# Measurement of the transverse polarization of $\Lambda$ and $\bar{\Lambda}$ hyperons produced in proton--proton collisions at $\sqrt{s}=7$ TeV using the ATLAS detector

Abstract : 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.
Type de document :
Article dans une revue
Physical Review D, American Physical Society, 2015, 91, pp.032004. 〈10.1103/PhysRevD.91.032004〉

http://hal.in2p3.fr/in2p3-01091281
Contributeur : Emmanuelle Vernay <>
Soumis le : vendredi 5 décembre 2014 - 09:26:26
Dernière modification le : mardi 13 février 2018 - 13:28:06

### Citation

G. Aad, S. Albrand, J. Brown, J. Collot, S. Crépé-Renaudin, et al.. Measurement of the transverse polarization of $\Lambda$ and $\bar{\Lambda}$ hyperons produced in proton--proton collisions at $\sqrt{s}=7$ TeV using the ATLAS detector. Physical Review D, American Physical Society, 2015, 91, pp.032004. 〈10.1103/PhysRevD.91.032004〉. 〈in2p3-01091281〉

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