Measurement of the Dependence of the Hadron Production Fraction Ratios ${f}_{s}/{f}_{u}$ and ${f}_{d}/{f}_{u}$ on $B$ Meson Kinematic Variables in Proton-Proton Collisions at $\sqrt{s}=13\text{}\text{}\mathrm{TeV}$

The dependence of the ratio between the ${B}_{s}^{0}$ and ${B}^{+}$ hadron production fractions, ${f}_{s}/{f}_{u}$, on the transverse momentum (${p}_{T}$) and rapidity of the $B$ mesons is studied using the decay channels ${B}_{s}^{0}\to J/\psi \varphi $ and ${B}^{+}\to J/\psi {K}^{+}$. The analysis uses a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment in 2018 and corresponding to an integrated luminosity of $61.6\text{}\text{}{\mathrm{fb}}^{-1}$. The ${f}_{s}/{f}_{u}$ ratio is observed to depend on the $B$ ${p}_{T}$ and to be consistent with becoming asymptotically constant at large ${p}_{T}$. No rapidity dependence is observed. The ratio of the ${B}^{0}$ to ${B}^{+}$ meson production fractions, ${f}_{d}/{f}_{u}$, is also measured, for the first time in proton-proton collisions, using the ${B}^{0}\to J/\psi {K}^{*0}$ decay channel. The result is found to be within 1 standard deviation of unity and independent of ${p}_{T}$ and rapidity, as expected from isospin invariance.