Search for the decay B0 to a1 rho

TL;DR

This paper reports a search for the rare decay B0 to a1 rho using BaBar data, setting an upper limit on its branching fraction due to no significant signal observed.

Contribution

The study provides the first upper limit measurement on the branching fraction of B0 to a1 rho decay mode.

Findings

No significant signal observed for B0 to a1 rho decay.

An upper limit of 30 x 10^-6 on the branching fraction was established.

Assumption of a1+- decaying exclusively to rho0 pi+- was used in analysis.

Abstract

We present a search for the rare B-meson decay B0 to a1+- rho-+ with a_1+- to pi+ pi- pi+-. We use (110 +/- 1.2) x 10^6 Upsilon(4S) to BBbar decays collected with the BaBar detector at the PEP-II asymmetric-energy B Factory at SLAC. We obtain an upper limit of 30 x 10-6 (90% C.L.) for the branching fraction product B(B0 to a_1+- rho-+)B(a_1+- to pi+ pi- pi+-), where we assume that the a_1+- decays exclusively to rho0 pi+-.