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



Acharya, S, Acosta, F-T, Adamova, D, Adolfsson, J, Aggarwal, MM, Rinella, G Aglieri, Agnello, M, Agrawal, N, Ahammed, Z, Ahn, SU
et al (show 1003 more authors) (2018) Measurement of the inclusive J/psi polarization at forward rapidity in pp collisions at root s=8 TeV. EUROPEAN PHYSICAL JOURNAL C, 78 (7). 562-.

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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.

Item Type: Article
Depositing User: Symplectic Admin
Date Deposited: 07 May 2019 10:57
Last Modified: 14 Mar 2024 21:18
DOI: 10.1140/epjc/s10052-018-6027-2
Open Access URL: https://doi.org/10.1140/epjc/s10052-018-6027-2
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URI: https://livrepository.liverpool.ac.uk/id/eprint/3040072