J/ψ Polarization in pp Collisions at s=7TeV
Abstract
The ALICE Collaboration has studied J/ψ production in pp collisions at s=7TeV at the LHC through its muon pair decay. The polar and azimuthal angle distributions of the decay muons were measured, and results on the J/ψ polarization parameters λθ and λϕ were obtained. The study was performed in the kinematic region 2.5<y<4, 2<pt<8GeV/c, in the helicity and Collins-Soper reference frames. In both frames, the polarization parameters are compatible with zero, within uncertainties.
- Publication:
-
Physical Review Letters
- Pub Date:
- February 2012
- DOI:
- 10.1103/PhysRevLett.108.082001
- arXiv:
- arXiv:1111.1630
- Bibcode:
- 2012PhRvL.108h2001A
- Keywords:
-
- 13.88.+e;
- 13.20.Gd;
- 13.85.Qk;
- Polarization in interactions and scattering;
- Decays of J/psi Upsilon and other quarkonia;
- Inclusive production with identified leptons photons or other nonhadronic particles;
- High Energy Physics - Experiment
- E-Print:
- 15 pages, 3 captioned figures, 1 table, authors from page 10, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/3503