Badalov, A.Casanova Mohr, R.Garrido Beltrán, LluísGascón Fora, DavidGraciani Diaz, RicardoGraugés Pous, EugeniMarin Benito, CarlaPicatoste Olloqui, EduardoRives Molina, Vicente JoséRuiz, Hugo (Ruiz Pérez)LHCb collaboration2022-05-192022-05-192015-06-181126-6708https://hdl.handle.net/2445/185809The first observation of the B0 s → D∗∓ s K± decay is reported using 3.0 fb−1 of protonproton collision data collected by the LHCb experiment. The D∗∓ s mesons are reconstructed through the decay chain D∗∓ s → γD∓ s (K∓K±π ∓). The branching fraction relative to that for B0 s → D∗− s π + decays is measured to be B(B0 s→ D∗∓ s K±)/B(B0 s→ D∗− s π +) = 0.068 ± 0.005+0.003 −0.002, where the first uncertainty is statistical and the second is systematic. Using a recent measurement of B(B0 s → D∗− s π +), the absolute branching fraction of B0 s → D∗∓ s K± is measured as B(B0 s → D∗∓ s K±) = ( 16.3 ± 1.2 (stat) +0.7 −0.5 (syst) ± 4.8 (norm) ) × 10−5 , where the third uncertainty is due to the uncertainty on the branching fraction of the normalisation channel.18 p.application/pdfengcc-by (c) Badalov, A. et al., 2015https://creativecommons.org/licenses/by/4.0/HadronsGran Col·lisionador d'HadronsFísica de partículesExperimentsHadronsLarge Hadron Collider (France and Switzerland)Particle physicsExperimentsinfo:eu-repo/semantics/article6567762022-05-19info:eu-repo/semantics/openAccess