This paper describes the first measurement of b-quark fragmentation fractions into bottom hadrons in Run II of the Tevatron Collider at Fermilab. The result is based on a 360pb-1 sample of data collected with the CDF II detector in pp̄ collisions at s=1.96TeV. Semileptonic decays of B̄0, B-, and B̄s0 mesons, as well as Λb0 baryons, are reconstructed. For an effective bottom hadron pT threshold of 7GeV/c, the fragmentation fractions are measured to be fu/fd=1.054±0.018(stat)-0.045+0.025(sys)±0. 058(B), fs/(fu+fd)=0.160±0.005(stat)-0.010+0.011(sys)-0.034+0.057(B), and fΛb/(fu+fd)=0.281±0.012(stat)-0.056+0.058(sys)-0.087+0.128(B), where the uncertainty B is due to uncertainties on measured branching ratios. The value of fs/(fu+fd) agrees within one standard deviation with previous CDF measurements and the world average of this quantity, which is dominated by LEP measurements. However, the ratio fΛb/(fu+fd) is approximately twice the value previously measured at LEP. The approximately 2σ discrepancy is examined in terms of kinematic differences between the two production environments. © 2008 The American Physical Society.
Publication Source (Journal or Book title)
Physical Review D - Particles, Fields, Gravitation and Cosmology
Aaltonen, T., Adelman, J., Akimoto, T., Albrow, M., González, B., Amerio, S., Amidei, D., Anastassov, A., Annovi, A., Antos, J., Aoki, M., Apollinari, G., Apresyan, A., Arisawa, T., Artikov, A., Ashmanskas, W., Attal, A., Aurisano, A., Azfar, F., Azzi-Bacchetta, P., Azzurri, P., Bacchetta, N., Badgett, W., Barbaro-Galtieri, A., Barnes, V., Barnett, B., Baroiant, S., & Bartsch, V. (2008). Measurement of ratios of fragmentation fractions for bottom hadrons in pp̄ collisions at s=1.96TeV. Physical Review D - Particles, Fields, Gravitation and Cosmology, 77 (7) https://doi.org/10.1103/PhysRevD.77.072003