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- 1 collected 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/ ÏpT and 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/ Ï pair production cross-section in pp collisions at âs=8 TeV with the ATLAS detector
BARBERIS, DARIO;FAVARETO, ANDREA;GAGLIARDI, GUIDO;GAUDIELLO, ANDREA;GUIDO, ELISA;MIGLIORANZI, SILVIA;OSCULATI, BIANCA MARIA;PARODI, FABRIZIO;SANNINO, MARIO;SCHIAVI, CARLO;Sforza, F.;
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- 1 collected 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/ ÏpT and 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.