Hadronic decays from the lattice

UKQCD Collaboration; Michael, C.; McNeile, C.

Hadronic decays from the lattice

Authors

UKQCD Collaboration

Michael, C.

McNeile, C.

Description

We discuss strategies to determine hadronic decay couplings from lattice studies. As an application, we explore the decay of a vector meson to two pseudoscalar mesons 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 $ρ\to ππ$ and from the annihilation component of $ππ\to ππ$. 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 $ρ$ mass caused by mixing with two pion states.
Proc. Latt03 (spectrum), 3 pages, 4 figs