Elsevier

Physics Letters B

Volume 705, Issues 1–2, 3 November 2011, Pages 9-27
Physics Letters B

Measurement of the ϒ(1S) production cross-section in pp collisions at s=7 TeV in ATLAS

https://doi.org/10.1016/j.physletb.2011.09.092Get rights and content
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open access

Abstract

A measurement of the cross-section for ϒ(1S)μ+μ production in proton–proton collisions at centre of mass energy of 7 TeV is presented. The cross-section is measured as a function of the ϒ(1S) transverse momentum in two bins of rapidity, |yϒ(1S)|<1.2 and 1.2<|yϒ(1S)|<2.4. The measurement requires that both muons have transverse momentum pTμ>4 GeV and pseudorapidity |ημ|<2.5 in order to reduce theoretical uncertainties on the acceptance, which depend on the poorly known polarisation. The results are based on an integrated luminosity of 1.13 pb−1, collected with the ATLAS detector at the Large Hadron Collider. The cross-section measurement is compared to theoretical predictions: it agrees to within a factor of two with a prediction based on the NRQCD model including colour-singlet and colour-octet matrix elements as implemented in Pythia while it disagrees by up to a factor of ten with the next-to-leading order prediction based on the colour-singlet model.

Cited by (0)

© CERN for the benefit of the ATLAS Collaboration.

E-mail address: [email protected].

a

Also at Laboratorio de Instrumentacao e Fisica Experimental de Particulas – LIP, Lisboa, Portugal.

b

Also at Faculdade de Ciencias and CFNUL, Universidade de Lisboa, Lisboa, Portugal.

c

Also at Particle Physics Department, Rutherford Appleton Laboratory, Didcot, United Kingdom.

d

Also at CPPM, Aix-Marseille Université and CNRS/IN2P3, Marseille, France.

e

Also at TRIUMF, Vancouver, BC, Canada.

f

Also at Department of Physics, California State University, Fresno, CA, United States.

g

Also at Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Krakow, Poland.

h

Also at Department of Physics, University of Coimbra, Coimbra, Portugal.

i

Also at Università di Napoli Parthenope, Napoli, Italy.

j

Also at Institute of Particle Physics (IPP), Canada.

k

Also at Department of Physics, Middle East Technical University, Ankara, Turkey.

l

Also at Louisiana Tech University, Ruston, LA, United States.

m

Also at Group of Particle Physics, University of Montreal, Montreal, QC, Canada.

n

Also at Institute of Physics, Azerbaijan Academy of Sciences, Baku, Azerbaijan.

o

Also at Institut für Experimentalphysik, Universität Hamburg, Hamburg, Germany.

p

Also at Manhattan College, New York, NY, United States.

q

Also at School of Physics and Engineering, Sun Yat-sen University, Guanzhou, China.

r

Also at Academia Sinica Grid Computing, Institute of Physics, Academia Sinica, Taipei, Taiwan.

s

Also at High Energy Physics Group, Shandong University, Shandong, China.

t

Also at California Institute of Technology, Pasadena, CA, United States.

u

Also at Section de Physique, Université de Genève, Geneva, Switzerland.

v

Also at Departamento de Fisica, Universidade de Minho, Braga, Portugal.

w

Also at Department of Physics and Astronomy, University of South Carolina, Columbia, SC, United States.

x

Also at KFKI Research Institute for Particle and Nuclear Physics, Budapest, Hungary.

y

Also at Institute of Physics, Jagiellonian University, Krakow, Poland.

z

Also at Department of Physics, Oxford University, Oxford, United Kingdom.

aa

Also at Institute of Physics, Academia Sinica, Taipei, Taiwan.

ab

Also at Department of Physics, The University of Michigan, Ann Arbor, MI, United States.

ac

Also at DSM/IRFU (Institut de Recherches sur les Lois Fondamentales de lʼUnivers), CEA Saclay (Commissariat a lʼEnergie Atomique), Gif-sur-Yvette, France.

ad

Also at Laboratoire de Physique Nucléaire et de Hautes Energies, UPMC and Université Paris-Diderot and CNRS/IN2P3, Paris, France.

ae

Also at Department of Physics, Nanjing University, Jiangsu, China.

Deceased.