Evidence For B0 -> rho0 K0S

TL;DR

This paper provides evidence for the decay B0->rho0 K0s, measuring its branching fraction and statistically excluding the zero-signal hypothesis with high confidence using data from the BABAR detector.

Contribution

First measurement of B0->rho0 K0s decay branching fraction with statistical significance, using a large data sample from BABAR at SLAC.

Findings

Branching fraction B0->rho0 K0s = (5.1 ± 1.0 ± 1.2) x 10^-6

Excludes zero signal at 6.1 sigma significance

Excludes zero B0->rho0 K0s at 3.5 sigma when including f0(600)K0s contribution

Abstract

We present evidence for the decay B0->rho0 K0s. The results are obtained from a data sample of 227 10^6 Y(4S) -> BBbar decays collected with the BABAR detector at the PEP-II asymmetric-energy B-Factory at SLAC. From a maximum-likelihood fit giving a yield of 99+/-19 events and efficiency estimated from simulation we make a preliminary measurement of the branching fraction B0->rho0 K0 =(5.1+/-1.0+/-1.2)10^-6 where the first error is statistical and the second systematic. The hypothesis of zero signal in the rho0 mass region, 600MeV-930MeV, is excluded at the 6.1sigma level. Allowing a B0->f_0(600)K0s contribution in the fit allows us to exclude the hypothesis of zero B0->rho0 K0s at the 3.5sigma level.