Nuclear and Particle Theory Seminar

Date
Thu, May 26, 2016 3:00 pm - 4:30 pm
Location
PSC 3150

Description

**Time to be confirmed**

Speaker: Mikhail Shifman

Speaker Institution: University of Minnesota

Title: Can QCD Support Unknown Symmetry?

Abstract: I discuss "truncated" QCD suggested recently by Glozman et al. For two flavors it was observed that truncation restores the full chiral U(2)xU(2) symmetry of the Lagrangian. Moreover, additional enhancement of the above symmetry connecting representations with distinct Lorentz spins was observed. I argue that the chiral symmetry restoration in a confining theory could entail emergent (extra) dynamical flavors which would show up in the spectrum of color-singlet particles. As an example, I consider truncated QCD with a single massless Dirac quark. Assuming the validity of "truncated” QCD I demonstrate how a dynamical SU(2)_{fl} symmetry could emerge for massive spin-1 mesons in QCD with one quark flavor.