Kinematic distributions and nuclear effects of J/ψ production in 920 GeV fixed-target proton-nucleus collisions

Abstract

Measurements of the kinematic distributions of J /ψ mesons produced in p-C, p-Ti and p-W collisions at √ s = 41.6 GeV in the Feynman-x region −0.34 < x F < 0.14 and for transverse momentum up to p T = 5.4 GeV/c are presented. The x F and p T dependencies of the nuclear suppression parameter, α, are also given. The results are based on 2.4 × 10 5 J /ψ mesons reconstructed in both the e + e − and μ + μ − decay channels. The data have been collected by the HERA-B experiment at the HERA proton ring of the DESY laboratory. The measurement explores the negative region of x F for the first time. The average value of α in the measured x F region is 0.981 ± 0.015. The data suggest that the strong nuclear suppression of J /ψ production previously observed at high x F turns into an enhancement at negative x F .

Study of ψ(2S) production and cold nuclear matter effects in pPb collisions at s N N = 5 $$ \sqrt{s_{N\;N}}=5 $$ TeV

“…The suppression of quarkonium and light hadrons at large rapidity has been observed in pA collisions [10][11][12][13] and in deuteron-gold collisions [14][15][16][17][18]. The proton-lead (pPb) collisions recorded at the LHC in 2013 enable the study of CNM effects at the TeV scale.…”

Centrality dependence of inclusive J/ψ production in p-Pb collisions at s N N = 5.02 $$ \sqrt{s_{\mathrm{NN}}}=5.02 $$ TeV

“…The J/ψ production in proton-or deuteron-nucleus collisions was studied at fixedtarget (SPS [37,38], HERA [39], Tevatron [40]) and collider experiments (RHIC [41], LHC [42][43][44][45]). At the LHC, a suppression of the J/ψ production in p-Pb collisions with respect to binary-scaled pp production has been observed for p T < 5 GeV/c at large rapidity in the p-going direction and at mid-rapidity, while the measurements at high p T as well as at large rapidity in the Pb-going direction are consistent with no suppression.…”

“…The differential results also indicate a smaller degree of suppression at p T < 3 GeV/c than at higher p T [33,34], at mid-and forward rapidity, in agreement with the expectations from (re)combination models [35,36]. Although, qualitatively, the Pb-Pb measurements by themselves give a strong indication that the (re)combination effect plays a significant role in the J/ψ production at LHC energies, the quantitative understanding of the involved mechanisms requires a good knowledge of the underlying CNM effects.The J/ψ production in proton-or deuteron-nucleus collisions was studied at fixedtarget (SPS [37,38], HERA [39], Tevatron [40]) and collider experiments (RHIC [41], LHC [42][43][44][45]). At the LHC, a suppression of the J/ψ production in p-Pb collisions with respect to binary-scaled pp production has been observed for p T < 5 GeV/c at large rapidity in the p-going direction and at mid-rapidity, while the measurements at high p T as well as at large rapidity in the Pb-going direction are consistent with no suppression.…”

Impact-parameter dependence of the nuclear modification ofJ/ψproduction ind+Au collisions atsNNMcGlinchey1, Frawley2, Vogt3 2013Phys. Rev. C653740View full textAdd to dashboardCite

“…The fixed target p + A data used in in Ref. [12] were from E866 at 800 GeV [23]; HERA-B at 920 GeV [24]; NA50 at 400 GeV [25] and 450 GeV [26]; and NA3 at 200 GeV [27]. Those for NA60 at 158 GeV were extracted in [28].…”