Camboni, AlessandroComerma Montells, AlbertGarrido Beltrán, LluísGraciani Díaz, RicardoGraugés Pous, EugeniLópez Asamar, EliasPérez-Calero Yzquierdo, AntonioPicatoste Olloqui, EduardoPotterat, CédricRives Molina, Vicente JoséRuiz, Hugo (Ruiz Pérez)Vázquez Gómez, RicardAbellan Beteta, CarlosCalvo Gómez, MíriamOyanguren Campos, Arantza deRuiz Valls, PabloVilasis-Cardona, XavierLHCb Collaboration2019-04-082019-04-082013-04-011550-7998https://hdl.handle.net/2445/131831A search for the decay B 0 s → D * ∓ π ± is presented using a data sample corresponding to an integrated luminosity of 1.0     fb − 1 of p p 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 us to understand the mechanism behind related decays such as B 0 s → π + π − and B 0 s → D ¯¯¯ D . Systematic uncertainties are minimized by using B 0 → D * ∓ π ± as a normalization channel. We find no evidence for a signal, and set an upper limit on the branching fraction of B ( B 0 s → D * ∓ π ± ) < 6.1 ( 7.8 ) × 10 − 6 at 90% (95%) confidence level.8 p.application/pdfengcc by (c) CERN; LHCb Collaboration, 2013http://creativecommons.org/licenses/by/3.0/es/Física de partículesExperimentsParticle physicsExperimentsinfo:eu-repo/semantics/article6289732019-04-08info:eu-repo/semantics/openAccess