@article{oai:tsukuba.repo.nii.ac.jp:00040368,
 author = {PHENI Collaboration and Chujo, T. and 中條, 達也 and Esumi, S. and 江角, 晋一 and Miake, Y. and 三明, 康郎},
 issue = {11},
 journal = {Physical review D},
 month = {Dec},
 note = {We report the double-helicity asymmetry, AJ/ψLL, in inclusive J/ψ production at forward rapidity as a function of transverse momentum pT and rapidity |y|. The data analyzed were taken during √s=510 GeV longitudinally polarized p+p collisions at the Relativistic Heavy Ion Collider in the 2013 run using the PHENIX detector. At this collision energy, J/ψ particles are predominantly produced through gluon-gluon scatterings, thus AJ/ψLL is sensitive to the gluon polarization inside the proton. We measured AJ/ψLL by detecting the decay daughter muon pairs μ+μ- within the PHENIX muon spectrometers in the rapidity range 1.2<|y|<2.2. In this kinematic range, we measured the AJ/ψLL to be 0.012±0.010 (stat) ±0.003 (syst). The AJ/ψLL can be expressed to be proportional to the product of the gluon polarization distributions at two distinct ranges of Bjorken x: one at moderate range x≈5×10^-2 where recent data of jet and π^0 double helicity spin asymmetries have shown evidence for significant gluon polarization, and the other one covering the poorly known small-x region x≈2×10^-3. Thus our new results could be used to further constrain the gluon polarization for x<5×10^-2.},
 title = {Measurements of double-helicity asymmetries in inclusive J／ψ production in longitudinally polarized p+p collisions at √s=510 GeV},
 volume = {94},
 year = {2016},
 yomi = {エスミ, シンイチ and ミアケ, ヤスオ}
}