Measurement of the B0 -> Lambda-bar p pi Branching Fraction and Study of the Decay Dynamics

TL;DR

This paper reports a precise measurement of the B0 -> Lambda-bar p pi decay branching fraction using BaBar data, revealing a near-threshold enhancement in the di-baryon invariant mass spectrum.

Contribution

First measurement of the B0 -> Lambda-bar p pi branching fraction with detailed decay dynamics analysis using a large data sample.

Findings

Branching fraction measured as (3.30 +- 0.53 (stat) +- 0.31 (syst)) x 10^-6

Observation of near-threshold enhancement in the di-baryon mass spectrum

Analysis of decay dynamics consistent with previous baryonic B decay patterns

Abstract

We present a measurement of the B0 -> Lambda-bar p pi branching fraction performed using the BaBar detector at the PEP-II asymmetric energy e+e- collider. Based on a 232 million BB-bar pairs data sample we measure: BR(B0 -> Lambda-bar p pi) = [ 3.30 +- 0.53 (stat.) +- 0.31(syst.) ] x 10^-6. A measurement of the differential spectrum as a function of the di-baryon invariant mass m(Lambda p) is also presented; this shows a near-threshold enhancement similar to that observed in other baryonic B decays.