Proton lifetime bounds from chirally symmetric lattice QCD RBC and UKQCD Collaborations

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.