Physical matrix elements for Delta I = 3/2 channel K to pi pi decays

TL;DR

This paper computes K to pi pi decay matrix elements for the Delta I=3/2 channel using lattice QCD with domain wall fermions, providing insights into weak decay processes.

Contribution

It presents the first calculation of these matrix elements on 32^3 x 64 lattices with 2+1 dynamical flavors, including interpolation to physical kinematics.

Findings

Preliminary value for |A_2| parameter

Matrix elements interpolated to physical energies

Demonstrates feasibility of lattice QCD for decay amplitudes

Abstract

K to pi pi matrix elements of the electroweak operator Q_(27,1)^Delta I=3/2 are calculated on the RBC/UKQCD 32^3 x 64, L_s=16 lattices, using 2+1 dynamical flavors and domain wall fermions, with an inverse lattice spacing of a^(-1)=2.42(4) GeV. Data is interpolated or extrapolated to energy conserving kinematics and a preliminary calculation of the experimental parameter |A_2| is performed.