De Lesquen, A.
SIG/SIG
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Cross-sections of large-angle hadron production in proton- and pion-nucleus interactions VII: tin nuclei and beam momenta from \pm3 GeV/c to \pm15 GeV/c

Bolshakova, A. ; Boyko, I. ; Chelkov, G. ; et al.
Eur.Phys.J.C 71 (2011) 1719, 2011.
Inspire Record 899230 DOI 10.17182/hepdata.60575

We report on double-differential inclusive cross-sections of the production of secondary protons, charged pions, and deuterons, in the interactions with a 5% nuclear interaction length thick stationary tin target, of proton and pion beams with momentum from \pm3 GeV/c to \pm15 GeV/c. Results are given for secondary particles with production angles between 20 and 125 degrees. Cross-sections on tin nuclei are compared with cross-sections on beryllium, carbon, copper, tantalum and lead nuclei.

365 data tables
Table 1

Ratio of deuterons to protons for polar angle 20-30 deg.

Table 2

Ratio of deuterons to protons for polar angle 30-45 deg.

Table 3

Ratio of deuterons to protons for polar angle 45-65 deg.

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Cross-sections of large-angle hadron production in proton- and pion-nucleus interactions VI: carbon nuclei and beam momenta from \pm 3 GeV/c to \pm 15 GeV/c

The HARP-CDP collaboration Bolshakova, A. ; Boyko, I. ; Chelkov, G. ; et al.
Eur.Phys.J.C 70 (2010) 573-633, 2010.
Inspire Record 863735 DOI 10.17182/hepdata.55450

We report on double-differential inclusive cross-sections of the production of secondary protons, charged pions, and deuterons, in the interactions with a 5% nuclear interaction length thick stationary carbon target, of proton and pion beams with momentum from \pm 3 GeV/c to \pm 15 GeV/c. Results are given for secondary particles with production angles between 20 and 125 degrees. Cross-sections on carbon nuclei are compared with cross-sections on beryllium, copper, tantalum and lead nuclei.

365 data tables
Table 1

The measured deuteron to proton ratios for each of the 8 GeV Proton, PI+ and PI- beams for the angular range 20 to 30 degrees.

Table 2

The measured deuteron to proton ratios for each of the 8 GeV Proton, PI+ and PI- beams for the angular range 30 to 45 degrees.

Table 3

The measured deuteron to proton ratios for each of the 8 GeV Proton, PI+ and PI- beams for the angular range 45 to 60 degrees.

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J/psi production in Indium-Indium collisions at 158 GeV/nucleon

The NA60 collaboration Arnaldi, R. ; Banicz, K. ; Castor, J. ; et al.
Conf.Proc.C 060726 (2006) 430-434, 2006.
Inspire Record 754305 DOI 10.17182/hepdata.57244

The NA60 experiment studies muon pair production at the CERN SPS. In this letter we report on a precision measurement of J/psi in In-In collisions. We have studied the J/psi centrality distribution, and we have compared it with the one expected if absorption in cold nuclear matter were the only active suppression mechanism. For collisions involving more than ~80 participant nucleons, we find that an extra suppression is present. This result is in qualitative agreement with previous Pb-Pb measurements by the NA50 experiment, but no theoretical explanation is presently able to coherently describe both results.

1 data table
Table 1

Values of the J/PSI production cross section, divided by the Drell-Yann cross section, as a function of centrality. Centrality is determined by the amount of energy collectedby the zero degree calorimeter (ZDC), and the average nuber of participants, obtained from E(ZDC) is also given. (High E(ZDC) corresponds to peripheral events and low number of participants, and vice-versa) The values are uncorrected for the J/PSI decay branching ratio.


A new measurement of J/psi suppression in Pb-Pb collisions at 158 GeV per nucleon

The NA50 collaboration Alessandro, B. ; Alexa, C. ; Arnaldi, R. ; et al.
Eur.Phys.J.C 39 (2005) 335-345, 2005.
Inspire Record 667013 DOI 10.17182/hepdata.57372

We present a new measurement of J/psi production in Pb-Pb collisions at 158 GeV/nucleon, from the data sample collected in year 2000 by the NA50 Collaboration, under improved experimental conditions with respect to previous years. With the target system placed in vacuum, the setup was better adapted to study, in particular, the most peripheral nuclear collisions with unprecedented accuracy. The analysis of this data sample shows that the (J/psi)/Drell-Yan cross-sections ratio measured in the most peripheral Pb-Pb interactions is in good agreement with the nuclear absorption pattern extrapolated from the studies of proton-nucleus collisions. Furthermore, this new measurement confirms our previous observation that the (J/psi)/Drell-Yan cross-sections ratio departs from the normal nuclear absorption pattern for semi-central Pb-Pb collisions and that this ratio persistently decreases up to the most central collisions.

15 data tables
Table 1

Centrality classes based on the transverse energy measurement Errors are rms values obtained with fit.

Table 2

Cross sections ratio J/PSI/Drell-Yan as a function of ET IN GEV obtained withthe ET Centrality estimator.

Table 3

Cross sections ratio J/PSI/Drell-Yan as a function of NPART obtained withthe ET Centrality estimator.

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Charmonium production in Pb Pb interactions at 158-GeV/c per nucleon.

The NA50 collaboration Ramello, Luciano ; Abreu, M.C. ; Alessandro, B. ; et al.
Nucl.Phys.A 638 (1998) 261-278, 1998.
Inspire Record 481874 DOI 10.17182/hepdata.36232

The NA50 collaboration has measured J/ψ , ψ′ and Drell Yan pair production in Pb Pb interactions at 158 GeV/ c per nucleon at the CERN SPS. Final results from the 1995 run and preliminary ones from the higher statistics 1996 run are presented. A anomalous J/ψ suppression (relative to the Drell-Yan process) has been observed with respect to the suppression pattern established in experiments NA38 and NA51 with proton, oxygen and sulfur beams. The 1996 data allow a detailed study of the suppression pattern in the Pb Pb sample itself, showing a discontinuity around an E T value (the neutral transverse electromagnetic energy) of 50 GeV. The ψ′ is also suppressed relative to Drell-Yan, with a pattern very similar to the one observed in S U collisions. Finally, the p T distributions of dimuons are presented. The average p T 2 of the J/ψ in Pb Pb collisions does not increase any more with E T above 100 GeV.

1 data table
Table 1

ET - neutral transverse energy in the electromagnetic calorimeter, etarap=1.1-2.3.


The dependence of the anomalous J/psi suppression on the number of participant nucleons.

The NA50 collaboration Abreu, M.C ; Alessandro, B ; Alexa, C ; et al.
Phys.Lett.B 521 (2001) 195-203, 2001.
Inspire Record 564953 DOI 10.17182/hepdata.57435

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.

6 data tables
Table 1

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.

Table 2

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).;.

Table 3

SIG(J/PSI)/SIG(DY) as a function of E(C=ZDC) with the standard analyses of the 1996 DATA 1996, standard analyses.

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Evidence for deconfinement of quarks and gluons from the J/psi suppression pattern measured in Pb Pb collisions at the CERN-SPS.

The NA50 collaboration Abreu, M.C. ; Alessandro, B. ; Alexa, C. ; et al.
Phys.Lett.B 477 (2000) 28-36, 2000.
Inspire Record 524685 DOI 10.17182/hepdata.57430

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.

3 data tables
Table 1

SIG(J/PSI)/SIG(DY) as a function of ET with the standard analyses of 1996. DATA 1996, standard analyses.

Table 2

SIG(J/PSI)/SIG(DY) as a function of ET with the minium bias analyses of 1996. DATA 1996, MB Analyses.

Table 3

SIG(J/PSI)/SIG(DY) as a function of E(NAME=TRANSVERSE) with the minium bias analyses of 1998. DATA 1998, MB Analyses.


J / psi and Drell-Yan cross-sections in Pb Pb interactions at 158 GeV/c per nucleon

The NA50 collaboration Abreu, M.C. ; Alessandro, B. ; Alexa, C. ; et al.
Phys.Lett.B 410 (1997) 327-336, 1997.
Inspire Record 459315 DOI 10.17182/hepdata.5631

First results are reported on J ψ and Drell-Yan cross-sections in PbPb reactions at 158 GeV/ c per nucleon. The ratio of cross-sections σ J/ψ /σ DY is studied as a function of the impact parameter of the collision estimated from the measured transverse energy.

5 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

The Drell-Yan cross sections are taken in the mass interval 2.9 to 4.5 GeV. SIG/SIG ratio are free from most systematic errors.

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Anomalous J / psi suppression in Pb - Pb interactions at 158 GeV/c per nucleon

The NA50 collaboration Abreu, M.C. ; Alessandro, B. ; Alexa, C. ; et al.
Phys.Lett.B 410 (1997) 337-343, 1997.
Inspire Record 459314 DOI 10.17182/hepdata.28260

The Drell-Yan and J ψ cross-sections measured in PbPb collisions are compared with the values extrapolated from the results obtained in proton and light ion induced reactions. While the Drell-Yan production exhibits the normal expected behaviour, the yield of J ψ in PbPb interactions is abnormally low, as it lies 9 standard deviations below the expected value. Moreover, the departure from the expected behaviour increases significantly from peripheral to central collisions.

2 data tables
Table 1

The results from other experiments are also presented.

Table 2

Different data are rescaled at 200 GeV.


A measurement of R(b) using a double tagging method.

The OPAL collaboration Abbiendi, G. ; Ackerstaff, K. ; Alexander, G. ; et al.
Eur.Phys.J.C 8 (1999) 217-239, 1999.
Inspire Record 476786 DOI 10.17182/hepdata.49348

The fraction of Z to bbbar events in hadronic Z decays has been measured by the OPAL experiment using the data collected at LEP between 1992 and 1995. The Z to bbbar decays were tagged using displaced secondary vertices, and high momentum electrons and muons. Systematic uncertainties were reduced by measuring the b-tagging efficiency using a double tagging technique. Efficiency correlations between opposite hemispheres of an event are small, and are well understood through comparisons between real and simulated data samples. A value of Rb = 0.2178 +- 0.0011 +- 0.0013 was obtained, where the first error is statistical and the second systematic. The uncertainty on Rc, the fraction of Z to ccbar events in hadronic Z decays, is not included in the errors. The dependence on Rc is Delta(Rb)/Rb = -0.056*Delta(Rc)/Rc where Delta(Rc) is the deviation of Rc from the value 0.172 predicted by the Standard Model. The result for Rb agrees with the value of 0.2155 +- 0.0003 predicted by the Standard Model.

1 data table
Table 1

Second systematic error depends on Rc=Delta(R_c)/R_c ratio, where Delta(R_c) is the deviation of R_c from the value 0.172 predicted by the Standard Model.