Auteur(s): Aad G., Albrand S., Brown J., Collot J., Crépé-Renaudin S., Dechenaux B., Delsart P.A., Gabaldon C., Genest M.H., Hostachy J.Y., Ledroit-Guillon F., Lleres A., Lucotte A., Malek F., Monini C., Stark J., Trocmé B., Wu M., Rahal G., Barnovska Z., Berger N., Delmastro M., Ciaccio L. Di, Elles S., Goy C., Hryn’ova T., Jézéquel S., Keoshkerian H., Koletsou I., Ughetto M.
(Article) Publié:
Physical Review D, vol. 91 p.032004 (2015)
Texte intégral en Openaccess : 
Ref Arxiv: 1412.1692
DOI: 10.1103/PhysRevD.91.032004
WoS: 000349487000001
Ref. & Cit.: NASA ADS
11 Citations
Résumé:
The transverse polarization of $\Lambda$ and $\bar\Lambda$ hyperons produced in proton-proton collisions at a center-of-mass energy of 7 TeV is measured. The analysis uses 760 $\mu$b$^{-1}$ of minimum bias data collected by the ATLAS detector at the LHC in the year 2010. The measured transverse polarization averaged over Feynman $x_{\rm F}$ from $5\times 10^{-5}$ to 0.01 and transverse momentum $p_{\rm T}$ from 0.8 to 15 GeV is $-0.010 \pm 0.005({\rm stat}) \pm 0.004({\rm syst})$ for $\Lambda$ and $0.002 \pm 0.006({\rm stat}) \pm 0.004({\rm syst})$ for $\bar\Lambda$. It is also measured as a function of $x_{\rm F}$ and $p_{\rm T}$, but no significant dependence on these variables is observed. Prior to this measurement, the polarization was measured at fixed-target experiments with center-of-mass energies up to about 40 GeV. The ATLAS results are compatible with the extrapolation of a fit from previous measurements to the $x_{\rm F}$ range covered by this mesurement.
Commentaires: See paper for full list of authors – 10 pages plus author list + cover pages (23 pages total), 8 figures, 3 tables, submitted to Phys. Rev. D, All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2011-45/