Journal article
Determination of the Ratio of b -Quark Fragmentation Fractions fs /fd in pp Collisions at s =7 TeV with the ATLAS Detector
G Aad, B Abbott, J Abdallah, O Abdinov, R Aben, M Abolins, OS Abouzeid, H Abramowicz, H Abreu, R Abreu, Y Abulaiti, BS Acharya, L Adamczyk, DL Adams, J Adelman, S Adomeit, T Adye, AA Affolder, T Agatonovic-Jovin, J Agricola Show all
Physical Review Letters | Published : 2015
Open access
Abstract
With an integrated luminosity of 2.47 fb-1 recorded by the ATLAS experiment at the LHC, the exclusive decays Bs0→J/ψφ and Bd0→J/ψK∗0 of B mesons produced in pp collisions at s=7 TeV are used to determine the ratio of fragmentation fractions fs/fd. From the observed Bs0→J/ψφ and Bd0→J/ψK∗0 yields, the quantity (fs/fd)[B(Bs0→J/ψφ)/B(Bd0→J/ψK∗0)] is measured to be 0.199±0.004(stat)±0.008(syst). Using a recent theory prediction for [B(Bs0→J/ψφ)/B(Bd0→J/ψK∗0)] yields (fs/fd)=0.240±0.004(stat)±0.010(syst)±0.017(th). This result is based on a new approach that provides a significant improvement of the world average.
Grants
Awarded by European Commission
Funding Acknowledgements
We thank CERN for the very successful operation of the LHC, as well as the support staff from our institutions without whom ATLAS could not be operated efficiently. We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWFW and FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC, and CFI, Canada; CERN; CONICYT, Chile; CAS, MOST, and NSFC, China; COLCIENCIAS, Colombia; MSMT CR, MPO CR, and VSC CR, Czech Republic; DNRF, DNSRC, and Lundbeck Foundation, Denmark; EPLANET, ERC, and NSRF, European Union; IN2P3-CNRS, CEA-DSM/IRFU, France; GNSF, Georgia; BMBF, DFG, HGF, MPG, and AvH Foundation, Germany; GSRT and NSRF, Greece; ISF, MINERVA, GIF, I-CORE, and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; FOM and NWO, Netherlands; BRF and RCN, Norway; MNiSW and NCN, Poland; GRICES and FCT, Portugal; MNE/IFA, Romania; MES of Russia and ROSATOM, Russian Federation; JINR; MSTD, Serbia; MSSR, Slovakia; ARRS and MIZS, Slovenia; DST/NRF, South Africa; MINECO, Spain; SRC and Wallenberg Foundation, Sweden; SER, SNSF, and Cantons of Bern and Geneva, Switzerland; NSC, Taiwan; TAEK, Turkey; STFC, the Royal Society and Leverhulme Trust, United Kingdom; DOE and NSF, USA. The crucial computing support from all WLCG partners is acknowledged gratefully, in particular, from CERN and the ATLAS Tier-1 facilities at TRIUMF (Canada), NDGF (Denmark, Norway, Sweden), CC-IN2P3 (France), KIT/GridKA (Germany), INFN-CNAF (Italy), NL-T1 (Netherlands), PIC (Spain), ASGC (Taiwan), RAL (UK) and BNL (USA), and in the Tier-2 facilities worldwide.