Probability Distribution Function of the Diquark Condensate in Two Colours QCD

TL;DR

This paper investigates diquark condensation in two-color QCD at finite density, introducing a new calculation technique that provides evidence for a second order phase transition and aligns lattice results with effective theory predictions.

Contribution

It presents a novel method to compute diquark condensation directly at zero external source and extends theoretical understanding of symmetry breaking in two-color QCD.

Findings

Evidence for a second order phase transition with diquark condensate

Quantitative agreement between lattice results and effective Lagrangian calculations

A new technique for calculating diquark condensation at any number of flavors

Abstract

We consider diquark condensation in finite density lattice SU(2). We first present an extension of Vafa-Witten result, on spontaneous breaking of vector-like global symmetries, that allows us to formulate a no-go theorem for diquark condensation in a region of the chemical potential-mass parameter space. We then describe a new technique to calculate diquark condensation at any number of flavours directly at zero external source without using any potentially dangerous extrapolation procedure. We apply it to the strong coupling limit and find compelling evidences for a second order phase transition, where a diquark condensate appears, as well as quantitative agreement between lattice results and low-energy effective Lagrangian calculations.