Fluctuation Induced First Order Phase Transitions

TL;DR

This paper investigates how quantum fluctuations induce first order phase transitions in a $U(N) imes U(N)$ scalar model, providing evidence in four dimensions and implications for QCD in three dimensions.

Contribution

It demonstrates quantum fluctuation-induced first order transitions in a $U(N) imes U(N)$ model and discusses their relevance to QCD phase transitions.

Findings

Quantum fluctuations induce first order transitions in four dimensions.

Even with $U_A(1)$ symmetry restoration, QCD may have a weak first order transition.

Simulation results support the theoretical analysis.

Abstract

We study a $U(N)\times U(N)$ symmetric scalar field model in four and three dimensions. First, using our data in four dimensions in the weak coupling region, we demonstrate explicitly that the observed first order phase transition is induced by quantum fluctuations. Next, based on the renormalization group and our new simulation results in three dimensions we argue that even if the $U_A(1)$ symmetry is restored below the critical temperature the QCD finite temperature chiral phase transition for two flavor could be extremely weak first order. Contribution to Lattice '93 proceedings. Needs espcrc2.sty file (included). Search Figure1.ps, Figure2.ps, ... for postscript files.