Mass Spectrum and Bounds on the Couplings in Yukawa Models With Mirror-Fermions

TL;DR

This paper investigates the phase structure and fermion mass spectrum in an SU(2)_L x SU(2)_R symmetric Yukawa model with mirror-fermions, providing non-perturbative bounds on scalar couplings and comparing with perturbative results.

Contribution

It offers a non-perturbative analysis of the phase transition and bounds on scalar self-couplings in a mirror-fermion Yukawa model, extending understanding beyond perturbation theory.

Findings

Phase transition is consistent with second order.

Non-perturbative bounds on scalar self-couplings are established.

Numerical results agree with perturbative predictions near the transition.

Abstract

The $\rm SU(2)_L\otimes SU(2)_R$ symmetric Yukawa model with mirror-fermions in the limit where the mirror-fermion is decoupled is studied both analytically and numerically. The bare scalar self-coupling $\lambda$ is fixed at zero and infinity. The phase structure is explored and the relevant phase transition is found to be consistent with a second order one. The fermionic mass spectrum close to that transition is discussed and a first non-perturbative estimate of the influence of fermions on the upper and lower bounds on the renormalized scalar self-coupling is given. Numerical results are confronted with perturbative predictions.