The polarizations of prompt J/psi and psi(2S) mesons are measured in proton-proton collisions at root s = 7 TeV, using a dimuon data sample collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 4.9 fb(-1). The prompt J/psi and psi(2S) polarization parameters lambda, lambda, and lambda, as well as the frame-invariant quantity (lambda) over bar. are measured from the dimuon decay angular distributions in three different polarization frames. The J/psi results are obtained in the transverse momentum range 14 < P-T < 70 GeV, in the rapidity intervals |y| < 0.6 and 0.6 < |y| < 1.2. The corresponding psi(2S) results cover 14 < PT < 50 GeV and include a third rapidity bin, 1.2 < |y| < 1.5. No evidence of large polarizations is seen in these kinematic regions, which extend much beyond those previously explored. (C) 2013 CERN. Published by Elsevier B.V. All rights reserved.
Measurement of the prompt J/ψ and ψ(2S) polarizations in pp collisions at √s=7 TeV
CIOCCI, MARIA AGNESE;MARTINI, LUCA;MESSINEO, ALBERTO MARIA;RIZZI, ANDREA;TONELLI, GUIDO EMILIO;L. Bianchini;A. C. Marini;
2013-01-01
Abstract
The polarizations of prompt J/psi and psi(2S) mesons are measured in proton-proton collisions at root s = 7 TeV, using a dimuon data sample collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 4.9 fb(-1). The prompt J/psi and psi(2S) polarization parameters lambda, lambda, and lambda, as well as the frame-invariant quantity (lambda) over bar. are measured from the dimuon decay angular distributions in three different polarization frames. The J/psi results are obtained in the transverse momentum range 14 < P-T < 70 GeV, in the rapidity intervals |y| < 0.6 and 0.6 < |y| < 1.2. The corresponding psi(2S) results cover 14 < PT < 50 GeV and include a third rapidity bin, 1.2 < |y| < 1.5. No evidence of large polarizations is seen in these kinematic regions, which extend much beyond those previously explored. (C) 2013 CERN. Published by Elsevier B.V. All rights reserved.File | Dimensione | Formato | |
---|---|---|---|
PHYSLetB_727_381.pdf
accesso aperto
Tipologia:
Versione finale editoriale
Licenza:
Creative commons
Dimensione
800.99 kB
Formato
Adobe PDF
|
800.99 kB | Adobe PDF | Visualizza/Apri |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.