ATLAS collaboration (2853 authors)Aguilar-Saavedra, Juan AntonioAmor Dos Santos, Susana PatriciaAnjos, NunoAraque, Juan PedroCantrill, RobertCarvalho, JoãoCastro, Nuno FilipeConde Muiño, PatriciaDa Cunha Sargedas De Sousa, Mario JoseFiolhais, MiguelGalhardo, BrunoGomes, AgostinhoGonçalo, RicardoJorge, PedroLopes, LourencoMachado Miguens, JoanaMaio, AméliaManeira, JoséOnofre, AntónioPalma, AlbertoPedro, RutePina, João AntonioSantos, HelenaSaraiva, JoãoSilva, JoséTavares Delgado, AdemarVeloso, FilipeWolters, Helmut2019-02-042019-02-042015-12-30http://dx.doi.org/10.1103/PhysRevLett.115.262001http://hdl.handle.net/10400.26/26897With an integrated luminosity of 2.47  fb-1 recorded by the ATLAS experiment at the LHC, the exclusive decays Bs0→J/ψϕ and Bd0→J/ψK*0 of B mesons produced in pp collisions at s=7  TeV are used to determine the ratio of fragmentation fractions fs/fd. From the observed Bs0→J/ψϕ and Bd0→J/ψK*0 yields, the quantity (fs/fd)[B(Bs0→J/ψϕ)/B(Bd0→J/ψK*0)] is measured to be 0.199±0.004(stat)±0.008(syst). Using a recent theory prediction for [B(Bs0→J/ψϕ)/B(Bd0→J/ψK*0)] yields (fs/fd)=0.240±0.004(stat)±0.010(syst)±0.017(th). This result is based on a new approach that provides a significant improvement of the world average.engjournal article2019-02-04