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.
Incident energy is 14.6 GeV/nucleon.
Incident energy is 14.6 GeV/nucleon.
Incident energy is 11.6 GeV/nucleon.
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.
No description provided.
No description provided.
No description provided.
Transverse-energy distributions have been measured for the collisions of the 32 S nucleus with Al, Ag, W, Pt, Pb, and U target nuclei, at an incident energy of 200 GeV per nucleon. The shapes of these distribution reflect the geometry of the collisions, including the deformation effects. For central collisions, the transverse-energy production in the region −0.1< η lab <2.9 increases approximately as A 0.5 , where A is the atomic mass number of the target. This increase is accompanied by a relative depletion in the forward region η lab > 2.9. These results are compared with those obtained under similar conditions with incident 16 O nuclei. A comparison is also made with the predictions of a Monte Carlo generator based on the dual parton model. Finally, we give estimates of the energy density reached and its dependence on the atomic mass number of the projectile.
No description provided.
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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 OW 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.
No description provided.
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Cross sections for charge changing and particle production are measured for 32 S collisions with Al, Fe, Cu, Ag and Pb targets at 200 GeV/ c . The measured difference between the two cross sections is discussed. Results are compared with data obtained with an 16 O beam.
Charge changing cross section.
Production cross section.
Cross sections are measured for 16 O collisions with A1 and Pb. Dependences on beam momentum and atomic number are compared with data obtained at much lower beam momenta.
MODEL DEPENDENT ESTIMATION.
No description provided.
No description provided.
Interaction cross sections (σI) for all known Li isotopes (Li6-Li11) and Be7, Be9, and Be10 on targets Be, C, and Al have been measured at 790 MeV/nucleon. Root mean square radii of these isotopes as well as He isotopes have been deduced from the σI by a Glauber-type calculation. Appreciable differences of radii among isobars (He6-Li6, He8-Li8, and Li9-Be9) have been observed for the first time. The nucleus Li11 showed a remarkably large radius suggesting a large deformation or a long tail in the matter distribution.
No description provided.
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.
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).
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.
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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