We have measured the differential cross section for the inclusive production of psi(2S) mesons decaying to mu^{+} mu^{-1} that were produced in prompt or B-decay processes from ppbar collisions at 1.96 TeV. These measurements have been made using a data set from an integrated luminosity of 1.1 fb^{-1} collected by the CDF II detector at Fermilab. For events with transverse momentum p_{T} (psi(2S)) > 2 GeV/c and rapidity |y(psi(2S))| < 0.6 we measure the integrated inclusive cross section sigma(ppbar -> psi(2S)X) Br(psi(2S) -> mu^{+} mu^{-}) to be 3.29 +- 0.04(stat.) +- 0.32(syst.) nb.
The differential cross section times the dimuon branching fraction as a function of pT.
The integrated inclusive differential cross section for PSI(3685).
The product of the photoproduction cross section at 11.1 GeV for ψ(3105) on nucleons times the branching ratio for ψ into e+e− is less than 75 pb, at the 90% confidence level. This result implies a ψ-nucleon total cross section of less than 1.2 mb.
The branching ratio for J/PSI --> E+ E- is taken as 0.06.
We present a measurement of the cross section for hadron production by e+e− annihilation in the vicinity of the previously observed resonance near 3.77 GeV. The data are used to determine the parameters of the ψ(3770) resonance. The values found are: mass, 3764±5 MeV/c2, total width, 23.5±5 MeV, and partial width to electron pairs, 276±50 eV.
THESE RESULTS ARE ALSO IN THE THESIS OF R. H. SCHINDLER, SLAC-219 (1979), THE RECORD OF WHICH CONTAINS THE TABULATED CROSS SECTIONS.
BREIT-WIGNER RESONANCE PLUS BACKGROUND FIT TO RADIATIVELY CORRECTED DATA YIELDS RESONANCE MASS OF 3764 +- 5 MEV, TOTAL WIDTH OF 23.5 +- 5 MEV AND PARTIAL WIDTH TO ELECTRON PAIRS OF 276 +- 50 EV.
PEAK CROSS SECTION FOR D MESON PAIR PRODUCTION AT PSI(3770) RESONANCE. J/PSI, PSI(3684) AND CONTINUUM BACKGROUND (R=2.5) SUBTRACTED.
We have measured the inclusive production of J ψ in 16 and 22 GeV π − copper collisions in a wide aperture magnetic spectrometer. The cross section per Cu nucleus for x > 0 corrected for branching ratio is 64 ± 38 nb at 16 GeV and 196 ± 38 nb at 22 GeV. As threshold is approached, the mean values of the Feynman x distribution increase and the cross section for J ψ production drops steeply. This can be understood in terms of the quark-fusion model where the antiquark content of the pion makes an increasingly significant contribution as M 2 s increases.
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The observation of an anomalous J/ ψ suppression in Pb–Pb collisions by the NA50 Collaboration can be considered as the most striking indication for the deconfinement of quarks and gluons at SPS energies. In this Letter, we determine the J/ ψ suppression pattern as a function of the forward hadronic energy E ZDC measured in a Zero Degree Calorimeter (ZDC). The direct connection between E ZDC and the geometry of the collision allows us to calculate, within a Glauber approach, the precise relation between the number of participant nucleons N part and E ZDC . Then, we check if the experimental data can be better explained by a sudden or a smooth onset of the anomalous J/ ψ suppression as a function of the number of participants.
Minimum Bias E(C=ZDC) spectrum. Data extracted from fig with g3data, statistical errors not included and are set to 0, the systematic errors given by g3data due to extraction.
Number of participants as a function of E(C=ZDC) Data exctracted from fig with g3data, the systematic errors given by g3data due to extraction, and those marked (stat) are in this case the r.m.s. of the Npart distribution at fixed E(C=ZDC).;.
SIG(J/PSI)/SIG(DY) as a function of E(C=ZDC) with the standard analyses of the 1996 DATA 1996, standard analyses.
The analysis of the data collected by the NA50 experiment in 1998, reported in this paper, extends and clarifies the pattern of the previously observed J/ ψ anomalous suppression. This new measurement, besides providing a deeper understanding of the previous observations, reveals a steady significative decrease in the J/ ψ production rate up to the most central Pb-Pb collisions. It clearly rules out the presently available conventional (hadronic) models of J/ ψ suppression, which unanimously predict a saturation of the J/ ψ rate for central Pb-Pb collisions. On the contrary and together with the sharp onset of the anomalous suppression previously reported, the new observation leads to a global production rate pattern which finds its natural explanation in the framework of the formation of a deconfined state of quarks and gluons.
SIG(J/PSI)/SIG(DY) as a function of ET with the standard analyses of 1996. DATA 1996, standard analyses.
SIG(J/PSI)/SIG(DY) as a function of ET with the minium bias analyses of 1996. DATA 1996, MB Analyses.
SIG(J/PSI)/SIG(DY) as a function of E(NAME=TRANSVERSE) with the minium bias analyses of 1998. DATA 1998, MB Analyses.
Muon pairs produced in Pb–Pb interactions at 158 GeV/ c per nucleon are used to study the transverse momentum distributions of the J/ ψ , ψ ′ and dimuons in the mass continuum. In particular, the dependence of these distributions on the centrality of the Pb–Pb collision is investigated in detail.
Mean values of PT and PT**2 calculated from the IMR distributions.
Mean values of PT and PT**2 calculated from the J/PSI distributions.
Mean values of PT and PT**2 calculated from the PSI(3685) distributions.
We report a new measurement of J/psi, psi' and Drell-Yan cross-sections, in the kinematical domain $-0.425<y_{\rm cm}<0.575$ and $-0.5<\cos\theta_{\rm CS}<0.5$, performed at the CERN-SPS using 400 GeV/c incident protons on Be, Al, Cu, Ag, W and Pb targets. The dependence of the charmonia production cross-sections on the size of the target nucleus allows to quantify the so-called normal nuclear absorption. In the framework of the Glauber model, this new measurement is combined with results previously obtained with the same apparatus, under different experimental conditions, and leads to a precise determination of the J/psi and psi' absorption cross-sections in the surrounding nuclear matter.
Production cross sections, per taregt nucleon for J/PSI and PSI(3685) and for Drell-Yann dimuon in the mass range of 2.9-4.5 GeV/c**, integrated in the phase space windows of the measurement.
Ratios of J/PSI, PSI(3685) and Drel Yann production cross sections, and for Drell-Yann dimuon in the mass range of 2.9-4.5 GeV/c**, integrated in the phase space windows of the measurement.
Absorption cross-section obtained with Glauber fits results only from this analysis.
First results on charm quarkonia production in heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) are presented. The yield of J/Psi's measured in the PHENIX experiment via electron-positron decay pairs at mid-rapidity for Au-Au reactions at sqrt(s_NN) = 200 GeV are analyzed as a function of collision centrality. For this analysis we have studied 49.3 million minimum bias Au-Au reactions. We present the J/Psi invariant yield dN/dy for peripheral and mid-central reactions. For the most central collisions where we observe no signal above background, we quote 90% confidence level upper limits. We compare these results with our J/Psi measurement from proton-proton reactions at the same energy. We find that our measurements are not consistent with models that predict strong enhancement relative to binary collision scaling.
Measured invariant differential yield at mid-rapidity of J/PSI, as a function of centratility, times branching ratio Be+e-, for three bins of centrality : 0-20%, 20-40% and 40-90% of Au-Au cross-section. The 90% confidence level upper limit (CLUL) for the yield is also given.
Measured differential yield of J/PSI per binary collisions,at mid rapidity, as a function of the centrality, times branching ratio Be+e-.The 90% confidence level upper limit (CLUL) for J/PSI differential yield is also given. The values of the number of participants for each centrality bins are calculated for general information.
We report the first observation of diffractive $J/\psi(\to \mu^+\mu^-)$ production in $\bar pp$ collisions at $\sqrt{s}$=1.8 TeV. Diffractive events are identified by their rapidity gap signature. In a sample of events with two muons of transverse momentum $p_T^{\mu}>2$ GeV/$c$ within the pseudorapidity region $|\eta|<$1.0, the ratio of diffractive to total $J/\psi$ production rates is found to be $R_{J/\psi}= [1.45\pm 0.25]%$. The ratio $R_{J/\psi}(x)$ is presented as a function of $x$-Bjorken. By combining it with our previously measured corresponding ratio $R_{jj}(x)$ for diffractive dijet production, we extract a value of $0.59\pm 0.15$ for the gluon fraction of the diffractive structure function of the proton.
Diffractive to total J/psi production ratio.
Ratio of diffractive to total J/psi rate, per unit of the fractional momentum loss of the leading (anti)proton, and as a function of x-Bjorken of the struck parton of the (anti)proton adjacent to the rapidity gap and participating in the J/psi production.
Gluon fraction of the diffractive structure function of the (anti)proton.
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