Measurement of Upsilon production in pp collisions at \sqrt{s} = 7 TeV

L. Eklund; S. Esen; A. Falabella; S. Farry; V. F. Albor; F. Rodrigues; S. Filippov; M. Fiore; M. Fiorini; C. Fitzpatrick; M. Fontana; F. Fontanelli; O. Francisco; E. Gersabeck; M. Gersabeck; P. Ghez; A. Gianelle; L. Giubega; C. Göbel; A. Golutvin; M. Gándara; E. Grauges; G. Graziani; P. Griffith; L. Grillo; O. Grünberg; E. Gushchin; C. Hadjivasiliou; G. Haefeli; C. Haen; T. Hafkenscheid; S. Hall; B. Hamilton; J. Harrison; T. Hartmann; K. Hennessy; P. Henrard; L. Henry; J. A. H. Morata; E. Herwijnen; M. Heß; A. Hicheur; P. H. Hopchev; P. H. Hopchev; W. Hulsbergen; P. Hunt; N. Hussain; D. Hutchcroft; D. Hynds; V. Iakovenko; P. Ilten; R. Jacobsson; A. Jaeger; E. Jans; P. Jaton; A. Jawahery; D. Johnson; C. Joram; B. Jost; N. Jurik; M. Kaballo; S. Kandybei; W. Kanso; B. Khanji; O. Kochebina; P. Koppenburg; A. Kozlinskiy; L. Kravchuk; K. Kreplin; M. Kreps; G. Krocker; P. Krokovny; F. Kruse; M. Kucharczyk; V. Kudryavtsev; K. Kurek; T. Kvaratskheliya; J. Lefrancois; O. Leroy; T. Lesiak; B. Leverington; E. Luppi; O. Lupton; F. Machefert; S. Malde; G. Manca; P. Marino; G. Martellotti; A. Martens; A. Sánchez; M. Martinelli; D. Santos; F. Vidal; D. M. Tostes; A. Massafferri; Z. Máthé; C. Matteuzzi; A. Mazurov; A. McNab; B. McSkelly; B. Meadows; F. Meier; J. M. Rodriguez; S. Monteil; M. Morandin; P. Morawski; R. Mureşan; B. Muryn; P. Naik; T. Nakada; N. Neri; S. Neubert; T. Nikodem; R. Oldeman; A. Oyanguren; A. Palano; A. Papanestis; G. Passaleva; A. Pearce; A. Pellegrino; P. Perret; B. Pietrzyk; T. Pilař; A. Poluektov; E. Polycarpo; A. Popov; J. Prisciandaro; A. Pritchard; C. Prouve; V. Pugatch; A. Puig; Navarro; G. Punzi; B. Rachwal; B. Rakotomiaramanana; S. Ricciardi; K. Rinnert; V. R. Molina; P. Robbe; V. Romanovsky; J. Rouvinet; P. Valls; B. Saitta; E. Santovetti; E. Smith

Paper

Measurement of Upsilon production in pp collisions at \sqrt{s} = 7 TeV

Abstract

The production of Upsilon(1S), Upsilon(2S) and Upsilon(3S) mesons in proton-proton collisions at the centre-of-mass energy of sqrt(s)=7 TeV is studied with the LHCb detector. The analysis is based on a data sample of 25 pb-1 collected at the Large Hadron Collider. The Upsilon mesons are reconstructed in the decay mode Upsilon -> mu+ mu- and the signal yields are extracted from a fit to the mu+ mu- invariant mass distributions. The differential production cross-sections times dimuon branching fractions are measured as a function of the Upsilon transverse momentum pT and rapidity y, over the range pT < 15 GeV/c and 2.0 < y < 4.5. The cross-sections times branching fractions, integrated over these kinematic ranges, are measured to be sigma(pp -> Upsilon(1S) X) x B(Upsilon(1S)->mu+ mu-) = 2.29 {\pm} 0.01 {\pm} 0.10 -0.37 +0.19 nb, sigma(pp -> Upsilon(2S) X) x B(Upsilon(2S)->mu+ mu-) = 0.562 {\pm} 0.007 {\pm} 0.023 -0.092 +0.048 nb, sigma(pp -> Upsilon(3S) X) x B(Upsilon(3S)->mu+ mu-) = 0.283 {\pm} 0.005 {\pm} 0.012 -0.048 +0.025 nb, where the first uncertainty is statistical, the second systematic and the third is due to the unknown polarisation of the three Upsilon states.