出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：Measurements of the J=y and B+ c production cross-sections at p s = 7 TeV with the LHCb detector are presented. The analysis of J=y production is based on an integrated luminosity of 5.2 pb1 of data. The double differential cross-section of both prompt J=y and J=y from b is measured, as a function of the J=y transverse momentum pT and of the rapidity y in the fiducial region pT 2 [0;14] GeV/c and y 2 [2:0;4:5]. The integrated cross-section for prompt J=y production in this fiducial region is measured to be s (prompt J=y; pT < 14 GeV=c; 2:0 < y < 4:5) = 10:520:04(stat:) 1:40(syst:)+1:64 2:20(polarisation) b. The integrated cross-section for the production of J=y from b in the same fiducial region is measured to be s (J=y from b; pT < 14 GeV=c; 2:0 < y < 4:5) = 1:140:01(stat:)0:16(syst:)b. The B+ c production measurement is based on an integrated luminosity of 32 pb1. We present a preliminary measurement of the ratio of production cross-section times branching ratio for B+ c ! J=yp+ relative to that of B+!J=yK+, s(B+ c )BR(B+ c !J=yp+) s(B+)BR(B+!J=yK+) =(2:20:8(stat:)0:2(syst:))%.
