Measurement of the production cross sections for a Z boson and one or more b jets in pp collisions at √s = 7 TeV

Authors

S. Chatrchyan, Yerevan Physics Institute
Ekaterina Avdeeva, University of Nebraska-LincolnFollow
Kenneth A. Bloom, University of Nebraska-LincolnFollow
S. Bose, University of Nebraska-LincolnFollow
Daniel R. Claes, University of Nebraska-LincolnFollow
Aaron Dominguez, University of Nebraska-LincolnFollow
M. Eads, University of Nebraska-LincolnFollow
Rebeca Gonzalez Suarez, University of Nebraska-LincolnFollow
J. Keller, University of Nebraska-Lincoln
Ilya Kravchenko, University of Nebraska-LincolnFollow
J. Lazo-Flores, University of Nebraska-LincolnFollow
S. Malik, University of Nebraska-LincolnFollow
F. Meier, University of Nebraska-LincolnFollow
Gregory R. Snow, University of Nebraska-LincolnFollow
The CMS collaboration

Date of this Version

6-19-2014

Citation

JHEP06(2014)120; doi:10.1007/JHEP06(2014)120

Comments

Copyright © 2014 CERN, issued under CC license, published by Springer.

Abstract

The production of a Z boson, decaying into two leptons and produced in association with one or more b jets, is studied using proton-proton collisions delivered by the LHC at a centre-of-mass energy of 7TeV. The data were recorded in 2011 with the CMS detector and correspond to an integrated luminosity of 5 fb⁻¹. The Z(ℓℓ)+b-jets cross sections (where ℓℓ = μμ or ee) are measured separately for a Z boson produced with exactly one b jet and with at least two b jets. In addition, a cross section ratio is extracted for a Z boson produced with at least one b jet, relative to a Z boson produced with at least one jet.The measured cross sections are compared to various theoretical predictions, and the data favor the predictions in the five-flavor scheme, where b quarks are assumed massless. The kinematic properties of the reconstructed particles are compared with the predictions from the MadGraph event generator using the pythia parton shower simulation.