Measurement of Branching Fraction and Direct CP Asymmetry in B0-->rho0 pi0 Decays

TL;DR

This paper reports the first measurement of the branching fraction and direct CP asymmetry in B0 --> rho0 pi0 decays using data from the Belle detector, providing insights into CP violation in B meson decays.

Contribution

It presents the first measurement of direct CP violation and the branching fraction for B0 --> rho0 pi0 decays, using a large data sample from Belle.

Findings

Branching fraction measured as (3.12^{+0.88}_{-0.82} (stat) +/- 0.33 (syst) ^{+0.50}_{-0.68} (model)) x 10^{-6}

Signal significance of 4.2 standard deviations including systematic uncertainties

First measurement of direct CP asymmetry in this decay mode

Abstract

We report a measurement of the decay B0 --> rho0 pi0, using 386 x 10^6 BB-bar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We detect 51^{+14}_{-13} signal events with a significance of 4.2 standard deviations, including systematic uncertainties, and measure the branching fraction to be B(B0 --> rho0 pi0) = (3.12^{+0.88}_{-0.82} (stat) +/- 0.33 (syst) ^{+0.50}_{-0.68} (model)) x 10^{-6}. We also perform the first measurement of direct CP violating asymmetry in this mode.