We report on the measurement of the inclusive J/ψ polarization parameters in pp collisions at a center of mass energy √s=8 TeV with the ALICE detector at the LHC. The analysis is based on a data sample corresponding to an integrated luminosity of 1.23 pb- 1. J/ψ resonances are reconstructed in their di-muon decay channel in the rapidity interval 2.5 < y< 4.0 and over the transverse-momentum interval 2 < pT< 15 GeV / c. The three polarization parameters (λθ, λφ, λθφ) are measured as a function of pT both in the helicity and Collins-Soper reference frames. The measured J/ψ polarization parameters are found to be compatible with zero within uncertainties, contrary to expectations from all available predictions. The results are compared with the measurement in pp collisions at √s = 7 TeV.

Acharya, S., Acosta, F., Adamová, D., Adolfsson, J., Aggarwal, M., Aglieri Rinella, G., et al. (2018). Measurement of the inclusive J/ ψ polarization at forward rapidity in pp collisions at √s=8 TeV. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 78(7), 1-16 [10.1140/epjc/s10052-018-6027-2].

Measurement of the inclusive J/ ψ polarization at forward rapidity in pp collisions at √s=8 TeV

Alici, A.;Arcelli, S.;Bellini, F.;Carnesecchi, F.;Cifarelli, L.;Colocci, M.;Jacazio, N.;Scioli, G.;
2018

Abstract

We report on the measurement of the inclusive J/ψ polarization parameters in pp collisions at a center of mass energy √s=8 TeV with the ALICE detector at the LHC. The analysis is based on a data sample corresponding to an integrated luminosity of 1.23 pb- 1. J/ψ resonances are reconstructed in their di-muon decay channel in the rapidity interval 2.5 < y< 4.0 and over the transverse-momentum interval 2 < pT< 15 GeV / c. The three polarization parameters (λθ, λφ, λθφ) are measured as a function of pT both in the helicity and Collins-Soper reference frames. The measured J/ψ polarization parameters are found to be compatible with zero within uncertainties, contrary to expectations from all available predictions. The results are compared with the measurement in pp collisions at √s = 7 TeV.
2018
Acharya, S., Acosta, F., Adamová, D., Adolfsson, J., Aggarwal, M., Aglieri Rinella, G., et al. (2018). Measurement of the inclusive J/ ψ polarization at forward rapidity in pp collisions at √s=8 TeV. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 78(7), 1-16 [10.1140/epjc/s10052-018-6027-2].
Acharya, S.; Acosta, F.-T.; Adamová, D.; Adolfsson, J.; Aggarwal, M.M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahn, S.U.; Aiola, ...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/664059
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