The production of two prompt J/ Ï 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- 1collected in 2012 with the ATLAS detector at the LHC. The differential cross-section, assuming unpolarised J/ Ï production, is measured as a function of the transverse momentum of the lower-pTJ/ Ï meson, di-J/ ÏpTand mass, the difference in rapidity between the two J/ Ï mesons, and the azimuthal angle between the two J/ Ï mesons. The fraction of prompt pair events due to double parton scattering is determined by studying kinematic correlations between the two J/ Ï 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 Ïeff= 6.3 ± 1.6 (stat) ± 1.0 (syst) mb.
Measurement of the prompt J/ Psi pair production cross-section in pp collisions at sqrt s=8 TeV with the ATLAS detector
Conventi, F.;Di Donato, C.;Rossi, E.;
2017-01-01
Abstract
The production of two prompt J/ Ï 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- 1collected in 2012 with the ATLAS detector at the LHC. The differential cross-section, assuming unpolarised J/ Ï production, is measured as a function of the transverse momentum of the lower-pTJ/ Ï meson, di-J/ ÏpTand mass, the difference in rapidity between the two J/ Ï mesons, and the azimuthal angle between the two J/ Ï mesons. The fraction of prompt pair events due to double parton scattering is determined by studying kinematic correlations between the two J/ Ï 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 Ïeff= 6.3 ± 1.6 (stat) ± 1.0 (syst) mb.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.