The production of two prompt J/ ψ mesons, each with transverse momenta pT> 8.5 GeV and rapidity |y| < 2.1 , is studied using a sample of proton-proton collisions at s=8 TeV, corresponding to an integrated luminosity of 11.4 fb- 1 collected in 2012 with the ATLAS detector at the LHC. The differential cross-section, assuming unpolarised J/ ψ production, is measured as a function of the transverse momentum of the lower-pTJ/ ψ meson, di-J/ ψpT and mass, the difference in rapidity between the two J/ ψ mesons, and the azimuthal angle between the two J/ ψ mesons. The fraction of prompt pair events due to double parton scattering is determined by studying kinematic correlations between the two J/ ψ mesons. The total and double parton scattering cross-sections are compared with predictions. The effective cross-section of double parton scattering is measured to be σeff= 6.3 ± 1.6 (stat) ± 1.0 (syst) mb. © 2017, CERN for the benefit of the ATLAS collaboration.
Measurement of the prompt J/ ψ pair production cross-section in pp collisions at √s=8 TeV with the ATLAS detector / Aloisio, A., Alviggi, M., Canale, V., Della Pietra, M., Merola, L., Giordano, R., Conventi, F., Rossi, E., Carlino, G., de Asmundis, R., Di Donato, C., Doria, A., Ra, ., Iengo, P., Izzo, V., Perrella, S., Sekhniaidze, G., Cirotto, F., Atlas, C.. - In: THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS. - ISSN 1434-6044. - 77:2(2017). [10.1140/epjc/s10052-017-4644-9]
Measurement of the prompt J/ ψ pair production cross-section in pp collisions at √s=8 TeV with the ATLAS detector
Aloisio, Alberto;Alviggi, MariaGrazia;Canale, Vincenzo;Della Pietra, Massimo;Merola, Leonardo;Giordano, Raffaele;Rossi, Elvira;de Asmundis, Riccardo;Izzo, Vincenzo;Perrella, Sabrina;Cirotto, Francesco;
2017
Abstract
The production of two prompt J/ ψ mesons, each with transverse momenta pT> 8.5 GeV and rapidity |y| < 2.1 , is studied using a sample of proton-proton collisions at s=8 TeV, corresponding to an integrated luminosity of 11.4 fb- 1 collected in 2012 with the ATLAS detector at the LHC. The differential cross-section, assuming unpolarised J/ ψ production, is measured as a function of the transverse momentum of the lower-pTJ/ ψ meson, di-J/ ψpT and mass, the difference in rapidity between the two J/ ψ mesons, and the azimuthal angle between the two J/ ψ mesons. The fraction of prompt pair events due to double parton scattering is determined by studying kinematic correlations between the two J/ ψ mesons. The total and double parton scattering cross-sections are compared with predictions. The effective cross-section of double parton scattering is measured to be σeff= 6.3 ± 1.6 (stat) ± 1.0 (syst) mb. © 2017, CERN for the benefit of the ATLAS collaboration.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.


