Hadronic decay of a vector meson from the lattice

Abstract

We explore the decay of a vector meson to two pseudoscalar mesons on the lattice with $N_f=2$ flavours of sea quark. Although we are working with quark masses that do not allow a physical decay, we show how the transition rate can be evaluated from the amplitude for $\ddot{I}\to \ddot{I}€\ddot{I}€$ and from the annihilation component of $\ddot{I}€\ddot{I}€\to \ddot{I}€\ddot{I}€$. We explore the decay amplitude for two different pion momenta and find consistent results. The coupling strength we find is in agreement with experiment. We also find evidence for a shift in the $\ddot{I}$ mass caused by mixing with two pion states.

13 pages, version as accepted for Physics Letters B