Measurement of the fragmentation fraction ratio $f_s/f_d$ and its dependence on $B$ meson kinematics

The relative production rate of B0s and B0 mesons is determined with the hadronic decays B0s→D−sπ+ and B0→D−K+. The measurement uses data corresponding to 1.0 fb−1 of pp collisions at a centre-of-mass energy of s√=7 TeV recorded in the forward region with the LHCb experiment. The ratio of production rates, fs/fd, is measured to be 0.238±0.004±0.015±0.021, where the first uncertainty is statistical, the second systematic, and the third theoretical. This is combined with a previous LHCb measurement to obtain fs/fd=0.256±0.020. The dependence of fs/fd on the transverse momentum and pseudorapidity of the B meson is determined using the decays B0s→D−sπ+ and B0→D−π+. There is evidence for a decrease with increasing transverse momentum, whereas the ratio remains constant as a function of pseudorapidity. In addition, the ratio of branching fractions of the decays B0→D−K+ and B0→D−π+ is measured to be 0.0822±0.0011(stat)±0.0025(syst).
The relative production rate of and B (0) mesons is determined with the hadronic decays and B (0) → D (−) K (+). The measurement uses data corresponding to 1.0 fb(−1) of pp collisions at a centre-of-mass energy of TeV recorded in the forward region with the LHCb experiment. The ratio of production rates, f ( )s( ) /f ( )d( ), is measured to be 0.238 ± 0.004 ± 0.015 ± 0.021, where the first uncertainty is statistical, the second systematic, and the third theoretical. This is combined with a previous LHCb measurement to obtain f ( )s( ) /f ( )d( ) = 0.256 ± 0.020. The dependence of f ( )s( ) /f ( )d( ) on the transverse momentum and pseudorapidity of the B meson is determined using the decays and B (0) → D (−)π(+). There is evidence for a decrease with increasing transverse momentum, whereas the ratio remains constant as a function of pseudorapidity. In addition, the ratio of branching fractions of the decays B (0) → D (−) K (+) and B (0) → D (−)π(+) is measured to be 0.0822 ± 0.0011 (stat) ± 0.0025 (syst).