Evidence for charged B meson decays to a1(1260)+/- pi0 and a1(1260)0 pi+/-

TL;DR

This paper reports measurements of branching fractions for charged B meson decays to specific a1(1260) pi final states, providing evidence with statistical significance from a large data sample.

Contribution

First measurement of these specific B meson decay modes, expanding understanding of charmed meson decay channels.

Findings

Branching fraction for B+/- --> a1(1260)+/- pi0 is (13.2 +/- 2.7 +/- 2.1) * 10^-6.

Branching fraction for B+/- --> a1(1260)0 pi+/- is (20.4 +/- 4.7 +/- 3.4) * 10^-6.

Evidence with 4.2 and 3.8 sigma significance for the respective decay modes.

Abstract

We present measurements of the branching fractions for the decays B+/- --> a1(1260)+/- pi0 and B+/- --> a1(1260)0 pi+/- from a data sample of 232 * 10^6 BB pairs produced in e+e- annihilation through the Y(4S) resonance. We measure the branching fraction B(B+/- --> a1(1260)+/- pi0) * B(a1(1260)+/- --> pi- pi+ pi+/-) = (13.2 +/- 2.7 +/- 2.1) * 10^-6 with a significance of 4.2 sigma, and the branching fraction B(B+/- --> a1(1260)0 pi+/-) * B(a1(1260)0 --> pi- pi+ pi0) = (20.4 +/- 4.7 +/- 3.4) * 10^-6 with a significance of 3.8 sigma, where the first error quoted is statistical and the second is systematic.