text:   Violation in Neutrino Oscillations",8,"[""New neutrino paper, this time with Rebekah Pestes a @VTPhysics grad student visiting BNL on the SCGSR program.\n\nWe discuss what deltaCP for neutrino oscillations really means and highlight the impact of how it's not actually a fundamental parameter. <LINK> 1/7"", 'If we do the rotations in the PMNS matrix in a different order, what changes? This figure shows that even if deltaPDG in the usual parameterization is constrained (that is, we ignore the T2K app data), delta in other parameterizations is constrained to within 150-210 degrees! 2/7 https://t.co/l4fHwPPiKl', '(The shaded regions show the effect of varying the osc params within their 3 σ regions.)\n\nWhile the premise might have been expected by some neutrino theorists, how tightly delta in other parameterizations is constrained was surprising to me anyway. 3/7', ""The reason is because |Ue3| is small (that is, theta13 is small). In other parameterizations this looks like sqrt(A+B*cos(delta)) so cos(delta) has to be near -1 for the cancellation to work. It's a bit subtle but we have useful approximations in the paper. 4/7"", ""The above figure also implies that precision in delta doesn't mean much of anything fundamental. We show that here where we plot what a precision on deltaPDG of 15deg looks like in different parameterizations; it could be as small as 1deg! 5/7 https://t.co/AXB0g1CXZX"", ""So what's the right answer? Within the context of oscillations it's always the Jarlskog (pictured here). This quantity is the closest to what is measured and doesn't require as much input from solar parameters to extract unlike using delta. 6/7 https://t.co/YzrZYQ1MFo"", ""While some aspect of these concepts has been discussed in the past, we focus on the situation in light of current measurements. As we zero in on the remaining parameters, keeping straight what is/isn't fundamental is more important than ever! 7/7"", '*this should say ""in the usual parameterization is UNconstrained""']",20,06,1878