The production of J/psi mesons is studied with the LHCb detector using data from pp collisions at root s = 2.76 TeV corresponding to an integrated luminosity of 71 nb(-1). The differential cross-section for inclusive J/psi production is measured as a function of its transverse momentum p(T). The cross-section in the fiducial region 0 < p(T) < 12 GeV/c and rapidity 2.0 < y < 4.5 is measured to be 5.6 +/- 0.1 (stat) +/- 0.4 (syst) mu b, with the assumption of unpolarised J/psi production. The fraction of J/psi production from b-hadron decays is measured to be (7.1 +/- 0.6 (stat) +/- 0.7 (syst))%.
Olivier Schneider, Aurelio Bay, Guido Haefeli, Tatsuya Nakada, Frédéric Blanc, Lesya Shchutska, Elena Graverini, Sebastian Schulte, Donal Patrick Hill, Marie Theres Christin Bachmayer, Serhii Cholak, Veronica Sølund Kirsebom, Ettore Zaffaroni, Surapat Ek-In, Aravindhan Venkateswaran, Sara Celani, Renato Quagliani, Luis Miguel Garcia Martin, Vitalii Lisovskyi, Elisabeth Maria Niel, Federico Ronchetti, Radoslav Marchevski, Anni Matilda Kauniskangas, Dimitrios Kaminaris, Raphaël van Laak, Pierre Paul Louis Mayencourt, Brianna Leililani Thielen, Yifei Song
Jian Wang, Matthias Finger, Qian Wang, Yiming Li, João Miguel das Neves Duarte, Matthias Wolf, Varun Sharma, Yi Zhang, Tian Cheng, Yixing Chen, Alexis Kalogeropoulos, Ioannis Papadopoulos, Hua Zhang, Siyuan Wang, Xin Chen, Michele Bianco, Sebastiana Gianì, Sun Hee Kim, Davide Di Croce, Jian Zhao, Rakesh Chawla, Jan Steggemann, Konstantin Androsov, Anna Mascellani, Federica Legger, Matteo Galli, Gabriele Grosso