred. We calculate the critical exponent z and the
hyperscaling violation parameter of the scalar-dressed phase. In particular we
show that the hyperscaling violation parameter is always negative. We also show
that the above features are not a peculiarity of the exact integrable model of
Ref.[1], but are a quite generic feature of Einstein-scalar and
Einstein-Maxwell-scalar gravity models for which the squared-mass of the scalar
field is positive and the potential vanishes exponentially as the scalar field
goes to minus infinity. | hep |
Optimizing Distillation for charmonium and glueballs: We study the charmonium spectrum on an ensemble with two heavy dynamical
quarks with a mass at half the physical charm quark mass. Operators for
different quantum numbers are used in the framework of distillation with
different smearing profiles to increase the overlap with ground and excited
states. The use of exact distillation, large statistics and the absence of
light quarks gives robust results for the charmonium spectrum. We also present
preliminary results for the glueball spectrum in this theory. | hep |
D-branes on Calabi-Yau Manifolds and Superpotentials: We show how to compute terms in an expansion of the world-volume
superpotential for fairly general D-branes on the quintic Calabi-Yau using
linear sigma model techniques, and show in examples that this superpotential
captures the geometry and obstruction theory of bundles and sheaves on this
Calabi-Yau. | hep |
Non-unimodular reductions and N = 4 gauged supergravities: We analyze the class of four-dimensional N = 4 supergravities obtained by
gauging the axionic shift and axionic rescaling symmetries. These theories are
formulated with the machinery of embedding tensors and shown to be deducible
from higher dimensions using a Scherk--Schwarz reduction with a twist by a
non-compact symmetry. This allows to evade the usual unimodularity requirement
and completes the dictionary between heterotic gaugings and fluxes, at least
for the "geometric sector". | hep |
Evidence for single top quark production at D0: The results of the first analysis to show evidence for production of single
top quarks are presented. Using 0.9 fb-1 of data collected with the D0 detector
at the Fermilab Tevatron, the analysis is performed in the electron+jets and
muon+jets decay modes, taking special care in modeling the large backgrounds,
applying a new powerful b-quark tagging algorithm and using three multivariate
techniques to extract the small signal in the data. The combined measured
production cross section is 4.8 +- 1.3 pb. The probability to measure a cross
section at this value or higher in the absence of a signal is 0.027%,
corresponding to a 3.5 standard deviation significance. | hep |
Atomic parity violation in the economical 3-3-1 model: The deviation $\de Q_{\mathrm{W}}$ of the weak charge from its standard model
prediction due to the mixing of the $W$ boson with the charged bilepton $Y$ as
well as of the $Z$ boson with the neutral $Z'$ and the real part of the
non-Hermitian neutral bilepton $X$ in the economical 3-3-1 model is
established. Additional contributions to the usual $\de Q_\mathrm{W}$
expression in the extra $\mathrm{U}(1)$ models and the left-right models are
obtained. Our calculations are quite different from previous analyzes in this
kind of the 3-3-1 models and give the limit on mass of the $Z'$ boson, the
$Z-Z'$ and $W-Y$ mixing angles with the more appropriate values: $M_{Z'} > 564\
\mathrm{GeV}, -0.018<\sin \va < 0$ and $|\sin \theta| < 0.043$. | hep |
Improved Sterile Neutrino Constraints from the STEREO Experiment with
179 Days of Reactor-On Data: The STEREO experiment is a very short baseline reactor antineutrino
experiment. It is designed to test the hypothesis of light sterile neutrinos
being the cause of a deficit of the observed antineutrino interaction rate at
short baselines with respect to the predicted rate, known as the reactor
antineutrino anomaly. The STEREO experiment measures the antineutrino energy
spectrum in six identical detector cells covering baselines between 9 and 11 m
from the compact core of the ILL research reactor. In this article, results
from 179 days of reactor turned on and 235 days of reactor turned off are
reported at a high degree of detail. The current results include improvements
in the modelling of detector optical properties and the gamma-cascade after
neutron captures by gadolinium, the treatment of backgrounds, and the
statistical method of the oscillation analysis. Using a direct comparison
between antineutrino spectra of all cells, largely independent of any flux
prediction, we find the data compatible with the null oscillation hypothesis.
The best-fit point of the reactor antineutrino anomaly is rejected at more than
99.9% C.L. | hep |
Strong-Field Breit-Wheeler Pair Production in Short Laser Pulses:
Identifying Multiphoton Interference and Carrier-Envelope-Phase Effects: The creation of electron-positron pairs by the strong-field Breit-Wheeler
process in intense short laser pulses is investigated in the framework of
laser-dressed quantum electrodynamics. Regarding laser field parameters in the
multiphoton regime, special attention is brought to the energy spectrum of the
created particles, which can be reproduced and explained by means of an
intuitive model. The model is based on the probabilities of multiphoton events
driven by the spectral components of the laser pulse. It allows, in particular,
to identify interferences between different pair production channels which
exhibit a characteristic dependence on the laser carrier-envelope phase. | hep |
Aharonov-Bohm phases in a quantum LC circuit: We study novel types of contributions to the partition function of the
Maxwell system defined on a small compact manifold. These contributions, often
not addressed in the perturbative treatment with physical photons, emerge as a
result of tunneling transitions between topologically distinct but physically
identical vacuum winding states. These new terms give an extra contribution to
the Casimir pressure, yet to be measured. We argue that this effect is highly
sensitive to a small external electric field, which should be contrasted with
the conventional Casimir effect where the vacuum photons are essentially
unaffected by any external field. Furthermore, photons will be emitted from the
vacuum in response to a time-dependent electric field, similar to the dynamical
Casimir effect in which real particles are radiated from the vacuum due to the
time-dependent boundary conditions. We also propose an experimental setup using
a quantum LC circuit to detect this novel effect. We expect physical electric
charges to appear on the capacitor plates when the system dimension is such
that coherent Aharonov-Bohm phases can be maintained over macroscopically large
distances. | hep |
Dielectric correction to the Chiral Magnetic Effect: We derive an electric current density $j_{em}$ in the presence of a magnetic
field $B$ and a chiral chemical potential $\mu_5$. We show that $j_{em}$ has
not only the anomaly-induced term $\propto \mu_5 B$ (i.e. Chiral Magnetic
Effect) but also a non-anomalous correction which comes from interaction
effects and expressed in terms of the susceptibility. We find the correction
characteristically dependent on the number of quark flavors. The numerically
estimated correction turns out to be a minor effect on heavy-ion collisions but
can be tested by the lattice QCD simulation. | hep |
Finite Volume Phases of Large N Gauge Theories with Massive Adjoint
Fermions: The phase structure of QCD-like gauge theories with fermions in various
representations is an interesting but generally analytically intractable
problem. One way to ensure weak coupling is to define the theory in a small
finite volume, in this case S^3 x S^1. Genuine phase transitions can then occur
in the large N theory. Here, we use this technique to investigate SU(N) gauge
theory with a number N_f of massive adjoint-valued Majorana fermions having
non-thermal boundary conditions around S^1. For N_f =1 we find a line of
transitions that separate the weak-coupling analogues of the confined and
de-confined phases for which the density of eigenvalues of the Wilson line
transform from the uniform distribution to a gapped distribution. However, the
situation for N_f >1 is much richer and a series of weak-coupling analogues of
partially-confined phases appear which leave unbroken a Z_p subgroup of the
centre symmetry. In these Z_p phases the eigenvalue density has p gaps and they
are separated from the confining phase and from one-another by first order
phase transitions. We show that for small enough mR (the mass of the fermions
times the radius of the S^3) only the confined phase exists. The large N phase
diagram is consistent with the finite N result and with other approaches based
on R^3 x S^1 calculations and lattice simulations. | hep |
Energy Loss of a Heavy Particle near 3D Charged Rotating Hairy Black
Hole: In this paper we consider charged rotating black hole in 3 dimensions with an
scalar charge and discuss about energy loss of heavy particle moving near the
black hole horizon. We also study quasi-normal modes and find dispersion
relations. We find that the effect of scalar charge and electric charge is
increasing energy loss. | hep |
Entanglement Renyi Entropies in Conformal Field Theories and Holography: An entanglement Renyi entropy for a spatial partition of a system is studied
in conformal theories which admit a dual description in terms of an anti-de
Sitter gravity. The divergent part of the Renyi entropy is computed in 4D
conformal N=4 super Yang-Mills theory at a weak coupling. This result is used
to suggest a holographic formula which reproduces the Renyi entropy at least in
the leading approximation. The holographic Renyi entropy is an invariant
functional set on a codimension 2 minimal hypersurface in the bulk geometry.
The bulk space does not depend on order $n$ of the Renyi entropy. The
holographic Renyi entropy is a sum of local and non-local functionals
multiplied by polynomials of $1/n$. | hep |
Exotica and discreteness in the classification of string spectra: I discuss the existence of discrete properties in the landscape of free
fermionic heterotic-string vacua that were discovered via their classification
by SO(10) GUT models and its subgroups such as the Pati-Salam, Flipped SU(5)
and SU(4) x SU(2) x U(1) models. The classification is carried out by fixing a
set of basis vectors and varying the GGSO projection coefficients entering the
one-loop partition function. The analysis of the models is facilitated by
deriving algebraic expressions for the GSO projections that enable a
computerised analysis of the entire string spectrum and the scanning of large
spaces of vacua. The analysis reveals discrete symmetries like the
spinor-vector duality observed at the SO(10) level and the existence of
exophobic Pati-Salam vacua. Contrary to the Pati-Salam case the classification
shows that there are no exophobic Flipped SU(5) vacua with an odd number of
generations. It is observed that the SU(4) x SU(2) x U(1) models are
substantially more constrained. | hep |
Implications of recent MINER$ν$A results for neutrino energy
reconstruction: Among the most important tasks of neutrino oscillation experiments is
correctly estimating the parent neutrino energy from the by-products of their
interactions. Large uncertainties in our current understanding of such
processes can significantly hamper this effort. We explore several recent
measurements made using the \mnv{} detector in the few-GeV NuMI muon neutrino
beam at Fermilab: the differential cross-section vs. $Q^2$ for charged-current
quasi-elastic scattering, the differential cross-sections vs. pion angle and
pion kinetic energy for resonant single charged pion production, and the
differential cross-sections vs. pion angle and kinetic energy for coherent pion
production. We furthermore discuss their implications for energy reconstruction
in oscillation measurements. | hep |
Fuzzy de Sitter Space: We discuss properties of fuzzy de Sitter space defined by means of algebra of
the de Sitter group $\mathrm{SO}(1,4)$ in unitary irreducible representations.
It was shown before that this fuzzy space has local frames with metrics that
reduce, in the commutative limit, to the de Sitter metric. Here we determine
spectra of the embedding coordinates for $(\rho,s=\frac 12)$ unitary
irreducible representations of the principal continuous series of the
$\mathrm{SO}(1,4)$. The result is obtained in the Hilbert space representation,
but using representation theory it can be generalized to all representations of
the principal continuous series. | hep |
On Skyrmion semiclassical quantization in the presence of an isospin
chemical potential: The semiclassical description of Skyrmions at small isospin chemical
potential $\mu_I$ is carefully analyzed. We show that when the calculation of
the energy of a nucleon is performed using the straightforward generalization
of the vacuum sector techniques ($\mu_I=0$), together with the "natural"
assumption $\mu_I = {\cal O} (N_c^0)$, the proton and neutron masses are
nonlinear in $\mu_I$ in the regime $|\mu_I| < m_\pi$. Although these
nonlinearities turn out to be numerically quite small, such a result fails to
strictly agree with the very robust prediction that for those values of $\mui$
the energy excitations above the vacuum are linear in $\mu_I$. The resolution
of this paradox is achieved by studying the realization of the large $N_c$
limit of $QCD$ in the Skyrme model at finite $\mui$. This is done in a
simplified context devoid of the technical complications present in the Skyrme
model but which fully displays the general scaling behavior with $N_c$. The
analysis shows that the paradoxical result appears as a symptom of using the
semi-classical approach beyond its regime of validity and that, at a formal
level, the standard methods for dealing with the Skyrme model are only strictly
justified for states of high isospin $I \sim N_c$. | hep |
Euclidean quantum gravity and stochastic approach: Physical reality of
complex-valued instantons: In this talk, we compare two states: the stationary state in stochastic
inflation and the ground state wave function of the universe. We already know
that, for the potential with a static field, two pictures give the same
probability distribution. Here, we go beyond this limit and assert that two
pictures indeed have deeper relations. We illustrate a simple example so that
there is a corresponding instanton if a certain field value has a non-zero
probability in the statistical side. This instanton should be complex-valued.
Furthermore, the compact manifold in the Euclidean side can be interpreted as a
coarse-graining grid size in the stochastic universe. Finally, we summarize the
recent status and possible applications. | hep |
Finite Temperature QED: Non-Cancellation of Infrared Divergencies and
Thermal Corrections to the Electron Magnetic Moment: In this work quantum electrodynamics at T > 0 is considered. For this purpose
we use thermo field dynamics and the causal approach to quantum field theory
according to Epstein and Glaser, the latter being a rigorous method to avoid
the well-known ultraviolet divergencies of quantum field theory. It will be
shown that the theory is infrared divergent if the usual scattering states are
used. The same is true if we use more general mixed states. This is in
contradiction to the results established in the literature, and we will point
out why these earlier approaches fail to describe the infrared behaviour
correctly. We also calculate the thermal corrections to the electron magnetic
moment in the low temperature approximation k_B T << m_e. This is done by
investigating the scattering of an electron on a C-number potential in third
order in the limit of small momentum transfer p -> q. We reproduce one of the
different results reported up to now in literature. In the low temperature
approximation infrared finiteness is recovered in a very straightforward way:
In contrast to the literature we do not have to introduce a thermal Dirac
equation or thermal spinors. | hep |
The AdS(4) x CP(3) string and its Bethe equations in the near plane wave
limit: We perform a detailed study of bosonic type IIA string theory in a large
light-cone momentum / near plane wave limit of $AdS_4 \times CP_3$. In order to
attain this we derive the Hamiltonian up to cubic and quartic order in number
of fields and calculate the energies for string excitations in a $R\times S^2
\times S^2$ subspace. The computation for the string energies is performed for
arbitrary length excitations utilizing an unitary transformation which allows
us to remove the cubic terms in the Hamiltonian. We then rewrite a recent set
of proposed all loop Bethe equations in a light-cone language and compare their
predictions with the obtained string energies. We find perfect agreement. | hep |
Inverse Magnetic Catalysis in hot quark matter within (P)NJL models: Apart from Magnetic Catalysis at low temperatures, recent LQCD studies have
shown the opposite effect at temperatures near the transition region: instead
of enhancing, the magnetic field suppresses the quark condensates (Inverse
Magnetic Catalysis). In this paper, two approaches are discussed within
NJL-type models with Polyakov Loop that reproduce both effects. | hep |
Note on the conjectured breakdown of QED perturbation theory in strong
fields: Strong background fields require a non-perturbative treatment, which is
afforded in QED by the Furry expansion of scattering amplitudes. It has been
conjectured that this expansion breaks down for sufficiently strong fields,
based on the asymptotic growth of loop corrections with increasing "quantum
nonlinearity", essentially the product of field strength and particle energy.
However, calculations to date have assumed that the background is constant. We
show here, using general plane waves of finite duration, that observables at
high quantum nonlinearity scale differently depending on whether intensity or
energy is large. We find that, at high energy, loop contributions to
observables tend to fall with increasing quantum nonlinearity, rather than
grow. | hep |
Symplectic Fermions: We study two-dimensional conformal field theories generated from a
``symplectic fermion'' - a free two-component fermion field of spin one - and
construct the maximal local supersymmetric conformal field theory generated
from it. This theory has central charge c=-2 and provides the simplest example
of a theory with logarithmic operators.
Twisted states with respect to the global SL(2,C)-symmetry of the symplectic
fermions are introduced and we describe in detail how one obtains a consistent
set of twisted amplitudes. We study orbifold models with respect to finite
subgroups of SL(2,C) and obtain their modular invariant partition functions. In
the case of the cyclic orbifolds explicit expressions are given for all two-,
three- and four-point functions of the fundamental fields. The C_2-orbifold is
shown to be isomorphic to the bosonic local logarithmic conformal field theory
of the triplet algebra encountered previously. We discuss the relation of the
C_4-orbifold to critical dense polymers. | hep |
On the W-gravity spectrum and its G-structure: We present results for the BRST cohomology of $\cW[\bfg]$ minimal models
coupled to $\cW[\bfg]$ gravity, as well as scalar fields coupled to $\cW[\bfg]$
gravity. In the latter case we explore an intricate relation to the (twisted)
$\bfg$ cohomology of a product of two twisted Fock modules. | hep |
The Flavor and Spin Structure of Hyperons from Quark Fragmentation: We systematically study the hadron longitudinal polarizations of the octet
baryons at large $z$ from quark fragmentations in $e^+e^-$-annihilation,
polarized charged lepton deep inelastic scattering (DIS) process, and neutrino
(antineutrino) DIS process, based on predictions of quark distributions for the
octet baryons in the SU(6) quark-spectator-diquark model and a perturbative QCD
based counting rule analysis. We show that the $e^+e^-$-annihilation and
polarized charged lepton DIS process are able to distinguish between the two
different predictions of the hyperon polarizations. We also find that the
neutrino/antineutrino DIS process is ideal in order to study both the valence
content of the hyperons and the antiquark to hyperon (quark to anti-hyperon)
fragmentations, which might be related to the sea content of hyperons. | hep |
Measurements of CKM angle $φ_3$ at BELLE: We report recent results on $\phi_3$ measurement at the Belle collaboration.
The analyses reported here are based on a large data sample that contains 657
million $B\bar{B}$ pairs collected with the Belle detector at the KEKB
asymmetric-energy $e^+ e^-$ collider at the $\Upsilon(4S)$ resonance. | hep |
The role of zero-mode contributions in the matching for the twist-3 PDFs
$e(x)$ and $h_{L}(x)$: The perturbative procedure of matching was proposed to connect parton
quasi-distributions that are calculable in lattice QCD to the corresponding
light-cone distributions which enter physical processes. Such a matching
procedure has so far been limited to the twist-2 distributions. Recently, we
addressed the matching for the twist-3 PDF $g_T(x)$. In this work, we extend
our perturbative calculations to the remaining twist-3 PDFs, $e(x)$ and
$h_{L}(x)$. In particular, we discuss the non-trivialities involved in the
calculation of the singular zero-mode contributions for the quasi-PDFs. | hep |
Extended chiral Group and Scalar Diquarks: We introduce extended chiral transformation, which depends both on
pseudoscalar and diquark fields as parameters and determine its group
structure. Assuming soft symmetry breaking in diquark sector, bosonisation of a
quasi-Goldstone $ud$-diquark is performed. In the chiral limit the $ud$-diquark
mass is defined by the gluon condensate, $m_{ud}\approx 300 MeV$. The diquark
charge radius is $<r^2_{ud}>^{1/2}\approx 0.5 fm$. We consider also the flavour
triplet of scalar diquarks $(ud)$, $(us)$ and $(ds)$ together with pseudoscalar
mesons and calculate diquark masses and decay constants in terms of meson
parameters and the gluon condensate. | hep |
Study of the strong $Σ_c\to Λ_c π$, $Σ_c^{*}\to
Λ_c π$ and $Ξ_c^{*}\to Ξ_c π$ decays in a nonrelativistic quark
model: We present results for the strong widths corresponding to the $\Sigma_c\to
\Lambda_c \pi$, $\Sigma_c^{*}\to \Lambda_c \pi$ and $\Xi_c^{*}\to \Xi_c \pi$
decays. The calculations have been done in a nonrelativistic constituent quark
model with wave functions that take advantage of the constraints imposed by
heavy quark symmetry. Partial conservation of axial current hypothesis allows
us to determine the strong vertices from an analysis of the axial current
matrix elements. Our results \hbox{$\Gamma(\Sigma_c^{++}\to \Lambda_c^+
\pi^+)=2.41 \pm0.07\pm0.02 \mathrm{MeV}$}, {$\Gamma(\Sigma_c^{+}\to \Lambda_c^+
\pi^0)=2.79 \pm0.08\pm0.02 \mathrm{MeV}$}, {$\Gamma(\Sigma_c^{0}\to \Lambda_c^+
\pi^-)=2.37 \pm0.07\pm0.02 \mathrm{MeV}$}, {$\Gamma(\Sigma_c^{* ++}\to
\Lambda_c^+ \pi^+)=17.52\pm0.74\pm0.12 \mathrm{MeV}$}, {$\Gamma(\Sigma_c^{*
+}\to \Lambda_c^+ \pi^0)=17.31\pm0.73\pm0.12 \mathrm{MeV}$},
{$\Gamma(\Sigma_c^{* 0}\to \Lambda_c^+ \pi^-)=16.90\pm0.71\pm0.12
\mathrm{MeV}$}, {$\Gamma(\Xi_c^{* +}\to \Xi_c^0
\pi^++\Xi_c^+\pi^0)=3.18\pm0.10\pm0.01 \mathrm{MeV}$} and {$\Gamma(\Xi_c^{*
0}\to \Xi_c^+ \pi^-+\Xi_c^0\pi^0)=3.03\pm0.10\pm0.01 \mathrm{MeV}$} are in good
agreement with experimental determinations. | hep |
Cosmology for Particle Physicists: In these notes we present a selection of topics, each section approximately
amounting to one lecture. We begin with a brief recapitulation of General
Relativity, and the Standard Model of Cosmology. This is followed by lectures
on important signatures of the remote past. These include : (i) inflation, (ii)
density perturbations leading to galaxy formation, (iii) study of hot and cold
relics decoupled from the remaining constituents, some of which can be
candidates for Dark Matter, (iv) baryon asymmetry of the Universe. | hep |
Variable Flavor Number Scheme for Final State Jets in Thrust: We present results for mass effects coming from secondary radiation of heavy
quark pairs related to gluon splitting in the thrust distribution for e+e-
collisions. The results are given in the dijet limit where the hard interaction
scale and the scales related to collinear and soft radiation are widely
separated. We account for the corresponding fixed-order corrections at
O(alpha_s^2) and the summation of all logarithmic terms related to the hard,
collinear and soft scales as well as the quark mass at N3LL order. We also
remove the O(Lambda_QCD) renormalon in the partonic soft function leading to an
infrared evolution equation with a matching condition related to the massive
quark threshold. The quark mass can be arbitrary, ranging from the infinitely
heavy case, where decoupling takes place, down to the massless limit where the
results smoothly merge into the well known predictions for massless quarks. Our
results are formulated in the framework of factorization theorems for e+e-
dijet production and provide universal threshold corrections for the
renormalization group evolution of the hard current, the jet and soft functions
at the scale where the massive quarks are integrated out. The results represent
a first explicit realization of a variable flavor number scheme for final state
jets along the lines of the well known flavor number dependent evolution of the
strong coupling alpha_s and the parton distribution functions. | hep |
Renormalization of beta decay at three loops and beyond: The anomalous dimension for heavy-heavy-light effective theory operators
describing nuclear beta decay is computed through three-loop order in the
static limit. The result at order $Z^2\alpha^3$ corrects a previous result in
the literature. An all-orders symmetry is shown to relate the anomalous
dimensions at leading and subleading powers of $Z$ at a given order of
$\alpha$. The first unknown coefficient for the anomalous dimension now appears
at $O(Z^2\alpha^4)$. | hep |
Lattice Matter: I review recent developments in the study of strongly interacting field
theories with non-zero chemical potential mu. In particular I focus on (a) the
determination of the QCD critical endpoint in the (mu,T) plane; (b) superfluid
condensates in Two Color QCD; and (c) Fermi surface effects in the NJL model.
Some remarks are made concerning the relation of superconductivity with the
sign problem. | hep |
Lepton Flavor Violating Process in Degenerate and Inverse-Hierarchical
Neutrino Models: We have investigated the lepton flavor violation in the supersymmetric
framework assuming the large mixing angle MSW solution with the
quasi-degenerate and the inverse-hierarchical neutrino masses. In the case of
the quasi-degenerate neutrinos, the predicted branching ratio BR$(\mu \to e
\gamma)$ strongly depends on $m_\nu$ and $U_{e3}$. For $U_{e3}\simeq 0.05$ with
$m_\nu \simeq 0.3 \eV$, the prediction is close to the present experimental
upper bound if the right-handed Majorana neutrino masses are degenerate. On the
other hand, the prediction is larger than the experimental upper bound for
$U_{e3}\geq 0.05$ in the case of the inverse-hierarchical neutrino masses. | hep |
Constraining Dissipative Dark Matter Self-Interactions: We study the gravothermal evolution of dark matter halos in the presence of
dissipative dark matter self-interactions. Dissipative interactions are present
in many particle-physics realizations of the dark-sector paradigm and can
significantly accelerate the gravothermal collapse of halos compared to purely
elastic dark matter self-interactions. This is the case even when the
dissipative interaction timescale is longer than the free-fall time of the
halo. Using a semianalytical fluid model calibrated with isolated and
cosmological $N$-body simulations, we calculate the evolution of the halo
properties -- including its density profile and velocity dispersion profile --
as well as the core-collapse time as a function of the particle model
parameters that describe the interactions. A key property is that the inner
density profile at late times becomes cuspy again. Using 18 dwarf galaxies that
exhibit a corelike dark matter density profile, we derive constraints on the
strength of the dissipative interactions and the energy loss per collision. | hep |
Benchmarking regulator-sourced 2PI and average 1PI flow equations in
zero dimensions: We elucidate the regulator-sourced 2PI and average 1PI approaches for
deriving exact flow equations in the case of a zero dimensional quantum field
theory, wherein the scale dependence of the usual renormalisation group
evolution is replaced by a simple parametric dependence. We show that both
approaches are self-consistent, while highlighting key differences in their
behaviour and the structure of the would-be loop expansion. | hep |
Jet analysis by Deterministic Annealing: We perform a comparison of two jet clusterization algorithms. The first one
is the standard Durham algorithm and the second one is a global optimization
scheme, Deterministic Annealing, often used in clusterization problems, and
adapted to the problem of jet identification in particle production by high
energy collisions; in particular we study hadronic jets in WW production by
high energy electron positron scattering. Our results are as follows. First, we
find that the two procedures give basically the same output as far as the
particle clusterization is concerned. Second, we find that the increase of CPU
time with the particle multiplicity is much faster for the Durham jet
clustering algorithm in comparison with Deterministic Annealing. Since this
result follows from the higher computational complexity of the Durham scheme,
it should not depend on the particular process studied here and might be
significant for jet physics at LHC as well. | hep |
Gauge Theory and the Analytic Form of the Geometric Langlands Program: We present a gauge-theoretic interpretation of the "analytic" version of the
geometric Langlands program, in which Hitchin Hamiltonians and Hecke operators
are viewed as concrete operators acting on a Hilbert space of quantum states.
The gauge theory ingredients required to understand this construction -- such
as electric-magnetic duality between Wilson and 't Hooft line operators in
four-dimensional gauge theory -- are the same ones that enter in understanding
via gauge theory the more familiar formulation of geometric Langlands, but now
these ingredients are organized and applied in a novel fashion. | hep |
Fluid/Gravity Correspondence, Local Wald Entropy Current and
Gravitational Anomaly: We propose, in the framework of the fluid/gravity correspondence, a
definition for a local horizon entropy current for higher-curvature
gravitational theories. The current is well-defined to first order in fluid
gradients for general gravity actions with an algebraic dependence on the
Riemann tensor. As a detailed example, we consider five-dimensional
Einstein-Maxwell theory with a mixed gauge-gravitational Chern-Simons term. In
this theory, we construct the proposed entropy current on a charged black-brane
background, and show that it has a non-negative divergence. Moreover, a
complete correspondence between the charged black-brane horizon's dynamics and
the hydrodynamics of an anomalous four-dimensional field theory is established.
Our proposed entropy current is then found to coincide with the entropy current
of the anomalous field theory fluid. | hep |
Mono-Higgs Signature in the Scotogenic Model with Majorana Dark Matter: We study the phenomenology of scotogenic model in the case of Majorana Dark
Matter (DM) candidate. This scenario gives important consequences since the
parameter space of the model is almost unconstrained compared to the Inert
Higgs Doublet Model (or the scotogenic model with scalar DM), and hence, offers
new opportunities for discovery at future high energy collider, e.g. the
HL-LHC. As an example, we focus on the production of the Standard Model (SM)
Higgs boson in association with a pair of dark scalars. Owing to its clean
signature, the $\gamma\gamma$ decay channel of the SM Higgs boson is
investigated in great detail at both the HL-LHC (at $\sqrt{s}=14$ TeV) and the
future FCC-hh (at $\sqrt{s}=100$ TeV). After revisiting the LHC constraints
from run-II on the parameter space of the model, and selecting benchmark points
satisfying all the theoretical and experimental constraints, we found that
scalars with mass up to $140$ GeV ($160$ GeV) can be probed at the LHC (FCC-hh)
with a $3$ ab$^{-1}$ of integrated luminosity assuming $5\%$ of uncertainty. | hep |
Lectures on (abelian) Chern-Simons vortices: Various aspects including the construction and the symmetries of Abelian
Chern-Simons vortices are reviewed. Extended version of the Lectures delivered
at NIKHEF (Amsterdam), July 2006. Typos corrected, some refernces added. | hep |
Sensitivity measuring expected on the electromagnetic anomalous
couplings in the $t\bar tγ$ vertex at the FCC-he: In this paper, we consider the electroweak production cross-section of a
single anti-top-quark, a neutrino and a photon via charged current through the
$e^-p \to e^-\bar b \to \bar t \nu_e \gamma \to \bar t(\to W^- \to (qq', l^-
\bar\nu_l)+b) \nu_e\gamma$ signal. Further, we derived the sensitivity expected
to the magnetic dipole moment $(\hat a_V)$ and the electric dipole moment
$(\hat a_A)$ of the top-quark at the Future Circular Collider Hadron Electron
(FCC-he). We present our study for $\sqrt{s}=7.07, 10\hspace{0.8mm}TeV$, ${\cal
L}=50, 100, 300, 500, 1000\hspace{0.8mm}fb^{-1}$, $\delta_{sys}=0, 3,
5\hspace{0.8mm}\%$ and $P_{e^-}=0\%, 80\%, -80\%$, respectively. We find that
the sensitivity estimated on dipole moments of the top-quark is of the order of
magnitude ${\cal O}(10^{-1})$ for both hadronic and leptonic decay modes of
$W^-$: $\hat a_V=[-0.2308, 0.2204]$, $|\hat a_A|=0.2259$ at $95\%$ C.L. in the
hadronic channel with unpolarized electron beam $P_{e^-}=0\%$. Our results with
polarized electron beam for $P_{e^-}=80\%$ and $P_{e^-}=-80\%$ are $\hat
a_V=[-0.3428, 0.3321]$, $|\hat a_A|=0.3371$ and $\hat a_V=[-0.2041, 0.1858]$,
$|\hat a_A|=0.1939$ at $95\%$ C.L. in the hadronic channel. The corresponding
results for the leptonic channel with $P_{e^-}=0\%, 80\% -80\%$ are $\hat
a_V=[-0.3067, 0.2963]$, $|\hat a_A|=0.3019$, $\hat a_V=[-0.4563, 0.4456]$,
$|\hat a_A|=0.4505$ and $\hat a_V=[-0.2695, 0.2512]$, $|\hat a_A|=0.2592$,
respectively. The results for $\hat a_V$ and $\hat a_A$ in the leptonic channel
are weaker by a factor of 0.75 than those corresponding to the hadronic
channel. Given these prospective sensitivities we highlight that the FCC-he is
potential top-quark factory that is particularly well suited to sensitivity
study on its dipole moments and with cleaner environments. | hep |
Critical behaviors near the (tri-)critical end point of QCD within the
NJL model: We investigate the dynamical chiral symmetry breaking and its restoration at
finite density and temperature within the two-flavor Nambu-Jona-Lasinio model,
and mainly focus on the critical behaviors near the critical end point (CEP)
and tricritical point (TCP) of quantum chromodynamics. The multi-solution
region of the Nambu and Wigner ones is determined in the phase diagram for the
massive and massless current quark, respectively. We use the various
susceptibilities to locate the CEP/TCP and then extract the critical exponents
near them. Our calculations reveal that the various susceptibilities share the
same critical behaviors for the physical current quark mass, while they show
different features in the chiral limit. | hep |
Z' boson detection in the Minimal Quiver Standard Model: We undertake a phenomenological study of the extra neutral Z' boson in the
Minimal Quiver Standard Model and discuss limits on the model's parameters from
previous precision electroweak experiments, as well as detection prospects at
the Large Hadron Collider at CERN. We find that masses lower than around 700
GeV are excluded by the $Z$-pole data from the CERN-LEP collider, and below 620
GeV by experimental data from di-electron events at the Fermilab-Tevatron
collider. We also find that at a mass of 1 TeV the LHC cross section would show
a small peak in the di-lepton and top pair channel. | hep |
Generalized Poincare algebras and Lovelock-Cartan gravity theory: We show that the Lagrangian for Lovelock-Cartan gravity theory can be
re-formulated as an action which leads to General Relativity in a certain
limit. In odd dimensions the Lagrangian leads to a Chern-Simons theory
invariant under the generalized Poincar\'{e} algebra $\mathfrak{B}_{2n+1},$
while in even dimensions the Lagrangian leads to a Born-Infeld theory invariant
under a subalgebra of the $\mathfrak{B}_{2n+1}$ algebra. It is also shown that
torsion may occur explicitly in the Lagrangian leading to new torsional
Lagrangians, which are related to the Chern-Pontryagin character for the
$B_{2n+1}$ group. | hep |
Correlated Disorder in the SYK$_{2}$ model: We study the SYK$_{2}$ model of $N$ Majorana fermions with random quadratic
interactions through a detailed spectral analysis and by coupling the model to
2- and 4-point sources. In particular, we define the generalized spectral form
factor and level spacing distribution function by generalizing from the
partition function to the generating function. For $N=2$, we obtain an exact
solution of the generalized spectral form factor. It exhibits qualitatively
similar behavior to the higher $N$ case with a source term. The exact solution
helps understand the behavior of the generalized spectral form factor. We
calculate the generalized level spacing distribution function and the mean
value of the adjacent gap ratio defined by the generating function. For the
SYK$_2$ model with a 4-point source term, we find a Gaussian unitary ensemble
behavior in the near-integrable region of the theory, which indicates a
transition to chaos. This behavior is confirmed by the connected part of the
generalized spectral form factor with an unfolded spectrum. The departure from
this Gaussian random matrix behavior as the relative strength of the source
term is increased is consistent with the observation that the 4-point source
term alone, without the SYK$_2$ couplings turned on, exhibits an integrable
spectrum from the spectral form factor and level spacing distribution function
in the large $N$ limit. | hep |
Top-quark production measurements: Recent measurements of top-quark production at hadron colliders are reviewed.
The inclusive top-quark pair production is determined at four centre-of-mass
energies at Tevatron and LHC with experimental uncertainties that are close to
the uncertainties in theoretical calculations at next-to-next-to-leading order
in QCD. Several differential measurements are performed and compared to
simulation. Production of single top quarks is studied in the three different
production channels. Top-quark pair production with neutral and charged vector
bosons has been observed by the LHC experiments. Finally, production of
additional heavy flavour quark pairs ($b\bar{b}$, $t\bar{t}$) is studied or
searched for. | hep |
Newly observed D_{sJ}(3040) and the radial excitations of P-wave
charmed-strange mesons: Inspired by the newly observed $D_{sJ}(3040)^+$ state, in this work we
systemically study the two-body strong decays of P-wave charmed-strange mesons
with the first radial excitation. Under the assignment of $1^{+}(j^P=1/2^+)$,
i.e. the first radial excitation of $D_{s1}(2460)^+$, we find that the width of
$D_{sJ}(3040)^+$ is close to the lower limit of the BaBar measurement. This
indicates that it is reasonable to interpret $D_{sJ}(3040)^+$ as the first
radial excitation of $D_{s1}(2460)^+$. Our calculation further predicts that
$0^-+1^-$ channels e.g. $D^+K^{*0}$, $D^0 K^{*+}$ and $D_s^+\phi$ are important
for the search for $D_{sJ}(3040)^+$. To help future experiments finding the
remaining three P-wave charmed-strange mesons with the first radial excitation,
we present the predictions for the strong decays of these three P-wave
charmed-strange mesons. | hep |
QCD renormalization for the top-quark mass in a mass geometrical mean
hierarchy: $QCD$ renormalization for the top-quark mass is calculated in a mass
geometrical mean hierarchy, $m_d m_b = m_s^2$ and $m_u m_t = m_c^2$. The
physical mass, $m_t(m_t) = 160 {\pm} 50 GeV$ is obtained, which agrees very
well with electroweak precision measurement. | hep |
(beta beta)_{0 nu}-decay: a possible test of the nuclear matrix element
calculations: The existing calculations of the nuclear matrix elements of the neutrinoless
double beta-decay differ by about a factor three. This uncertainty prevents
quantative interpretation of the results of experiments searching for this
process. We suggest here that the observation of the neutrinoless double
beta-decay of several nuclei in future experiments of could allow to test
different calculations of the nuclear matrix elements through the direct
comparison of them with the experimental data. | hep |
Reply to A. Patrascioiu's and E. Seiler's comment on our paper "The
two-phase issue in the O(n) non-linear sigma-model: a Monte Carlo study": We reply to a comment by A. Patrascioiu and E. Seiler appeared in
hep-lat/9608138 on our paper hep-lat/9608002. | hep |
Effects of Shock Waves on Neutrino Oscillations in Three Supernova
Models: It has been realized that the shock wave effects play an important role in
neutrino oscillations during the supernova explosion. In recent years, with the
development of simulations about supernova explosion, we have a better
understanding about the density profiles and the shock waves in supernovae than
before. It has been shown that the appearance of shock waves not only varies
with time, but is also affected by the mass of the supernova. When the mass of
the supernova happens to be in a certain range (e.g. it equals 10.8 times the
mass of the sun), there might be a reverse shock wave, another sudden change of
density except the forward shock wave, emerging in the supernova. In addition,
there are some other time-dependent changes of density profiles in different
supernova models. Because of these complex density profiles, the expression of
the crossing probability at the high resonance, $P_H$, which we used previously
would be no longer applicable. In order to get more accurate and reasonable
results, we use the data of density profiles in three different supernova
models obtained from simulations to study the variations of $P_s$ (the survival
probability of $\nu_e\rightarrow\nu_e$), as well as $P_c$ (the conversion
probability of $\nu_x\rightarrow\nu_e$). It is found that the mass of the
supernova does make a difference on the behavior of $P_s$, and affects $P_c$ at
the same time. With the results of $P_s$ and $P_c$, we can estimate the number
of $\nu_e$ remained after they go through the matter in the supernova. | hep |
Composition of the Pseudoscalar Eta and Eta' Mesons: The composition of the eta and eta' mesons has long been a source of
discussion and is of current interest with new experimental results appearing.
We investigate what can be learnt from a number of different processes: V to P
gamma and P to V gamma (V and P are light vector and pseudoscalar mesons
respectively), P to gamma gamma, J/psi,psi' to P gamma, J/psi,psi' to P V, and
chi_{c0,2} to PP. These constrain the eta-eta' mixing angle to a consistent
value, phi approx 42 degrees; we find that the c cbar components are lesssim 5%
in amplitude. We also find that, while the data hint at a small gluonic
component in the eta', the conclusions depend sensitively on unknown form
factors associated with exclusive dynamics. In addition, we predict BR(psi' to
eta' gamma) approx 1 10^{-5} and BR(chi_{c0} to eta eta') approx 2 10^{-5} - 1
10^{-4}. We provide a method to test the mixing using chi_{c2} to eta eta, eta'
eta', and eta eta' modes and make some general observations on chi_{c0,2}
decays. We also survey the semileptonic and hadronic decays of bottom and
charmed mesons and find some modes where the mixing angle can be extracted
cleanly with the current experimental data, some where more data will allow
this, and some where a more detailed knowledge of the different amplitudes is
required. | hep |
The one example of Lorentz group: The aim of this work is to show, on the example of the behaviour of the
spinless charged particle in the homogeneous electric field, that one can
quantized the velocity of particle by the special gauge fixation. The work
gives also the some information about the theory of second quantisation in the
space of Hilbert- Fock and the theory of projectors in the Hilbert space. One
consider in Appendix the theory of the spinless charged particle in the
homogeneous addiabatical changed electrical field. | hep |
Taniguchi Lecture on Principal Bundles on Elliptic Fibrations: In this talk we discuss the description of the moduli space of principal
G-bundles on an elliptic fibration X-->S in terms of cameral covers and their
distinguished Prym varieties. We emphasize the close relationship between this
problem and the integrability of Hitchin's system and its generalizations. The
discussion roughly parallels that of [D2], but additional examples are included
and some important steps of the argument are illustrated. Some of the
applications to heterotic/F-theory duality were described in the accompanying
ICMP talk (hep-th/9802093). | hep |
Torsion Limits From $t\bar{t}$ Production at the LHC: Torsion models constitute a well known class of extended quantum gravity
models. In this work, one investigates the phenomenological consequences of a
torsion field interacting with top quarks at the LHC. A torsion field could
appear as a new heavy state characterized by its mass and couplings to
fermions. This new state would form a resonance decaying into a top anti-top
pair. The latest ATLAS $t\bar t$ production results from LHC 13 TeV data are
used to set limits on torsion parameters. The integrated luminosity needed to
observe torsion resonance at the next LHC upgrades are also evaluated,
considering different values for the torsion mass and its couplings to Standard
Model fermions. Finally, prospects for torsion exclusion at the future LHC
phases II and III are obtained using fast detector simulations. | hep |
Detecting an invisible Higgs boson at Fermilab Tevatron and CERN LHC: In this paper, we study the observability of an invisible Higgs boson at
Fermilab Tevatron and CERN LHC through the production channel $ q \bar{q} \to Z
H \to \ell^+\ell^-+ \ptmiss $, where $\ptmiss$ is reconstructed from the
$\ell^+\ell^-$ with $\ell=e$ or $\mu$. A new strategy is proposed to eliminate
the largest irreducible background, namely $ q \bar{q} \to Z(\to \ell^+\ell^-)
Z(\to \nu \bar\nu)$. This strategy utilizes the precise measurements of $ q
\bar{q} \to Z(\to \ell^+\ell^-) Z(\to \ell^+\ell^-)$. For $m_H=120$ GeV and
with luminosity $30 fb^{-1}$ at Tevatron, a $5\sigma$ observation of the
invisible Higgs boson is possible. For $m_H=114 \sim 140$ GeV with only $10
fb^{-1}$ luminosity at LHC, a discovery signal over $5\sigma$ can be achieved. | hep |
Electroweak Symmetry Breaking in the DSSM: We study the theoretical and phenomenological consequences of modifying the
Kahler potential of the MSSM two Higgs doublet sector. Such modifications
naturally arise when the Higgs sector mixes with a quasi-hidden conformal
sector, as in some F-theory GUT models. In the Delta-deformed Supersymmetric
Standard Model (DSSM), the Higgs fields are operators with non-trivial scaling
dimension 1 < Delta < 2. The Kahler metric is singular at the origin of field
space due to the presence of quasi-hidden sector states which get their mass
from the Higgs vevs. The presence of these extra states leads to the fact that
even as Delta approaches 1, the DSSM does not reduce to the MSSM. In
particular, the Higgs can naturally be heavier than the W- and Z-bosons.
Perturbative gauge coupling unification, a large top quark Yukawa, and
consistency with precision electroweak can all be maintained for Delta close to
unity. Moreover, such values of Delta can naturally be obtained in
string-motivated constructions. The quasi-hidden sector generically contains
states charged under SU(5)_GUT as well as gauge singlets, leading to a rich,
albeit model-dependent, collider phenomenology. | hep |
Measurement of $Br(D^{0}\to K^{-}π^{+})$ using Partila Reconstruction
of $\bar{B}\to D^{*+}X\ell^{-}\barν$: We present a measurement of the absolute branching fraction for $D^0 -> K^-
pi^+$ using the reconstruction of the decay chain $Bbar -> D^{*+} X l^- nubar
$, $D^{*+} -> D^0 pi^+$ where only the lepton and the low-momentum pion from
the $D^{*+}$ are detected. With data collected by the CLEO II detector at the
Cornell Electron Storage Ring, we have determined $Br(D^0 -> K^- pi^+)= [3.81
+- 0.15(stat.) +- 0.16(syst.)]%$. | hep |
Proton Structure Functions from Chiral Dynamics and QCD Constraints: The spin fractions and deep inelastic structure functions of the proton are
analyzed using chiral field theory involving Goldstone bosons. A detailed
comparison with recent chiral models sheds light on their successful
description of the spin fractions of the proton as being due to neglecting
helicity non-flip chiral transitions. This approximation is valid for zero mass
quarks but not for constituent quarks. Since the chiral spin fraction models
with the pure spin-flip approximation reproduce the measured spin fractions of
the proton, axialvector constituent-quark-Goldstone boson coupling is found to
be inconsistent with the proton spin data. Initial quark valence distributions
are then constructed using quark counting constraints at Bjorken $x \to 1$ and
Regge behavior at $x \to 0$. Sea quark distributions predicted by chiral field
theory on this basis have correct order of magnitude and shape. The spin
fractions agree with the data. | hep |
IR-improved Soft-wall AdS/QCD Model for Baryons: We construct an infrared-improved soft-wall AdS/QCD model for baryons by
considering the infrared-modified 5D conformal mass and Yukawa coupling of the
bulk baryon field. The model is also built by taking into account the
parity-doublet pattern for the excited baryons. When taking the bulk vacuum
structure of the meson field to be the one obtained consistently in the
infrared-improved soft-wall AdS/QCD model for mesons, we arrive at a consistent
prediction for the baryon mass spectrum in even and odd parity. The prediction
shows a remarkable agreement with the experimental data. We also perform a
calculation for the $\rho(a_1)$ meson-nucleon coupling constant and obtain a
consistent result in comparison with the experimental data and many other
models. | hep |
1-Loop Analysis of the Photon Self-Energy due to 3D-Gravity: A Maxwell-Chern-Simons field is minimally coupled to 3D-gravity. Feynman
rules are written down and 1-loop corrections to the gauge-field self-energy
are calculated. Transversality is verified and gauge-field dynamical mass
generation does not take place. | hep |
Indirect limits on the CPT violating background in the neutrino sector: CPT violation in the neutrino sector, suggested as a new way to reconcile
different neutrino anomalies, induces at the radiative level observable effects
among charged leptons, where high-precision tests of the CPT symmetry are
available. We show that, in the models with heavy right-handed Majorana
neutrinos, constraints imposed by these experiments require CPT violation in
neutrino spectrum be suppressed to a level undetectable for any conceivable
neutrino experiment. We find that the CPT violation in the neutrino sector may
evade indirect constraints only at the expense of light right-handed neutrinos
with small Yukawa couplings to the Standard Model sector or by allowing
non-locality well below the electroweak scale. | hep |
The semileptonic form factors of B and D mesons in the Quark Confinement
Model: The form factors of the weak currents, which appear in the semileptonic
decays of the heavy pseudoscalar mesons, are calculated within the quark
confinement model by taking into account, for the first time, the structure of
heavy meson vertex and the finite quark mass contribution in the heavy quark
propagators. The results are in quite good agreement with the experimental
data. | hep |
Supersymmetric Model of Radiative Seesaw Majorana Neutrino Masses: The radiative seesaw mechanism proposed recently is minimally extended to
include supersymmetry in a specific model. Relevant related issues such as
leptogenesis and dark matter are discussed. | hep |
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