Study of B0 -> pi0pi0, B+ -> pi+pi0 and B+ -> K+pi0 decays

TL;DR

This paper reports updated measurements of branching fractions and asymmetries for specific B meson decays, providing insights into CP violation and isospin relations using data from the BaBar experiment.

Contribution

The study provides the most recent measurements of branching fractions and asymmetries for B0 -> pi0pi0, B+ -> pi+pi0, and B+ -> K+pi0 decays, including an upper bound on the angle difference |delta|.

Findings

BR(B0 -> pi0pi0) = (1.17 +/- 0.32 +/- 0.10)*10^{-6}

BR(B+ -> pi+pi0) = (5.8 +/- 0.6 +/- 0.4)*10^{-6}

BR(B+ -> K+pi0) = (12.0 +/- 0.7 +/- 0.6)*10^{-6}

Abstract

We present updated measurements of the branching fractions for the modes B0->pi0pi0, B+ -> pi+pi0, and B+ -> K+pi0. We also measure the time-integrated asymmetry C_pi0pi0 and the charge asymmetries A_CP(pi+pi0) and A_CP(K+pi0). Based on a sample of approximately 227 million BBar pairs collected by the BaBar detector at the PEP-II asymmetric-energy B Factory at SLAC, we measure BR(B0 -> pi0pi0) = (1.17 +/- 0.32 +/- 0.10)*10^{-6}, C_pi0pi0 = -0.12 +/- 0.56 +/- 0.06, where the first errors are statistical and the second are systematic. The B0 -> pi0pi0 signal has a significance of 4.9sigma including systematic uncertainties. We also measure BR(B+ -> pi+pi0) = (5.8 +/- 0.6 +/- 0.4)*10^{-6}, A_CP(pi+pi0) = -0.01 +/- 0.10 +/- 0.02, BR(B+ -> K+pi0) = (12.0 +/- 0.7 +/- 0.6)*10^{-6}, A_CP(K+pi0) = 0.06 +/- 0.06 +/- 0.01 . Using related BaBar measurements and isospin relations we find an upper bound on the angle difference |delta| = |alpha - alpha_eff| of 35 degrees at the 90% C.L.