Measurements of Branching Fractions and Polarization in B > K^* rho Decays

TL;DR

This study measures the branching fractions and polarization in specific B meson decays, providing new experimental limits and polarization data that enhance understanding of charmless vector-vector decay processes.

Contribution

It reports the first measurements of branching fractions and polarization in B -> K^* rho decays using Belle data, including upper limits and polarization fractions.

Findings

Branching fraction B(B^+ -> K^{*0} rho^+) = (6.6 +- 2.2(stat.) +- 0.8(syst.)) x 10^{-6}

Upper limits set for B^0 decays: <2.6 x 10^{-6} and <5.2 x 10^{-6}

Longitudinal polarization fraction R_0 = 0.50 +- 0.19 (stat.) +0.05-0.07 (syst.)

Abstract

We present results of a study of the charmless vector-vector decays B^0 -> K^{*0} rho^0 and B^+ ->K^{*0} rho^+. The results are based on a 140 fb^{-1} data sample collected by the Belle detector at the KEKB asymmetric e^+e^- collider. We obtain the branching fraction B(B^+ -> K^{*0} rho^+)=(6.6 +- 2.2(stat.) +- 0.8 (syst.)) x 10^{-6}, and set upper limits on the branching fractions B(B^0 -> K^{*0} rho^0)<2.6 x 10^{-6} and B(B^0 -> f_0(980) K^{*0})<5.2 x 10^{-6}. We also perform a helicity analysis of the rho and K^* vector mesons in the decay B^+ -> K^{*0} rho^+, and obtain the longitudinal polarization fraction R_0(B^+ -> K^{*0} rho^+)=0.50 +- 0.19(stat.)+0.05-0.07}(syst.).