Analysis of the Charmed Semileptonic Decay D^+ -> rho^0 mu^+ nu

Abstract

Using data collected by the FOCUS experiment at Fermilab, we present a new measurement of the charm semileptonic branching ratio BR(D^+ -> rho^0 mu^+ nu)/BR(D^+ -> K*0Bar mu^+ nu). From a sample of 320 +- 44 and 11372 +- 161 D^+ -> rho^0 mu^+ nu and D^+ -> K*0Bar mu^+ nu events respectively, we find BR(D^+ -> rho^0 mu^+ nu)/BR(D^+ -> K*0Bar mu^+ nu) = 0.041 +- 0.006 (stat) +- 0.004(syst).