Search for the decay Bs -> D*-+ \pi+-

TL;DR

This paper reports a search for the rare decay Bs -> D*-+ pi+-, using LHCb data, setting an upper limit on its branching fraction to improve understanding of decay mechanisms.

Contribution

First search for the decay Bs -> D*-+ pi+- using LHCb data, establishing an upper limit on its branching fraction to inform decay process models.

Findings

No evidence for the decay was observed.

An upper limit on the branching fraction was set at 6.1 x 10^-6 (90% CL).

Systematic uncertainties were minimized using a normalization channel.

Abstract

A search for the decay Bs -> D*-+ \pi+- is presented using a data sample corresponding to an integrated luminosity of 1.0 fb-1 of pp collisions collected by LHCb. This decay is expected to be mediated by a W-exchange diagram, with little contribution from rescattering processes, and therefore a measurement of the branching fraction will help to understand the mechanism behind related decays such as Bs -> \pi+ \pi- and Bs -> D Dbar. Systematic uncertainties are minimised by using B0 -> D*-+ \pi+- as a normalisation channel. We find no evidence for a signal, and set an upper limit on the branching fraction of BR(Bs -> D*-+ \pi+-) < 6.1 (7.8) x10^(-6) at 90% (95%) confidence level.