Continuum limit of proton decay matrix elements in quenched lattice QCD

TL;DR

This paper computes proton decay matrix elements in quenched lattice QCD to improve theoretical predictions of proton lifetime in grand unified theories, using chiral Lagrangian methods and Wilson quark action.

Contribution

It provides the first continuum limit calculation of the parameters nd eta in quenched lattice QCD relevant for proton decay estimates.

Findings

nd eta values at 2 GeV are approximately 0.009 GeV^3.

Results include statistical and scale-setting uncertainties.

Continuum limit results are obtained for the parameters.

Abstract

We present a lattice QCD calculation of the parameters \alpha and \beta which are necessary in the theoretical estimation of the proton lifetime in grand unified theories (GUTs) using chiral lagrangian approach. The simulation is carried out using the Wilson quark action at three gauge coupling constants in the quenched approximation. We obtain |\alpha(2GeV)|=0.0091(08)(^{+10}_{-19})GeV^3 and |\beta(2GeV)|=0.0098(08)(^{+10}_{-20})GeV^3 in the continuum limit where the first error is statistical and the second one is due to scale setting.