123349552
Data implying formation of a moving source in collisions of carbon-12 nuclei with various target nuclei at 3.6 GeV/nucleon
Abstract Inclusive spectra of protons emitted in the interaction of 12 C-projectiles at an energy of 3.6 GeV/nucleon and C, Cu, Sn and Pb target nuclei were measured. The analysis of the experimental data suggests that in all these interactions the main contribution to proton cross sections in the investigated kinematic region is due to emission from a moving source with a rapidity which differs greatly from the target nucleus rapidity, y t , as well as from that of the effective fireball. The properties of this source such as the excitation energy depend only slightly on the combination of the colliding nuclei.
109550892
A new VME-based high voltage power supply for large photomultiplier systems
Abstract We describe a new high voltage power supply, developed for the leadglass calorimeter of the WA98 experiment at CERN. The high voltage is produced for each of the 10 080 photomultiplier tubes of the detector individually, by the same number of active bases with on-board Greinacher voltage multipliers. The full VME-based HV controller system, which addresses each base via bus cables once per second, is miniaturized and fits into a single VME crate. The main advantages of this approach are the low heat dissipation, the considerably reduced amount of cabling and cost, as well as the high stability and low noise of the system.
126031532
EMISSION OF COMPOUND LIGHT FRAGMENTS IN COLLISIONS BETWEEN RELATIVISTIC NUCLEI. (IN RUSSIAN)
104363365
MEASUREMENT OF THE SPECTRA OF DOUBLY CHARGED PARTICLES EMITTED BY LEAD NUCLEI BOMBARDED BY 3.6-GEV/NUCLEON PARTICLES. (IN RUSSIAN)
125898346
Photons and neutral mesons from hot hadronic matter
Results from the experimental program with light ion beams and heavy target nuclei at the CERN SPS could demonstrate the occurrence of an unprecedented state of high density in hadronic matter. The thermal nature of the hadronic system has been investigated by analyzing spectra and production ratios of hadrons which reveal a large degree of rescattering of primary and secondary hadrons.Thermal photons from elementary quark-gluon interactions are considered a promising signal for the occurrence of a phase transition to the quark-gluon plasma. The predictions for thermal photons from elementary parton interactions are discussed and compared to the thermal emission rate of photons from a hot hadronic gas. Recent results from the photon spectrometers in heavy ion experiments are presented. Production cross sections of pi0 and eta mesons are determined and the projectile and target mass dependence is discussed. An upper limit for the single photon yield was determined for central O+Au reactions. Recent S+Au reactions exhibit an excess of photons over the yield expected from hadronic decays. The spectral shape of the expected single photon signal is discussed which might reveal the temperature of hot matter and indicate a phase transition.
122152880
Large-angle two-particle correlations in nucleus-nucleus collisions at 3.6 GEV/nucl.
Abstract For nucleus-nucleus collisions at 3.6 GeV/nucl., we have measured correlations between a charged particle emitted in the range from 10° to 18° and identified a charged fragment (proton, deutron or pion) emitted at a certain angle in the range of 45°–130°. The following projectile-target combinations were studied: C+Al (45°, 60°, 80°, 130°); C+Cu (45°, 60°, 80°); C+Pb (45°, 60°, 80°, 130°); He+Al (45°, 80°, 130°); He+Pb (45°, 80°, 130°). In all the studied reactions, correlated particle emission has been observed.
7992539
Vacuum Einstein metrics with bidimensional Killing leaves ∗ I-Local aspects.
Abstract The solutions of vacuum Einstein's field equations, for the class of Riemannian metrics admitting a non-Abelian bidimensional Lie algebra of Killing fields, are explicitly described. They are parametrized either by solutions of a transcendental equation (the tortoise equation ), or by solutions of a linear second order differential equation in two independent variables. Metrics, corresponding to solutions of the tortoise equation, are characterized as those that admit a 3-dimensional Lie algebra of Killing fields with bidimensional leaves.
116200939
Self-Stimulated Undulator Radiation and its Possible Applications
We investigated the phenomena of self-stimulation of incoherent emission from an undulator installed in the linear accelerator or quasi-isochronous storage ring. We discuss possible applications of these phenomena for the beam physics also.