Ring-Like and Jet-Like Events in Ultra High-Energy Interactions—an Analysis in Terms of Multifractal Parameters
Ring-like and jet-like events produced in 16O-AgBr interactions at 60 AGeV are analyzed in terms of multifractal G-moment method and factorial moment method in both η space and ϕ space for emitted pions. Further, the Levy indices and multifractal specific heat c have been calculated. The results clearly indicate that μ and c both are different in ring-like and jet-like events depicting different mechanism in the production process.

title: MULTIPLICITY DISTRIBUTION AND MULTIPLICITY MOMENT OF BLACK AND GREY PARTICLES IN HIGH ENERGY NUCLEUS–NUCLEUS INTERACTIONS
abstract: In this paper we have studied the multiplicity distribution of black and grey particles emitted from 16O–AgBr interactions at 2.1 AGeV and 60 AGeV. We have also calculated the multiplicity moment up to the fifth order for both the interactions and for both kinds of emitted particles. The variation of multiplicity moment with the order number has been investigated. It is seen that in the case of black particles multiplicity moment up to fourth order remains almost constant as energy increases from 2.1 AGeV to 60 AGeV. Fifth order multiplicity moment increases insignificantly with energy. However in the case of grey particles no such constancy of multiplicity moment with energy of the projectile beam is obtained. Later we have extended our study on the basis of Regge–Mueller approach to find the existence of second order correlation during the emission of black as well as the grey particles. The second Mueller moment is found to be positive and it increases as energy increases in the case of black particles. On the contrary in the case of grey particles the second Mueller moment decreases with energy. It can be concluded that as energy increases correlation among the black particles increases. On the other hand with the increase of energy correlation among the grey particles is found to diminish.

title: Evidence of different reaction mechanisms for hot and cold events in relativistic heavy-ion interaction
abstract: This paper reports evidence of different reaction mechanisms for two classes of events, ''hot,'' and ''cold,'' in /sup 12/C emulsion at 4.5 (GeV/c)/N observed by Ghosh et al., from a comparison of the transverse-momentum (P/sub T/) distribution with a mixture of two Maxwell-Boltzmann distributions with different temperatures. The hypothesis is substantiated by the significant difference, for ''hot'' and ''cold'' events, in the values of the average number of pions produced, average emission angle of ..cap alpha..-projectile fragments, and ratio of yield of ..cap alpha.. particles to protons as projectile fragments.

title: NON-STATISTICAL FLUCTUATIONS OF PIONS FOR RING- AND JET-LIKE EVENTS AT CERN SPS ENERGY — AN IN-DEPTH ANALYSIS WITH FACTORIAL CORRELATOR
abstract: This study reveals the analysis of ring-like and jet-like events in terms of factorial correlations of 16O–Ag/Br interactions at 60A GeV. The investigation revealed that the correlated moments are found to increase with decreasing bin–bin separation D and follows a power-law which suggests the presence of an intermittent nature of self-similar dynamical fluctuations pattern for ring-like and jet-like events. From the analysis we find that for jet-like events the strength of non-statistical fluctuation is greater than the ring-like and total event set. Jet-like events follow the bin size independence according to α model of intermittency as like total events, whereas ring-like events are not consistent with the prediction of α model of intermittency.

title: Entropy scaling in high-energy nucleus–nucleus interactions
abstract: We studied the multiparticle production in high-energy nucleus–nucleus interactions in terms of particle entropy in 16O–AgBr and 32S–AgBr interactions at 60 A GeV and 200 A GeV, respectively. An approximate scaling behavior of total produced entropy normalized to maximum rapidity in the center of mass frame measured in different rapidity bins has been reported. The scaling behavior is not supported either by the FRITIOF model or by the Monte Carlo simulated events.

title: Multiplicity fluctuations of pions and protons at SPS energy — An in-depth analysis with factorial correlator
abstract: We compute the factorial correlators to study the dynamical fluctuations of pions and a combination of pions and protons (compound multiplicity) in 32S-AgBr interactions at 200 A GeV. The study reveals that for both pion and compound multiplicity the correlated moments increase with the decrease in bin-bin separation D, following a power-law, which suggests the self-similarity of multiplicity fluctuation in each case. The results of the analysis also show a consistency with the prediction of α-model for the existence of intermittency in both cases.

title: Observing CP violating MSSM Higgs bosons at hadron colliders
abstract: We report on the possibility of observing Higgs sector CP violation of the minimal supersymmetric standard model at a hadron machine. The CP phase dependent cross-sections for the VH i associated production processes are given for the Fermilab Tevatron and CERN LHC. Substantial production cross-sections for channels of all three Higgs bosons simultaneously are shown to be possible, giving a direct indication of the CP violation. The observability of the Higgs signals are discussed.

title: QCD analysis of polarized parton densities
abstract: We present the results of QCD fits to global data on deep-inelastic polarized lepton-hadron scattering. We find that it is possible to fit the data with strongly broken SU(2) flavor for the polarized sea densities. This can be tested in W production at the polarized BNL RHIC. The data fail to pin down polarized singlet sea quark and gluon densities. We explore the uncertainties in detail and show that improvement in statistics, achievable at the polarized DESY HERA for measurement of A 1 at moderately low values of x, have large payoffs in terms of the improvement in measurement of gluon densities.

title: Can the Aleph four-jet excess be explained in a supersymmetric model with R-parity violation?
abstract: We investigate the possibility that the excess of four-jet events in e+e− collisions at LEP-1.5 which has been reported by the ALEPH Collaboration could be due to the production of charginos or neutralinos, followed by their decay into quark jets through baryon number-violating (λ″) couplings. An estimate at the parton level shows, however, that these events cannot be due to neutralinos because of the low cross-section, and is unlikely to be due to the production of chargino pairs because of the largely different event shapes.

title: Combined squark and gluino mass bounds from LEP data
abstract: Under the assumption of gaugino mass unification at a high scale, chargino and neutralino masses depend on the value of the gluino mass, which itself becomes a function of squark masses through self-energy corrections. We demonstrate that this leads to combined bounds on squark and gluino masses from the limits on chargino, neutralino and Higgs boson masses obtained in the CERN LEP-1 and LEP-1.5 runs. These bounds turn out to be comparable to those obtained from direct searches at the Fermilab Tevatron and may be expected to improve as LEP energies go higher.

title: Signals for R-parity violating supersymmetry at a 500-GeV e+ e- collider
abstract: We investigate the production of charginos and neutralinos at a 500 GeV e + e − collider (NLC) and study their decays to the lightest neutralino, which then decays into multifermion final states through couplings which do not conserve R-parity. These couplings are assumed to affect only the decay of the lightest neutralino. Detailed analyses of the possible signals and backgrounds are performed for five selected points in the parameter space.