HEPData Search

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Collective expansion in high energy heavy ion collisions.

The NA44 collaboration Bearden, I.G. ; Boggild, H. ; Boissevain, J. ; et al.

Phys.Rev.Lett. 78 (1997) 2080-2083, 1997.

Inspire Record 426801 DOI 10.17182/hepdata.52345

Transverse mass spectra of pions, kaons, and protons from the symmetric heavy-ion collisions 200 A GeV S+S and 158 A GeV Pb+Pb, measured in the NA44 focusing spectrometer at CERN, are presented. The mass dependence of the slope parameters provides evidence of collective transverse flow from expansion of the system in heavy-ion induced central collisions.

3 data tables

Table 1

(1/MT)*d(N)/d(MT) = A *exp(-MT/SLOPE).

Table 2

(1/MT)*d(N)/d(MT) = A *exp(-MT/SLOPE).

Table 3

The SLOPE from the parameterization of (1/MT)*d(N)/d(MT) = A*exp(-MT/SLOPE)is fitted as follows SLOPE = CONST(C=1) + M(hadron)*CONST(C=2)**2.

Hadron yields and hadron spectra from the NA49 experiment

The NA49 collaboration Jones, P.G. ; Afanasiev, S.V. ; Alber, T. ; et al.

Nucl.Phys.A 610 (1996) 188C-199C, 1996.

Inspire Record 432742 DOI 10.17182/hepdata.36468

Preliminary inclusive spectra of negative hadrons, net protons and neutral strange particles are presented, measured by the NA49 experiment in central Pb+Pb collisions at 158 GeV per nucleon. Comparison of their yields with those from the lighter S+S system suggests that the yields scale approximately with the number of participating nucleons.

4 data tables

Table 1

CENTRAL COLLISIONS, PRELIMINARY DATA.

Table 2

CENTRAL COLLISIONS, PRELIMINARY DATA.

Table 3

CENTRAL COLLISIONS, PRELIMINARY DATA.

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Hadron distributions: Recent results from the CERN experiment NA44

The NA44 collaboration Xu, Nu ; Bearden, I.G. ; Bøggild, H. ; et al.

Nucl.Phys.A 610 (1996) 175C-187C, 1996.

Inspire Record 432743 DOI 10.17182/hepdata.36469

Proton distributions at midrapidity have been measured for 158A·GeV Pb+Pb collisions in the focusing spectrometer experiment NA44 at CERN. A high degree of nuclear stopping is found in the truly heavy ion collisions. Systematic results of single particle transverse momentum distributions of pions, kaons, and protons, of 200A·GeV S+S and 158A·GeV Pb+Pb central collisions will be addressed within the context of thermalization. By comparing these data with thermal and transport models, freeze-out parameters such as the temperature parameter T fo and mean collective flow velocity 〈β〉 are extracted. Preliminary results of the particle ratios of K − K + and p p are discussed in the context of cascade models of RQMD and VENUS.

1 data table

Table 1

CENTRAL COLLISIONS: SIG(TRIG)/SIG(GEOM)=10%.

Charged hadron distributions in p A and A-A collisions at the CERN SPS

The NA44 collaboration Dodd, Jeremy ; Bøggild, H. ; Boissevain, J. ; et al.

Nucl.Phys.A 590 (1995) 523C-526C, 1995.

Inspire Record 407678 DOI 10.17182/hepdata.36504

Single particle distributions of π ± , K ± , p , p and d near mid-rapidity from 450 GeV/c p A and 200 GeV/c per nucleon SA collisions are presented. Inverse slope parameters are extracted from the transverse mass spectra, and examined for indications of collective phenomena. Proton and antiproton yields are determined for different projectile-target combinations. First results from 160 GeV/c per nucleon PbPb collisions are presented.

2 data tables

Table 1

No description provided.

Table 2

PRELIMINARY DATA FOR CENTRAL EVENTS.

Recent results from NA44 and a review of HBT

The NA44 collaboration Jacak, B.V. ; Boggild, H. ; Boissevain, J. ; et al.

Nucl.Phys.A 590 (1995) 215C-232C, 1995.

Inspire Record 407654 DOI 10.17182/hepdata.36517

None

1 data table

Table 1

PRELIMINARY DATA FOR CENTRAL EVENTS.

Observation of enhanced subthreshold K+ production in central collisions between heavy nuclei

Miskowiec, D. ; Ahner, W. ; Barth, R. ; et al.

Phys.Rev.Lett. 72 (1994) 3650-3653, 1994.

Inspire Record 373335 DOI 10.17182/hepdata.19695

In the very heavy collision system Au197+197Au the K+ production process was studied as a function of impact parameter at 1 GeV/nucleon, a beam energy well below the free N-N threshold. The K+ multiplicity increases more than linearly with the number of participant nucleons and the K+/π+ ratio rises significantly when going from peripheral to central collisions. The measured K+ double differential cross section is enhanced by a factor of 6 compared to microscopic transport calculations if secondary processes (ΔN→KΛN and ΔΔ→KΛN) are ignored.

2 data tables

Table 1

No description provided.

Table 2

The total K+ cross section is determined by extrapolating and integrating the double differential cross section d2(sig)/d(p)/d(omega) over momentum and solid angle.

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.

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Rapidity and transverse momentum distributions in 6.4-TeV S + Pb interactions from CERN EMU05 experiments. EMU-005 experiment

Iyono, A. ; Takahashi, Y. ; Gregory, J.C. ; et al.

Nucl.Phys.A 544 (1992) 455C-458C, 1992.

Inspire Record 343252 DOI 10.17182/hepdata.36672

Mixed transverse(P T ) momentum and rapidity distributions of charged particles produced in 200 GeV/AMU heavy ion collisions are obtained with Magnetic-Interferometric-Emulsion-Chamber ( MAGIC ) by CERN-EMU05 experiments. The P T spectra at different rapidity regions showed no anomalous enhancement of low P T components over a conventional, single exponential function with slope values ranging from 160 to 200 MeV/c.

1 data table

Table 1

EVENTS SELECTED FOR THE ANALYSIS ARE THOSE WITH CHARGED MULTIPLICITY MORE THAN 400 FOR CENTRAL S+PB COLLISIONS.

Meson production in p + U, O + U and S + U interactions at 200-GeV/nucleon.

The NA38 collaboration Abreu, M.C. ; Baglin, C. ; Baldisseri, A. ; et al.

Z.Phys.C 55 (1992) 365-371, 1992.

Inspire Record 344266 DOI 10.17182/hepdata.14583

Meson production in proton, oxygen and sulphur interactions with uranium targets at 200 GeV/nucleon is studied. We measure the inclusive meson cross-section d σ/dPT2 and its evolution fromp+U to S+U. The cross-section fitted with an exponential gives an inverse slopePT0 of the order of 210 MeV/c. As a function of the neutral transverse energy,PT0 values show a slight rise followed by a plateau. The normalized difference (σ+−σ−)/σ− between positive and negative meson cross-sections is found to increase withET.

6 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.