Measurement of the Branching Fraction for B^0 --> a1(1260)+-pi-+ with 535 Million BBbar Pairs

TL;DR

This paper reports a precise measurement of the branching fraction for the decay B^0 to a1(1260)+ pi- using a large dataset from the Belle detector, providing valuable data for understanding B meson decays.

Contribution

The study provides the first measurement of the B^0->a1(1260)+ pi- branching fraction with detailed statistical and systematic analysis, using 535 million BBbar pairs.

Findings

Branching fraction measured as (14.9 +- 1.6 +- 2.3) x 10^-6.

Large dataset enabled precise determination of decay probability.

Results contribute to understanding of B meson decay mechanisms.

Abstract

We present a measurement of the branching fraction for the decay B^0->a1+(1260)pi- with a1+->pi+pi+pi- using a data sample containing 535x10^6 BBbar pairs collected with the Belle detector at the KEKB asymmetric-energy e+e- collider operating at the Upsilon(4S) resonance. We measure the branching fraction Br(B^0->a1+pi-)Br(a1+->pi+pi+pi-) = (14.9 +- 1.6 +- 2.3)x10^-6, where the first and second errors are statistical and systematic, respectively.