Measurements of Branching Fraction and Polarization in B^+ -> rho^+ K^{*0} Decay

TL;DR

This study measures the branching fraction and polarization in the decay B^+ to rho^+ K^{*0} using Belle detector data, providing insights into charmless vector-vector B meson decays.

Contribution

First measurement of branching fraction and polarization fraction for B^+ to rho^+ K^{*0} decay based on Belle data.

Findings

Branching fraction: (8.9 ± 1.7 (stat) ± 1.2 (syst)) × 10^{-6}

Longitudinal polarization fraction: 0.43 ± 0.11 (stat)^{+0.05}_{-0.02} (syst)

Abstract

We present the results of a study of the charmless vector-vector decay $B^+\to \rho^+K^{*0}$, based on 253 fb$^{-1}$ of data collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. We obtain the branching fraction ${\cal B}(B^+\to\rho^+ K^{*0})=(8.9\pm 1.7(\rm stat)\pm 1.2 (\rm syst))\times 10^{-6}$. We also perform a helicity analysis of the $\rho$ and $K^*$ vector mesons, and obtain the longitudinal polarization fraction $f_L(B^+\to \rho^+ K^{*0})=0.43 \pm 0.11(\rm stat)^{+0.05}_{-0.02}(\rm syst)$.