Time-Dependent CP Asymmetries in B0 -> Ks pi0 gamma transitions

TL;DR

This paper presents measurements of CP violation parameters in B0 -> Ks pi0 gamma decays using a large data sample, providing insights into time-dependent asymmetries and potential new physics effects.

Contribution

First measurement of CP violation parameters in B0 -> Ks pi0 gamma decays with detailed analysis near the K*0 resonance.

Findings

Measured S and A parameters with statistical and systematic uncertainties.

Observed CP asymmetry parameters consistent with Standard Model expectations.

Provided data for future studies of CP violation in radiative B decays.

Abstract

We report measurements of CP violation parameters in B0->Ks pi0 gamma transitions based on a data sample of 535x10^6 BB pairs collected with the Belle detector at the KEKB asymmetric-energy e+ e- collider. One neutral B meson is fully reconstructed in the B0->Ks pi0 gamma mode. The flavor of the accompanying B meson is identified from its decay products. For a Ks pi0 invariant mass up to 1.8 GeV/c^2, we obtain S = -0.10 +- 0.31 +- 0.07 and A = -0.20 +- 0.20 +- 0.06. For a Ks pi0 invariant mass near the K*0(892) resonance, we obtain S = -0.32 +0.36-0.33 +-0.05 and A=-0.20 +-0.24 +-0.05.