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

• Main Authors: CMS Collaboration (Author), Apyan, Aram (Contributor), Bauer, Gerry P (Contributor), Busza, Wit (Contributor), Cali, Ivan Amos (Contributor), Chan, Matthew Hans (Contributor), Di Matteo, Leonardo (Contributor), Dutta, Valentina (Contributor), Gomez-Ceballos, Guillelmo (Contributor), Goncharov, Maxim (Contributor), Gulhan, Doga Can (Contributor), Kim, Yongsun (Contributor), Klute, Markus (Contributor), Lai, Yue Shi (Contributor), Levin, Andrew Michael (Contributor), Luckey Jr, P David (Contributor), Ma, Teng (Contributor), Nahn, Steven (Contributor), Paus, Christoph M. E. (Contributor), Ralph, Duncan Kelley (Contributor), Roland, Christof E (Contributor), Roland, Gunther M (Contributor), Stephans, George S. F. (Contributor), Stoeckli, Fabian (Contributor), Sumorok, Konstanty C (Contributor), Velicanu, Dragos Alexandru (Contributor), Wolf, Roger (Contributor), Wyslouch, Boleslaw (Contributor), Yang, Ming (Contributor), Yilmaz, Yetkin (Contributor), Yoon, A. S. (Contributor), Zanetti, Marco (Contributor), Wyslouch, Victoria (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor), Massachusetts Institute of Technology. Laboratory for Nuclear Science (Contributor)
• Format: Article
• Language: English
• Published: Springer Berlin Heidelberg, 2018-06-07T13:07:45Z.
• Subjects: Article
• Online Access: Get fulltext

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 7 TeV. The data were recorded in 2011 with the CMS detector and correspond to an integrated luminosity of 5 fb[superscript -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 favour the predictions in the five-flavour 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. [Figure not available: see fulltext.] Keywords: Jet physics; Hadron-Hadron Scattering