@article{0f566db81ba145b18bb3f2f70af889fd,
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.",
keywords = "Charmonia, Polarization, RHIC, STAR, Spin alignment",
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 S. Gliske",
note = "Funding Information: We thank the RHIC Operations Group and RCF at BNL , the NERSC Center at LBNL , the KISTI Center in Korea and the Open Science Grid consortium for providing resources and support. This work was supported in part by the Offices of NP and HEP within the U.S. DOE Office of Science , the U.S. NSF , CNRS/IN2P3 , FAPESP CNPq of Brazil , Ministry of Ed. and Sci. of the Russian Federation , NNSFC, CAS , MoST and MoE of China , the Korean Research Foundation , GA and MSMT of the Czech Republic , FIAS of Germany , DAE , DST , and CSIR of India , National Science Centre of Poland , National Research Foundation ( NRF-2012004024 ), Ministry of Sci., Ed. and Sports of the Rep. of Croatia , and RosAtom of Russia . Publisher Copyright: {\textcopyright} 2014 The Authors.",
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",
}