Abstract: Production of prompt J/? meson pairs in proton-proton collisions at vs = 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/? 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/? 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/? transverse momentum (pTJ/?) and rapidity (|yJ/?|): |yJ/? | < 1.2 for pTJ/? > 6.5 GeV/c; 1.2 < |yJ/?| < 1.43 for a pT threshold that scales linearly with |yJ/?| from 6.5 to 4.5 GeV/c; and 1.43 < |yJ/?| < 2.2 for pTJ/? > 4.5 GeV/c. The total cross section, assuming unpolarized prompt J/? pair production is 1.49 ± 0.07 (stat) ±0.13 (syst) nb. Different assumptions about the J/? polarization imply modifications to the cross section ranging from -31% to +27%.

Autoría

Descargar referencia