@article{2e9e058e236542129d30995e60623344,
title = "J/ψ polarization in p+p collisions at s=200 GeV in STAR",
abstract = "We report on a polarization measurement of inclusive J/ψ mesons in the di-electron decay channel at mid-rapidity at 2 < pT < 6 GeV/c in p + p collisions at √s = 200 GeV. Data were taken with the STAR detector at RHIC. The J/ψ polarization measurement should help to distinguish between the different models of the J/ψ production mechanism since they predict different pT dependences of the J/ψ polarization. In this analysis, J/ψ polarization is studied in the helicity frame. The polarization parameter λθ measured at RHIC becomes smaller towards high pT , indicating more longitudinal J/ψ polarization as pT increases. The result is compared with predictions of presently available models.",
author = "{STAR Collaboration} and L. Adamczyk and Adkins, {J. K.} and G. Agakishiev and Aggarwal, {M. M.} and Z. Ahammed and I. Alekseev and J. Alford and Anson, {C. D.} and A. Aparin and D. Arkhipkin and Aschenauer, {E. C.} and Averichev, {G. S.} and J. Balewski and A. Banerjee and Z. Barnovska and Beavis, {D. R.} and R. Bellwied and A. Bhasin and Bhati, {A. K.} and P. Bhattarai and H. Bichsel and J. Bielcik and J. Bielcikova and Bland, {L. C.} and Bordyuzhin, {I. G.} and W. Borowski and J. Bouchet and Brandin, {A. V.} and Brovko, {S. G.} and S. B{\"u}ltmann and I. Bunzarov and Burton, {T. P.} and J. Butterworth and H. Caines and {Calder{\'o}n De La Barca S{\'a}nchez}, M. and D. Cebra and R. Cendejas and Cervantes, {M. C.} and P. Chaloupka and Z. Chang and S. Chattopadhyay and Chen, {H. F.} and Chen, {J. H.} and L. Chen and J. Cheng and M. Cherney and A. Chikanian and W. Christie and J. Chwastowski and {Derradi De Souza}, R.",
year = "2014",
month = dec,
day = "2",
doi = "10.1016/j.physletb.2014.10.049",
language = "English (US)",
volume = "739",
pages = "180--188",
journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",
issn = "0370-2693",
publisher = "Elsevier B.V.",
}