Speaker
Ceran Hu
(Columbia University)
Description
In the lattice calculation of the two-photon contribution to the $K_{\rm L}\longrightarrow \mu^+\mu^-$ decay amplitude, the unphysical contribution from the $\eta$ intermediate state appears as a slowly decaying tail which is hard to remove due to the tiny mass difference between the $K_{\rm L}$ and $\eta$. We have developed methods to remove such an unphysical $\eta$ contribution from our lattice results. In this contribution, we present a preliminary GEVP study of the $\eta$ and $\eta^\prime$ masses, with which we determine the relevant matrix elements of $\eta$. Different methods to remove the unphysical $\eta$ contribution from the decay amplitude are examined, giving comparable results.
Primary authors
Ceran Hu
(Columbia University)
En-Hung Chao
