Search for strange quark matter produced in relativistic heavy ion collisions

The E864 collaboration Armstrong, T.A. ; Barish, K.N. ; Batsouli, S. ; et al.
Phys.Rev.C 63 (2001) 054903, 2001.
Inspire Record 535783 DOI 10.17182/hepdata.31785

We present the final results from Experiment 864 of a search for charged and neutral strange quark matter produced in interactions of 11.5 GeV/c per nucleon Au beams with Pt or Pb targets. Searches were made for strange quark matter with A>4. Approximately 30 billion 10% most central collisions were sampled and no strangelet states with A<100 were observed. We find 90% confidence level upper limits of approximately 10^{-8} per central collision for both charged and neutral strangelets. These limits are for strangelets with proper lifetimes greater than 50 ns. Also limits for H^{0}-d and pineut production are given. The above limits are compared with the predictions of various models. The yields of light nuclei from coalescence are measured and a penalty factor for the addition of one nucleon to the coalescing nucleus is determined. This is useful in gauging the significance of our upper limits and also in planning future searches for strange quark matter.

9 data tables

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Measurements of total reaction cross-sections for some light nuclei at intermediate-energies

Fang, D.Q. ; Shen, W.Q. ; Feng, J. ; et al.
Phys.Rev.C 61 (2000) 064311, 2000.
Inspire Record 527655 DOI 10.17182/hepdata.25562

Measurements of the total reaction cross section for 12−16C, 14−17N, and 16−18O on carbon target at intermediate energies were performed on the Radioactive Ion Beam Line of the Heavy Ion Research Facility in Lanzhou. A larger enhancement of σR for 15C was observed than for its neighbors. Evidence for possible anomalous nuclear structure in 15C was revealed in the analysis of the total reaction cross section in terms of the difference factor d.

1 data table

No description provided.


Fragmentation studies of 158-A-GeV Pb ions using CR39 nuclear track detectors.

Dekhissi, H. ; Giacomelli, G. ; Giorgini, M. ; et al.
Nucl.Phys.A 662 (2000) 207-216, 2000.
Inspire Record 486410 DOI 10.17182/hepdata.43834

Six stacks of CR39 [(C 12 H 18 O 7 ) n , a Registered Trade Mark of PPG Industries, Inc.] nuclear track detectors with different targets were exposed to a lead ion beam of 158 A GeV at the CERN-SPS, at normal incidence, in order to study the fragmentation properties of ultra-relativistic lead nuclei. Measurements of the total, break-up and pick-up charge-changing cross sections of 158 A GeV Pb ions have been made for the first time.

5 data tables

Total charge-changing cross section.

Total charge-changing cross section.

Total charge-changing cross section.

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Total reaction and 2n-removal cross-sections of 20-60 A MeV He-4, He-6, He-8, Li-(6-9), Li-11, and Be-10 on Si

Warner, R.E. ; Patty, R.A. ; Voyles, P.M. ; et al.
Phys.Rev.C 54 (1996) 1700-1709, 1996.
Inspire Record 433951 DOI 10.17182/hepdata.25830

Total reaction cross sections, σR, of 20–60A MeV He4,6,8, Li6–9,11, and Be10 were measured by injecting magnetically separated, focused, monoenergetic, identified secondary beams of those projectiles into a Si detector telescope and measuring their energy-deposition spectra. These σR’s, accurate to about 3%, were compared with predictions of optical, strong absorption, and microscopic models. The latter gave the best overall fit to the data, providing long-tailed matter densities were assumed. The best available optical potentials generally overpredicted the data by about 10%. Strong absorption calculations, in which the isospin-dependent term is quite important, were often unsuccessful, especially for projectiles with large neutron excess. Two-neutron removal cross sections were measured for He6 and Li11; the Li11 data were slightly overpredicted by a microscopic model which includes correlation effects for the Li11 valence neutrons. Both 2n and 4n removal from He8 were observed, in about a 2:1 ratio. Subtraction analysis of the data indicates that He4 is a good core within He6 and He8, as is Li9 within Li11. © 1996 The American Physical Society.

9 data tables

Axis error includes +- 3/3 contribution (Statistical uncertainty is negligible).

Axis error includes +- 3/3 contribution (Statistical uncertainty is negligible).

Axis error includes +- 3/3 contribution (Statistical uncertainty is negligible).

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Global transverse energy distributions in Si + Al, Au at 14.6-A/GeV/c and Au + Au at 11.6-A.GeV/c

The E-802 collaboration Ahle, L. ; Akiba, Y. ; Beavis, D. ; et al.
Phys.Lett.B 332 (1994) 258-264, 1994.
Inspire Record 374156 DOI 10.17182/hepdata.28663

Measurements of the global transverse energy distributions dσ / dE T and dE T / dη using the new AGS beam of 197 Au at 11.6 A GeV/ c on a Au target, as well as a beam of 28 Si at 14.6 A GeV/ c on Al and Au targets, are presented for a leadglass detector with acceptance 1.3 ≤ η ≤ 2.4 and 0 ≤ φ < 2 π . The dσ / dE T spectra are observed to have different shapes for the different systems and simple energy rescaling does not account for the projectile dependence. The Au+Au dσ / dE T spectrum is satisfactorily constructed from the upper edge of Si+Au by the geometric Wounded Projectile Nucleon Model after applying a correction for the beam energy.

6 data tables

Incident energy is 14.6 GeV/nucleon.

Incident energy is 14.6 GeV/nucleon.

Incident energy is 11.6 GeV/nucleon.

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Production of helium fragments in Au-197 emulsion collisions at 10.6-A/GeV

Singh, G. ; Jain, P.L. ;
Z.Phys.A 348 (1994) 99-104, 1994.
Inspire Record 380467 DOI 10.17182/hepdata.16555

We present a systematic analysis on the helium projectile fragments produced from 10.6 A GeV197Auemulsion interactions in an experiment conducted at the Brookhaven AGS. Total charge changing and partial production cross-sections are measured experimentally on the basis of helium multiplicity. The multiplicity distribution of helium fragments which are produced collectively obey a KNO scaling. The transverse momentum distribution of these particles indicates that they are produced from two different independent sources.

3 data tables

THE TOTAL CHARGE CHANGING CROSS-SECTION WAS DETERMINED FROM THE INTERACTION MEAN FREE PATH OF NUCLEAR INTERACTIONS IN CONJUNCTION WITH THE DENSITY OF ATOMS IN EMULSION.

No description provided.

A SAMPLE OF SEMICENTRAL EVENTS SUCH THAT THE PROJECTILE FRAGMENTS OF CHARGES 2<=Z<=17 WERE SURVIVED IN AN INTERACTION.


Nuclear and electromagnetic fragmentation of 2.25-TeV Au-197 nuclei

He, Y.D. ; Price, P.B. ;
Z.Phys.A 348 (1994) 105-109, 1994.
Inspire Record 380468 DOI 10.17182/hepdata.16562

We report the first measurement of the total charge-loss cross section σtot=σem+σnuc and partial cross sections (for ΔZ=1, 2, ..., 9) of 11.4 A GeV197Au nuclei in various targets. The large Coulomb barrier for Au reduces the electromagnetic contribution σem in a Pb target to only 18% of σnuc, compared with ∼ 70% for 14.5 A GeV28Si and 120% for 200 A GeV32S. With σem taken to be ∝ZT1.8, σnuc can be fitted with σnuc=α(AP1/3 +AT1/3−b)2, with b=0.83 and α=59 mb, essentially the same as found at energies of 1 to 2 A GeV. Electromagnetic partial cross sections for ΔZ=1 exceed ∼ 40 mb in the Pb, Sn, Cu, and Fe targets and are substantial for larger values ofΔZ in the heavier targets.

2 data tables

TOTAL CHARGE-LOSS CROSS SECTION.

PARTIAL CHARGE-CHANGING CROSS SECTION.


Total and 2n removal cross-sections of the neutron rich isotopes Li-8, Li-9, Li-11

Blank, B. ; Gaimard, J.J. ; Geissel, H. ; et al.
Nucl.Phys.A 555 (1993) 408-434, 1993.
Inspire Record 335318 DOI 10.17182/hepdata.36666

Total interaction cross sections have been measured for 8 Li on C and Pb targets, for 9 Li on C, Al, Cu, Sn and Pb targets, as well as for 11 Li on C, Sn and Pb targets at about 80 MeV/nucleon. In addition, 2n-removal cross sections for 11 Li have been extracted. These measurements are used to determine the nuclear and the electromagnetic part of the cross sections for the different projectile-target combinations. The experimental results are compared to different model calculations. These comparisons allow one to draw conclusions on the matter density distribution of the neutron-rich lithium isotope 11 Li. By comparing our data on the electromagnetic dissociation of 11 Li with all the other data available in the literature, we are able to put constraints on the dipole-strength distribution in 11 Li.

1 data table

Axis error includes +- 0.0/0.0 contribution (?////).


Characteristics of helium fragments produced in Si-28 emulsion interactions at 14.5-A-GeV

Singh, G. ; Ismail, A.Z.M. ; Jain, P.L. ;
Phys.Rev.C 43 (1991) 2417-2421, 1991.
Inspire Record 323101 DOI 10.17182/hepdata.26112

We report the measurements on partial production cross sections of the multiple helium fragments emitted in the interactions of Si28 ions at 14.5A GeV in nuclear emulsion. Interaction mean free paths of the helium fragments have been investigated on the basis of helium multiplicity and size of the target nucleus as a function of the distance from their production points. Multiplicity scaling in the produced helium fragments is also observed.

5 data tables

FIRST REACTION RESPECTS CENTRAL, SECOND - PERIPHERAL INELASTIC INTERACTION.

FIRST REACTION RESPECTS CENTRAL, SECOND - PERIPHERAL INTERACTION. THIRD REACTION RESPECT 0HE PRODUCTION.

MULT(FRAGT) IS AVERAGED NUMBER OF HEAVY TRACKS FROM THE TARGET NUCLEUS, MULT(SHOWER) IS AVERAGED NUMBER OF MINIMUM IONIZING SHOWER TRACKS WHICH INCLUDED THE NUMBER OF SINGLY CHARGED PROJECTILE PROTON TRACKS.

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Measurement of the transverse energy flow in nucleus-nucleus collisions at 200-GeV per nucleon

The HELIOS collaboration Åkesson, T. ; Almehed, S. ; Angelis, A.L.S. ; et al.
Nucl.Phys.B 353 (1991) 1-19, 1991.
Inspire Record 299861 DOI 10.17182/hepdata.33034

The transverse energy distributions have been measured for interactions of 32 S nuclei with Al, Ag, W, Pt, Pb, and U targets, at an incident energy of 200 GeV per nucleon in the pseudorapidity region −0.1 < ν lab < 5.5. These distributions are compared with those for 16 OW interactions in the same pseudorapidity region and with earlier measurements performed with 16 O and 32 S projectiles in the region −0.1 < ν lab < 2.9. These comparisons provide both a better understanding of the dynamics involved and improved estimates of stopping power and energy density.

7 data tables

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