TY - JOUR
T1 - Measurement of the inclusive J/psi polarization at forward rapidity in pp collisions at root s=8 TeV
AU - Acharya, S.
AU - Acosta, F
AU - Adamova, D.
AU - Adolfsson, Jan
AU - Aggarwal, MM.
AU - Rinella, G.A.
AU - Agnello, Maria
AU - Agrawal, N.
AU - Ahammed, Z.
AU - Ahn, S.U.
AU - Aiola, S.
AU - Akindinov, A.
AU - Al-Turany, M.
AU - Alam, SN
AU - Albuquerque, DSD
AU - Aleksandrov, D.
AU - Alessandro, B
AU - Bearden, Ian
AU - Bilandzic, Ante
AU - Pimentel, Lais Ozelin de Lima
AU - Bourjau, Christian Alexander
AU - Gaardhøje, Jens Jørgen
AU - Chojnacki, Marek
AU - Thoresen, Freja
AU - Nielsen, Børge Svane
AU - bsm989, bsm989
AU - Pacik, Vojtech
AU - Vislavicius, Vytautas
AU - Zhou, You
AU - Gajdosova, Katarina
AU - rtc312, rtc312
PY - 2018/7/1
Y1 - 2018/7/1
N2 - 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, λθ φ) 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.
AB - 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, λθ φ) 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.
U2 - 10.1140/epjc/s10052-018-6027-2
DO - 10.1140/epjc/s10052-018-6027-2
M3 - Journal article
SN - 1434-6044
VL - 78
JO - European Physical Journal C
JF - European Physical Journal C
IS - 7
M1 - 562
ER -