Measurement of the inclusive b production cross section in pp collisions at √ s = 7 TeV

Abstract

This paper presents the measurement of inclusive b production cross section at the central mass energy of 7 TeV in CMS from the PAS BPH-10-007 and PAS BPH-10-009. The measurement are based on two different methods, one of which uses inclusive jets with secondary vertex tagging and the b-jet reconstruction efficiency and the other of which selects a sample of events containing jets and at least one muon whose the transverse momentum with respect to the closest jet axis discriminates b events from the background. At the every beginning of CMS run, 60 nb-1 data is used in the b-jet cross section study and jets in the region of 18GeV/c < pT < 300GeV/c and tracker acceptance |y| < 2.0 are constructed with the anti-kT algorithm within cone size R = 0.5 using Particle Flow objects. The systematic uncertainty is at 21% and the statistical one is 2%. For the jet with muon cross section is measured with 8.1 nb-1. Events are selected by requiring a good reconstructed muon and the systematic uncertainty is limited to be 20%. At last, both results will compare with the theoretic predictions of Pythia and QCD Monte Carlo predictions at next-to-leading order (NLO).