Proton lifetime bounds from chirally symmetric lattice QCD

Abstract

We present results for the matrix elements relevant for proton decay in Grand Unified Theories (GUTs). The calculation is performed at a fixed lattice spacing a −1 = 1.73(3) GeV using 2+1 flavors of domain wall fermions on lattices of size 16 3 × 32 and 24 3 × 64 with a fifth dimension of length 16. We use the indirect method which relies on an effective field theory description of proton decay, and we estimate the low energy constants, α = −0.0112(25) GeV 3 and β = 0.0120(26) GeV 3 . We relate these low energy constants to the proton decay matrix elements using leading order chiral perturbation theory.