### ?

## Precise measurement of the fs/fd ratio of fragmentation fractions and of Bs0 decay branching fractions

The ratio of the B0s and B0 fragmentation fractions, fs=fd, in proton-proton collisions at the LHC, is obtained as a function of B-meson transverse momentum and collision center-of-mass energy from the combined analysis of different B-decay channels measured by the LHCb experiment. The results are described by a linear function of the meson transverse momentum or with a function inspired by Tsallis statistics. Precise measurements of the branching fractions of the B0s → J=ψφ and B0s → D−s πþ decays are performed, reducing their uncertainty by about a factor of 2 with respect to previous world averages. Numerous B0s decay branching fractions, measured at the LHCb experiment, are also updated using the new values of fs=fd and branching fractions of normalization channels. These results reduce a major source of systematic uncertainty in several searches for new physics performed through measurements of B0s branching fractions.