# Poster presented by Steven Gottlieb

Poster Session

Topic: Heavy Quarks

### Heavy-light Decay Constants with Dynamical Gauge Configurations and Wilson or Improved Valence Quark Actions

Abstract: Decay constants for the $B$ and $B_s$ mesons are crucial for the accurate determination of the CKM mixing matrix. In prior years, we have completed our calculations within the quenched approximation. We now have results at three $\beta$ values for dynamical gauge configurations using two flavors of Kogut-Susskind quarks with a range of masses. These are analyzed with a Wilson valence quark action, and an extrapolation to the continuum is attempted. In addition, we present preliminary results based on a fat-link'' clover valence quark action.

Massimo Campostrini,   campo@mailbox.difi.unipi.it