Measurement of quarkonium production at forward rapidity in pp collisions at sqrt{s}= 7 TeV

B. Abelev , Laurent Aphecetche (1) , Guillaume Batigne (1) , C. Cheshkov (2) , B. Cheynis (2) , H. Delagrange (1) , L. Ducroux (2) , B. Erazmus (1) , Magali Estienne (1) , Marie Germain (1) , J.-Y. Grossiord (2) , Maxime Guilbaud (2) , B. Hippolyte (3) , C. Kuhn (3) , A. Lardeux (1) , Gines Martinez Garcia (1) , A. Mas (1) , L. Massacrier (1) , A. Morreale (1) , Philippe Pillot (1) , L. Ronflette (1) , C. Roy (1) , X. Sanchez Castro (3) , Y. Schutz (1) , Alexandre Shabetai (1) , Diego Stocco (1) , R. Tieulent (2) , A. Uras (2) , R. Vernet (4) , M. Wang (1) , J. Zhu (1) , Y. Zoccarato (2) , N. Arbor (5) , G. Conesa Balbastre (5) , J. Faivre (5) , C. Furget (5) , R. Guernane (5) , S. Kox (5) , J.S. Real (5) , C. Silvestre (5) , Y.W. Baek (6) , V. Barret (6) , N. Bastid (6) , P. Crochet (6) , P. Dupieux (6) , S. Li (6) , X. Lopez (6) , F. Manso (6) , M. Marchisone (6) , S. Porteboeuf-Houssais (6) , P. Rosnet (6) , L. Valencia Palomo (6) , B. Vulpescu (6) , Z. Conesa Del Valle (7) , I. Das (7) , B. Espagnon (7) , C. Hadjidakis (7) , I. Lakomov (7) , C. Suire (7) , J. D. Tapia Takaki (7) , L. Valencia Palomo (7) , A. Baldisseri (8) , Herve Borel (8) , Javier Castillo Castellanos (8) , Jean-Luc Charvet (8) , Hugo Pereira da Costa (8) , A Rakotozafindrabe (9, 8)

1 SUBATECH - Laboratoire SUBATECH Nantes
2 IPNL - Institut de Physique Nucléaire de Lyon
3 IPHC - Institut Pluridisciplinaire Hubert Curien
4 CC-IN2P3 - Centre de Calcul de l'IN2P3
5 LPSC - Laboratoire de Physique Subatomique et de Cosmologie
6 LPC - Laboratoire de Physique Corpusculaire - Clermont-Ferrand
7 IPNO - Institut de Physique Nucléaire d'Orsay
8 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
9 DPHN - Département de Physique Nucléaire (ex SPhN)

The inclusive production cross sections at forward rapidity of J/psi, psi(2S), Upsilon(1S) and Upsilon(2S) are measured in pp collisions at sqrt{s} = 7 TeV with the ALICE detector at the LHC. The analysis is based in a data sample corresponding to an integrated luminosity of 1.35 pb^-1. Quarkonia are reconstructed in the dimuon-decay channel and the signal yields are evaluated by fitting the mu+mu- invariant mass distributions. The differential production cross sections are measured as a function of the transverse momentum pt and rapidity y, over the ranges 0 < pt < 20 GeV/c for J/psi, 0 < pt < 12 GeV/c for all other resonances and for 2.5 < y < 4. The measured cross sections integrated over pt and y, and assuming unpolarized quarkonia, are: sigma_{J/psi} = 6.69 +- 0.04 +- 0.63 microbarn, sigma_{psiprime} = 1.13 +- 0.07 +- 0.14 microbarn, sigma_{Upsilon(1S)} = 54.2 +- 5.0 +- 6.7 nb and sigma_{Upsilon(2S)} = 18.4 +- 3.7 +- 2.2 nb, where the first uncertainty is statistical and the second one is systematic. The results are compared to measurements performed by other LHC experiments and to theoretical models.

Domaines: Physique des Hautes Energies - Expérience [hep-ex]; Physique Nucléaire Expérimentale [nucl-ex]

B. Abelev, Laurent Aphecetche, Guillaume Batigne, C. Cheshkov, B. Cheynis, et al.. Measurement of quarkonium production at forward rapidity in pp collisions at sqrt{s}= 7 TeV. European Physical Journal C: Particles and Fields, 2014, 74, pp.2974. ⟨10.1140/epjc/s10052-014-2974-4⟩. ⟨in2p3-00959806⟩