Measurements have been made of inclusive 525 GeV π− interactions in emulsion. The results are compared to proton-emulsion and lower energy pion-emulsion data. Average multiplicities of relativistic shower particles increase with increasing energy, although with a somewhat steeper slope above 60 GeV than at lower energies. The ratio 〈ns〉p/〈ns〉π∼1.1 over the energy range 60–525 GeV. The ratio of the dispersion in the multiplicity distribution to the average multiplicity is the same for proton and pion collisions in emulsion, and is independent of projectile energy. The shape of the shower particle multiplicity distribution does not vary significantly with energy, and KNO scaling appears to hold over the energy range 60–525 GeV. The shower particle pseudorapidity distributions are independent of the beam energy in the target and projectile fragmentation regions, and both the pseudorapidity and multiplicity distributions agree reasonably well with the fritiof model predictions for 525 GeV pions. The dependence of the shower particle multiplicity 〈ns〉 on the number of heavy tracks Nh appraoches saturation as the total shower particle energy becomes a significant fraction of √s , and the pseudorapidity distributions shift toward smaller 〈η〉 with increasing numbers of grey and black tracks at 525 GeV. Neither the average number 〈Nh〉 nor the multiplicity distributions of the heavily ionizing tracks vary significantly with energy, and the normalized angular distributions of grey and black tracks are independent of the type of projectile or projectile energy.
NUCLEUS means average nuclei of BR-2 emulsion.
NUCLEUS means average nuclei of BR-2 emulsion.
NUCLEUS means average nuclei of BR-2 emulsion.
We report a new measurement of the differential cross section for π−p→π0n from pπ=649 to 752 MeV/c, which is around the opening of the η channel (685 MeV/c). Our data support the main features of the π−p charge-exchange differential cross sections generated by the SAID πN partial-wave analysis. The opening of the η channel has a clear effect on the shape of the excitation function for dσ(π−p→π0n), which is most noticeable in the backward direction.
Differential cross section for incident pion momentum 649, 654 and 657 MeV.
Differential cross section for incident pion momentum 661, 666 and 669 MeV.
Differential cross section for incident pion momentum 673, 678 and 681 MeV.
We report a new measurement of the π−p→3π0n total cross section from threshold to pπ=0.75GeV/c. The cross section near the N(1535)12− resonance is only a few μb after subtracting the large η→3π0 background associated with π−p→ηn. A simple analysis of our data results in the estimated branching fraction B[S11→πN(1440)12+]=(8±2)%. This is the first such estimate obtained with a three-pion production reaction.
Total cross section from threshold to 750 MeV. Only statistical errors are given in the table.
We present data on the production of the baryons Λ,\(\bar \Lambda \),p and of the baryon resonances Σ*+ (1385) and Δ++ (1232) inK+p and π+p interactions at 250 GeV/c. Results are given on total and semi-inclusive cross sections, Feynman-x spectra, transverse momentum distributions and Λ polarization. The data are compared with measurements at lower energies, with deep inclastic lepton nucleon data and with predictions of quark-parton models. The models underestimate Λ production in the central c.m. region, a feature also seen in recent heavy-ion data. This failure can be cured in JETSET 6.3 by adjustment of the di-quark break-up probability.
No description provided.
No description provided.
No description provided.
None
No description provided.
The fragmentation topology of28Si at 3.7A GeV and 14.6A GeV and32S at 200A GeV in reactions with emulsion nuclei is presented. The fragmentation cross sections are very similar at all three energies. A statistical percolation model can qualitatively describe the data forZ≥ 6. The He production is underestimated and the 3 ≤Z ≤ 5 fragments overestimated by this model.
JINR.
BNL-815.
CERN-EMU-001.
Pseudorapidity distributions of relativistic singly charged particles in oxygen-induced emulsion interactions at 14.6, 60, and 200 GeV/nucleon are studied. Limiting fragmentation behavior is observed in both the target and projectile fragmentation regions for a central as well as for a minimum-bias sample. Comparisons with the fritiof model reveal that the picture of fragmenting strings successfully describes the observed data.
NUCLEUS IS AVERAGE NUCLEUS OF EMULSION.
NUCLEUS IS AVERAGE NUCLEUS OF EMULSION.
The energy and centrality dependence of local particle pseudorapidity densities as well as validity of various parametrizations of the distributions are examined. The dispersion, σ, of the rapidity density distribution of produced particles varies slowly with centrality and is 0.80, 0.98, 1.21 and 1.41 for central interactions at 3.7, 14.6, 60 and 200A GeV incident energy, respectively, σ is found to be independent of the size of the interacting system at fixed energy. A novel way of representing the window dependence of the multiplicity as normalized variance versus inverse average multiplicity is outlined.
No description provided.
NUCLEUS IS AGBR, CENTRAL EVENTS.
No description provided.
We report the results of a study of the reaction p p → p + x at 32.1 GeV c , where the recoiling proton has a small laboratory momentum. The reaction is studied in the 4.5 m Mirabelle bubble chamber at Serpukhov. We compare the diffractive dissociation of the incident antiproton to other incident particles.
No description provided.
CALCULATED USING THE OPTICAL THEOREM AND THE TOTAL CROSS SECTION FOR AP P OF 46 +- 0.3 MB.
TOPOLOGICAL AND BEAM DIFFRACTION CROSS SECTIONS WITH PLAB(FINAL STATE PROTON) < 1.1 GEV/C.
None
THE MOMENTUM OF EACH INCIDENT PION WAS DETERMINED WITH AN ACCURACY 0.2 PCT.
THE MOMENTUM OF EACH INCIDENT PION WAS DETERMINED WITH AN ACCURACY 0.2 PCT.
THE MOMENTUM OF EACH INCIDENT PION WAS DETERMINED WITH AN ACCURACY 0.2 PCT.
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