LHCb CollaborationAdeva Andany, BernardoBorsato, MartinoChobanova, VeronikaCid Vidal, XabierDosil Suárez, ÁlvaroFernández Albor, Víctor ManuelGallas Torreira, Abraham AntonioGarcía Pardiñas, JuliánHernando Morata, José ÁngelLemos Cid, EdgarLucio Martínez, MiriamMartínez Santos, DiegoPlo Casasus, MáximoPrisciandaro, JessicaRamos Pernas, MiguelRomero Vidal, AntonioSaborido Silva, Juan JoséSanmartín Sedes, BraisSantamarina Ríos, CibránVázquez Regueiro, PabloVieites Díaz, MaríaVázquez Sierra, Carlos2020-05-192020-05-192016Aaij, R., Adeva, B., Adinolfi, M. et al. Measurement of the ratio of branching fractions B(B+c→J/ψK+)/B(B+c→J/ψπ+) . J. High Energ. Phys. 2016, 153 (2016). https://doi.org/10.1007/JHEP09(2016)1531029-8479http://hdl.handle.net/10347/22442The ratio of branching fractions RK/π≡B(B+c→J/ψK+)/B(B+c→J/ψπ+) is measured with pp collision data collected by the LHCb experiment at centre-of-mass energies of 7 TeV and 8 TeV, corresponding to an integrated luminosity of 3 fb−1. It is found to be R K/π = 0.079 ± 0.007 ± 0.003, where the first uncertainty is statistical and the second is systematic. This measurement is consistent with the previous LHCb result, while the uncertainties are significantly reduced.eng© CERN, for the bene t of the LHCb Collaboration. Article funded by SCOAP3. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0), which permits use, duplication, adaptation, distribution, and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.http://creativecommons.org/licenses/by/4.0/Branching fractionHadron-Hadron scattering (experiments)QCDjournal article10.1007/JHEP09(2016)153open access