Measurement of BB angular correlations based on secondary vertex reconstruction at ps = 7 TeV

Abstract

35 páginas, 8 figuras, 2 tablas.-- Open Access: This article is distributed under the terms of the Creative Commons Attribution Noncommercial License.-- CMS Collaboration: et al.A measurement of the angular correlations between beauty and anti-beauty hadrons (BB) produced in pp collisions at a centre-of-mass energy of 7 TeV at the CERN LHC is presented, probing for the rst time the region of small angular separation. The B hadrons are identi ed by the presence of displaced secondary vertices from their decays. The B hadron angular separation is reconstructed from the decay vertices and the primaryinteraction vertex. The di erential BB production cross section, measured from a data sample collected by CMS and corresponding to an integrated luminosity of 3:1 pb-1, shows that a sizable fraction of the BBpairs are produced with small opening angles. These studies provide a test of QCD and further insight into the dynamics of bb production.Acknowledge support from: FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia); Academy of Finland, ME, andHIP (Finland); CEAand CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTD (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA).Peer reviewe