Delta I = 3/2, K to Pi Pi Decays with a Nearly Physical Pion Mass

Understand

The Delta I = 3/2 K to Pi Pi decay amplitude is calculated on RBC/UKQCD 32^3 x 64, L_s=32 dynamical lattices with 2+1 flavors of domain wall fermions using the DSDR and Iwasaki gauge action.

• The calculation is performed with a single pion mass (m_pi=141.9(2.3) MeV, partially quenched) and kaon mass (m_K=507.4(8.5) MeV) which are nearly physical, and with nearly energy conserving kinematics.
• Antiperiodic boundary conditions in two spatial directions are used to give the two pions non-zero ground state momentum.
• Results for time separations of 20, 24, 28 and 32 between the kaon and two-pion sources are computed and an error weighted average is performed to reduce the error.