Measurement ofJ/ψ and ψ’ production in 800 GeV/cproton-gold collisions

Abstract

With a data sample containing 1.1 x lo5 J/$ -+ /L+/L-decays reconstructed with 16 M~V / C ' rms mass resolution, we have measured the differential cross sections versus Feynman-x, rapidity, and p~ for the production of J/$ and 4' in 800 GeVlc p A u collisions. Our results are compared with leading-order QCD predictions and with previous measurements. While the shapes of the cross sections are in qualitative agreement with QCD predictions, the magnitudes disagree by factors of 7 ( J / 4 ) and 25 (4'). Assuming an appropriate form for the differential cross sections in regions not measured, we derive a total J/+ production cross section a ( p + N + J/$ + X) = 442 f 2 i 88 nb/nucleon and a (model-dependent) total 4' cross section u(p + N + $' + X) = 75 f 5 f 22 nblnucleon. For J/$ produced at central rapidity, du(p + N + J/$ + X)/dyly=o = 230 i 5 f 46 nb/nucleon. PACS number(s): 13.85. Ni, 24.85.+p, 25.40.Ve

J/ψsuppression at forward rapidity in Au+Au collisions atsNNAdare1, Aidala2, Ajitanand3 et al. 2012Phys. Rev. CSelf Cite352230View full textAdd to dashboardCite

“…Fermilab fixed target experiment E789 [34,35] has measured the invariant cross sections of J/ψ in p+Be, p+Cu, and p+Au collisions over a broad rapidity range at √ s N N = 38.8 GeV. The rapidity coverage for p+Au was −0.1 < y < +0.7; and for p+Be and p+Cu was 1.4 < y < 2.4.…”

Ground and excited state charmonium production inp+pcollisions ats=200 GeV

“…An empirical description of the J/ψ yield used in some fixed-target experiments with large coverage [56][57][58][59][60][61][62][63] is based on the Feynman x F form [63],…”

“…This extrapolation of the rapidity dependence can be used to estimate the total cross section from measurements with limited rapidity coverage and will be used as one method to calculate the total cross section from the present measurement. [56][57][58][59][60][61][62][63] and in the PHENIX rapidity distribution. The parameters (a = 27.5 ± 1.8, b = (141 ± 11) GeV) are obtained from a fit to the experimental data points.…”

Open and hidden charm production in 920 GeV proton-nucleus collisions

“…In Table 1, preliminary HERA-B results on p T are shown. The comparison of different target materials and with results of the experiments E771 [1] and E789 [2] shows an increase of p T with the atomic mass number. Transverse momentum distribution dN/dp T 2 of J/ψ → e + e − decays.…”