HEPData Search

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Strangelet search and light nucleus production in relativistic Si + Pt and Au + Pt collisions

The E886 collaboration Rusek, A. ; Bassalleck, B. ; Berdoz, A. ; et al.

Phys.Rev.C 54 (1996) R15-R19, 1996.

Inspire Record 429741 DOI 10.17182/hepdata.25801

A strangelet search in Si+Pt and Au+Pt collisions at alternating-gradient synchrotron (AGS) energies, using a focusing spectrometer, sensitive to mass per charge of 3-14 GeV/c2 was conducted during the 1992 and 1993 heavy ion runs at the AGS. The null results thereof are presented as upper limits on the invariant production cross section, in the range of 10−5-10−4 mb c3/GeV2, and model dependent sensitivity limits in the range of 10−7-10−5 per collision. Measurements of the production cross sections of several nonstrange nuclear systems, from p to Be7 and Li8, the background of the strangelet search, are also presented.

1 data table

Table 1

No description provided.

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%.

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.

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.

Composite particle production in relativistic Au + Pt, Si + Pt, and p + Pt collisions

The E886 collaboration Saito, N. ; Bassalleck, B. ; Burger, T. ; et al.

Phys.Rev.C 49 (1994) 3211-3218, 1994.

Inspire Record 383739 DOI 10.17182/hepdata.25998

Recently, highly relativistic Au beams have become available at the Brookhaven National Laboratory, Alternating Gradient Synchrotron. Inclusive production cross sections for composite particles, d, t, He3, and He4, in 11.5A GeV/c Au+Pt collisions have been measured using a beam line spectrometer. For comparison, composite particle production was also measured in Si+Pt and p+Pt collisions at similar beam momenta per nucleon (14.6A GeV/c and 12.9 GeV/c, respectively). The projectile dependence of the production cross section for each composite particle has been fitted to Aprojα. The parameter α can be described by a single function of the mass number and the momentum per nucleon of the produced particle. Additionally, the data are well described by momentum-space coalescence. Comparisons with similar analysis of Bevalac A+A data are made. The coalescence radii extracted from momentum-space coalescence fits are used to determine reaction volumes (‘‘source size’’) within the context of the Sato-Yazaki model.

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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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Intranuclear cascade percolation approach for protons and light fragments production in neon niobium reactions at 400-MeV and 800-MeV per nucleon

Montarou, G. ; Marroncle, J. ; Alard, J.P. ; et al.

Phys.Rev.C 47 (1993) 2764-2781, 1993.

Inspire Record 362233 DOI 10.17182/hepdata.26046

The results of intranuclear cascade calculations (ideal gas with two-body collisions and no mean field), complemented by a simple percolation procedure, are compared with experimental data on protons and light nuclear fragments (d, t, He3, and He4) measured in 400 and 800 MeV/nucleon Ne+Nb collisions using a large solid angle detector. The model reproduces quite well global experimental observables like nuclear fragment multiplicity distributions or production cross sections, and nuclear fragment to proton ratios. For rapidity distributions the best agreement occurs for peripheral reactions. Transverse momentum analysis confirms once again that the cascade, although being a microscopic approach, gives too small a collective flow, the best agreement being reached for Z=2 nuclear fragments. Nevertheless these comparisons are encouraging for further improvements of the model. Moreover, such an approach is easy to extend to any other models that could calculate the nucleon phase space distribution after the compression stage of the reaction, when light nuclear fragments emitted at large angles are constructed from percolation.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Saturation of the thermal energy deposited in Au and Th nuclei by Ar projectiles between 27 and 77 MeV/u

Jiang, D.X. ; Doubre, H. ; Galin, J. ; et al.

Nucl.Phys.A 503 (1989) 560-574, 1989.

Inspire Record 25834 DOI 10.17182/hepdata.36893

Multiplicities of neutrons and light charged particles associated with central collisions have been measured in the energy range 27–77 MeV/u for the systems 40 Ar+ 197 Au, 232 Th. The experiments demonstrate the occurrence of a saturation of the thermal energy deposited in the system around 650 MeV, corresponding to a constant internal temperature close to 5 MeV.

6 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.