Naslov
Measurement of prompt J/ψ pair production in pp collisions at √s = 7 Tev

Autori
Khachatryan, V. ; ... ; Pleština, Roko ; ... ; Godinović, Nikola ; Lelas, Damir ; Pleština, Roko ; Polić, Dunja ; Puljak, Ivica ; Antunović, Željko ; Kovač, Marko ; Brigljević, Vuko ; Kadija, Krešo ; Luetić, Jelena ; Mekterović, Darko ; Morović, Srećko ; Sudić, Lucija ; ... ; Đurić, Senka ; ... ; Woods, N.

Izvornik
Journal of High Energy Physics (1029-8479) 1409 (2014); 094-1

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Hadron-Hadron Scattering; B physics

Sažetak
Production of prompt J/ψ meson pairs in proton- proton collisions at √ s = 7 TeV is measured with the CMS experiment at the LHC in a data sample corresponding to an integrated luminosity of about 4.7 fb−1 . The two J/ψ mesons are fully reconstructed via their decays into µ +µ − pairs. This observation provides for the first time access to the high-transverse-momentum region of J/ψ pair production where model predictions are not yet established. The total and differential cross sections are measured in a phase space defined by the individual J/ψ transverse momentum (pT J/ψ) and rapidity (|y J/ψ|): |y J/ψ| < 1.2 for p J/ψ T > 6.5 GeV/c ; 1.2 < |y J/ψ| < 1.43 for a pT threshold that scales linearly with |y J/ψ| from 6.5 to 4.5 GeV/c ; and 1.43 < |y J/ψ| < 2.2 for p J/ψ T > 4.5 GeV/c. The total cross section, assuming unpolarized prompt J/ψ pair production is 1.49 ± 0.07 (stat) ± 0.13 (syst) nb. Different assumptions about the J/ψ polarization imply modifications to the cross section ranging from −31% to +27%.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA