HEPData Search

Measurements of charged pion and kaon production in central Pb+Pb collisions at 40, 80 and 158 AGeV are presented. These are compared with data at lower and higher energies as well as with results from p+p interactions. The mean pion multiplicity per wounded nucleon increases approximately linearly with s_NN^1/4 with a change of slope starting in the region 15-40 AGeV. The change from pion suppression with respect to p+p interactions, as observed at low collision energies, to pion enhancement at high energies occurs at about 40 AGeV. A non-monotonic energy dependence of the ratio of K^+ to pi^+ yields is observed, with a maximum close to 40 AGeV and an indication of a nearly constant value at higher energies.The measured dependences may be related to an increase of the entropy production and a decrease of the strangeness to entropy ratio in central Pb+Pb collisions in the low SPS energy range, which is consistent with the hypothesis that a transient state of deconfined matter is created above these energies. Other interpretations of the data are also discussed.

33 data tables

Table 1

The centrality of the collisions expressed as a percentage of the inelastic cross section (7.15nb), and the mean numbers of wounded nuclei.

Table 2

The inverse slope parameter of the fitted transverse mass spectra.

Table 3

The rapidity density averaged over the rapidity interval -0.6 to 0.6.

More…

Charged particle production in S S collisions at 200-GeV/c per nucleon

The WA94 collaboration Andrighetto, A. ; Antinori, F. ; Bayes, A.C. ; et al.

Phys.Lett.B 412 (1997) 148-154, 1997.

Inspire Record 460283 DOI 10.17182/hepdata.28242

Charged particle production in central S-S collisions at 200 GeV/ c per nucleon has been studied by the WA94 experiment at the CERN-SPS. Particle identification has been provided by the Omega RICH, while a silicon telescope in the Omega spectrometer and an array of MultiWire Proportional Chambers have been used to trace particles through the RICH detector. Production ratios and transverse mass spectra for π ± , K ± and p( p ) at central rapidity and p T > 1.3 GeV/ c are presented.

3 data tables

Table 1

Distributions are fitted with (1/MT**1.5)*DSIG/DMT = CONST*EXP(-MT/SLOPE).

Table 2

1.54 GeV ratio is calculated from the fit to the MT distribution.

Table 3

1.54 GeV ratio is calculated from the fit to the MT distribution.

CORRELATIONS OVER MULTIPLICITY BETWEEN NEGATIVE PIONS AND PROTONS: PARTICIPANTS IN C Ta INTERACTIONS AT 4.2-GeV/c PER NUCLEON MOMENTUM

Backovic, S. ; Boldea, V. ; Grishin, V.G. ; et al.

Sov.J.Nucl.Phys. 50 (1989) 1001-1005, 1989.

Inspire Record 269366 DOI 10.17182/hepdata.38833

None

5 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

Production of pi+-, K+-, p, and anti-p in relativistic Au + Pt, Si + Pt, and p + Pt collisions

The E886 collaboration Diebold, G.E. ; Bassalleck, B. ; Burger, T. ; et al.

Phys.Rev.C 48 (1993) 2984-2994, 1993.

Inspire Record 364483 DOI 10.17182/hepdata.26015

During the recent commissioning of Au beams at the Brookhaven Alternating Gradient Synchrotron facility, experiment 886 measured production cross sections for π±, K±, p, and p¯ in minimum bias Au+Pt collisions at 11.5A GeV/c. Invariant differential cross sections, Ed3σ/dp3, were measured at several rigidities (p/Z≤1.8 GeV/c) using a 5.7° (fixed-angle) focusing spectrometer. For comparison, particle production was measured in minimum bias Si+Pt collisions at 14.6A GeV/c using the same apparatus and in p+Pt collisions at 12.9 GeV/c using a similar spectrometer at KEK. When normalized to projectile mass, Aproj, the measured π± and K± cross sections are nearly equal for the p+Pt and Si+Pt reactions. In contrast to this behavior, the π− cross section measured in Au+Pt shows a significant excess beyond Aproj scaling of the p+Pt measurement. This enhancement suggests collective phenomena contribute significantly to π− production in the larger Au+Pt colliding system. For the Au+Pt reaction, the π+ and K+ yields also exceed Aproj scaling of p+Pt collisions. However, little significance can be attributed to these excesses due to larger experimental uncertainties for the positive rigidity Au beam measurements. For antiprotons, the Si+Pt and Au+Pt cross sections fall well below Aproj scaling of the p+Pt yields indicating a substantial fraction of the nuclear projectile is ineffective for p¯ production. Comparing with p+Pt multiplicities, the Si+Pt and Au+Pt antiproton yields agree with that expected solely from ‘‘first’’ nucleon-nucleon collisions (i.e., collisions between previously unstruck nucleons). In light of expected p¯ annihilation in the colliding system, such projectile independence is unexpected without additional (projectile dependent) sources of p¯ production. In this case, the data indicate an approximate balance exists between absorption and additional sources of antiprotons. This balance is remarkable given the wide range of projectile mass spanned by these measurements.

13 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

Multiplicity, Momentum and Angular Characteristics of $\pi^-$ Mesons for $p$ C, $d$ C, $\alpha$ C and C C Interactions at 4.2-{GeV}/$c$ Per Nucleon

The Alma Ata-Baku-Belgrade-Bucharest-Dubna-Kishinev-Leipzig- Moscow-Prague-Samarkand-Sofiya-Tashkent-Tbilisi-Ulan Bator-Varna collaboration Agakishiev, G.N. ; Akhababian, N. ; Armutliisky, D. ; et al.

Z.Phys.C 27 (1985) 177, 1984.

Inspire Record 203342 DOI 10.17182/hepdata.1999

Light ion collisions with carbon target at 4.2 GeV/c/N are studied. Pion multiplicity distributions, momentum and angular spectra are analysed. These data are described in terms of models assuming independent interactions of nucleons from the projectile nucleus with the target.

18 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.