The results of a search for narrow resonances ine+e− annihilation at centre-of-mass energies between 7.23 and 10.34 GeV are presented. The experiment was performed using the MD-1 detector at the VEPP-4 storage ring. The total luminosity integral of 16 pb−1 was taken. There is no evidence that new states exist. The upper limits on the leptonic widthΓee of possible resonances are less, by a factor of 10–80, than theΓee for the ϒ(1S) meson.
Average R value (excluding upsilon region).
The absolute p-d elastic-scattering differential cross sections were measured at 641.3 and 792.7 MeV beam energies over a range of c.m. angles from ∼35° to ∼115° and ∼35° to ∼140°, respectively. The longitudinally polarized (L-type) proton beam produced by the Lamb-shift ion source at LAMPF was used. The beam intensity was measured to high accuracy (∼0.1%) by a scintillator-beam particle-counting system designed and developed prior to the experiment. Typical uncertainties in the absolute cross sections were about 2–3% total, somewhat larger at back angles. The present results were compared with the existing measurements and the controversy about the previous data at 800 MeV was resolved. The present data can be fit with a relativistic multiple-scattering theory which uses off-mass-shell extrapolations of the nucleon-nucleon amplitudes suggested by the structure of derivative meson-nucleon couplings. Relativistic-impulse-approximation calculations do not fit these data at either energy.
TARGET IS A LIQUID DEUTERIUM. THE LABORATORY ANGLES BIN SIZES ARE 30 MRAD AT FORWARD ANGLES AND 50 MRAD AT OTHER ANGLES.
TARGET IS A LIQUID DEUTERIUM. THE DATA IN THIS TABLE ARE THE SAME AS IN THE TABLE 1, BUT IN THE ANOTHER REPRESENTATION.
TARGET IS A LIQUID DEUTERIUM. THE DATA IN THIS TABLE ARE THE SAME AS IN THE TABLE 1, BUT IN THE ANOTHER REPRESENTATION.
None
No description provided.
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.
Spectra, angular distributions, and integrated cross sections for inclusive inelastic scattering of 96.5-MeV π+ and π− from H2, He3, and He4 are presented. The measurements were made using a high-pressure gas cell, which permits an accurate determination of relative cross sections for all targets. The data are compared with distorted-wave impulse-approximation calculations and with a modified plane-wave impulse-approximation calculation. In addition, by combining the total inelastic cross sections from this work with estimates of single-charge-exchange cross sections and with published values and reasonable estimates of the other π+ cross sections at the same energy, values for total reaction and pion absorption cross sections are obtained for all the targets. The dependence of these cross sections on Z, N, nuclear density, and nuclear binding energy is discussed in terms of a simple model.
No description provided.
No description provided.
Absolute π±d differential cross sections and charge asymmetries have been measured at an incident pion energy of 65 MeV, using an active target of deuterated scintillator plastic to detect recoil deuterons in coincidence with scattered pions. Statistical and systematic uncertainties in the cross sections are each typically ±3%. The charge asymmetry is consistent with theoretical predictions.
No description provided.
An angular method of identifying diffractive excitation (DE) events for interactions of a hadron beam in nuclear emulsion is applied to identifying DE events in interactions of heavy ions beams. The ‘‘apparent’’ mean free paths (MFP) of DE processes for O16 (28Si) beams are 1.00±0.12, 2.4−0.7+1.6, and 2.2±0.4 (1.5±0.2) m, respectively, at 200, 60, and 14.6 GeV/nucleon, which corresponds to 20–10% of the MFP for total inelastic interactions. Distinctive features of diffractively excited nuclei are discussed.
No description provided.
No description provided.
No description provided.
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ABSENT OF AN ABSOLUTE NEUTRON FLUX NORMALIZATION DIDN'T ALLOWED TO DEFINE THE CROSS-SECTION OF LAMBDA-K0-PARE PRODUCTION,SO IT WAS DEFINED THE RELATION OF CARBON AND CUPRUM CROSS-SECTION.
Production of multi-strange baryons and antibaryons is expected to be a useful indicator in the search for Quark-Gluon Plasma formation. Production of Ξ − and Ξ − has been observed for the first time in ultra-relativistic heavy ion interactions by the WA85 Experiment. We describe the procedure used to select these cascade candidates and show that Ξ − and Ξ − decays can be identified. Preliminary ratios of Ξ/Ξ production in sulphur-tungsten and proton-tungsten interactions are also presented.
PRODUCTION AT CENTRAL RAPIDITY. 123 XI- AND 53 XIBAR+ CANDIDATES.
PRODUCTION AT CENTRAL RAPIDITY. 82 XI- AND 22 XIBAR+ CANDIDATES.
Dimuon production m p-U, O-U and S-U collisions has been studied at 200 GeV/N. It is observed that 〈 p T 〉 and 〈 p 2 T 〉 of the J / Ψ transverse momentum distributions increase with the transverse energy of the ion induced reactions. Such a marked behaviour is not seen for muon pairs of the continuum.
No description provided.
No description provided.
No description provided.
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