Compact Muon Solenoid
LHC, CERN
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| CMS-BPH-11-023 ; CERN-PH-EP-2012-205 | ||
| Measurement of the $\Upsilon (1S)$, $\Upsilon (2S) $ and $\Upsilon (3S) $ polarizations in pp collisions at $\sqrt{s}$ = 7 TeV | ||
| CMS Collaboration | ||
| 14 September 2012 | ||
| Phys. Rev. Lett. 110 (2013) 081802 | ||
| Abstract: The polarizations of the Y(1S), Y(2S), and Y(3S) mesons are measured in proton-proton collisions at $\sqrt{s}$ = 7 TeV, using a data sample of Y(nS) to oppositely charged muon pair decays collected by the CMS experiment, corresponding to an integrated luminosity of 4.9 inverse femtobarns. The dimuon decay angular distributions are analyzed in three different polarization frames. The polarization parameters lambda[theta], lambda[phi], and lambda[theta,phi], as well as the frame-invariant quantity lambda-tilde, are presented as a function of the Y(nS) transverse momentum between 10 and 50 GeV, in the rapidity ranges abs(y) < 0.6 and 0.6 < abs(y) < 1.2. No evidence of large transverse or longitudinal polarizations has been seen in the explored kinematic region. | ||
| Links: e-print arXiv:1209.2922 [hep-ex] (PDF) ; CDS record ; inSPIRE record ; Public twiki page ; HepData record ; CADI line (restricted) ; | ||
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Compact Muon Solenoid LHC, CERN |
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