@article{7650e1664d144647b4b19eba346c696c,
title = "Observation of J/psi-pair production in pp collisions at root s=7 TeV",
abstract = "The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has been observed using an integrated luminosity of 37.5 pb(-1) collected with the LHCb detector. The production cross-section for pairs with both J/psi in the rapidity range 2 < y(J/psi) < 4.5 and transverse momentum p(T)(J/psi) < 10 GeV/c issigma(J/psi J/psi) = 5.1 +/- 1.0 +/- 1.1 nb,where the first uncertainty is statistical and the second systematic. (C) 2011 CERN. Published by Elsevier B.V. All rights reserved.",
keywords = "PSI-PSI-PRODUCTION, MESON PRODUCTION, UPSILON",
author = "R. Aaij and B. Adeva and M. Adinolfi and C. Adrover and A. Affolder and Z. Ajaltouni and J. Albrecht and F. Alessio and M. Alexander and G. Alkhazov and P.A. Cartelle and A.A. Alves and S. Amato and Y. Amhis and J. Anderson and R.B. Appleby and O.A. Gutierrez and F. Archilli and L. Arrabito and A. Artamonov and M. Artuso and E. Aslanides and G. Auriemma and S. Bachmann and J.J. Back and D.S. Bailey and V. Balagura and W. Baldini and R.J. Barlow and C. Barschel and S. Barsuk and W. Barter and A. Bates and C. Bauer and T. Bauer and A. Bay and I. Bediaga and K. Belous and I. Belyaev and E. Ben-Haim and M. Benayoun and G. Bencivenni and S. Benson and J. Benton and R. Bernet and M.O. Bettler and \{van Beuzekom\}, M. and A. Bien and S. Bifani and \{van den Brand\}, J. and \{LHCb collaboration\}",
year = "2012",
month = jan,
day = "16",
doi = "10.1016/j.physletb.2011.12.015",
language = "English",
volume = "707",
pages = "52--59",
journal = "Physics Letters B",
issn = "0370-2693",
publisher = "Elsevier B.V.",
number = "1",
}