# XIIIth Quark Confinement and the Hadron Spectrum

31 July 2018 to 6 August 2018
Maynooth University
Europe/Dublin timezone

## Spontaneous Symmetry Breaking in the U(2) Planar Thirring Model?

2 Aug 2018, 15:30
30m
Hall D (Arts Bldg.)

### Hall D

#### Arts Bldg.

Talk G: Strongly Coupled Theories

### Speaker

Prof. Simon Hands (Swansea University)

### Description

Whether the U(2N) symmetry of Dirac fermions in 2+1 space-time dimensions is spontaneously broken by pair condensation once interactions are present is an important problem in non-perturbative quantum field theory. Here I focus on the Thirring model, whose interaction is a current-current contact term, using numerical simulations of a lattice model formulated with domain wall fermions - it has been demonstrated that U(2N) symmetry is recovered in the limit of infinite wall separation. I present results obtained with flavor numbers N=0, 1 and 2, and will attempt to put both upper and lower bounds on $N_c$, the critical number of flavors above which symmetry breaking does not occur even for arbitrarily strong coupling. The resulting $N_c$ will be shown to be very far from the value $N_c\approx6.6$ obtained with staggered lattice fermions, which not observe U(2N) symmetry.

### Primary author

Prof. Simon Hands (Swansea University)

### Presentation Materials

 maynooth_hands.pdf maynooth_hands.pdf