Power series distributions in clan structure analysis: new observables in strong interactions

We present a new thermodynamical approach to multiparticle production in high energy hadronic interactions, making use of the formalism of infinitely divisible power series distributions. This approach allows us to define new observables, linked to the system fugacity, which characterise different classes of events.Comment: 9 pages, 2 figures, talk presented by R. Ugoccioni at "Correlations and Fluctuations 2002", Crete, Greece, 8-15 June 200

Forward-backward multiplicity correlations in e+e- annihilation and pp collisions and the weighted superposition mechanism

Forward-backward multiplicity correlations in symmetric collisions are calculated independently of the detailed form of the corresponding multiplicity distribution. Applications of these calculations to e+e- annihilation and ppbar collisions confirm the existence of the weighted superposition mechanism of different classes of substructures or components. When applied to ppbar collisions in particular, clan concept and its particle leakage from one hemisphere to the opposite one become of fundamental importance. The increase with c.m. energy of the correlation strength as well as the behaviour of the average number of backward particles vs. the number of forward particles are correctly reproduced.Comment: 8 pages, 2 figures, talk presented by A. Giovannini at "Correlations and Fluctuations 2002", Crete, Greece, 8-15 June 200

Large Scale Structure and Cosmic Rays revisited

We investigate the possibility that ultra high energy cosmic rays (E > 10^19 eV) are related to the distribution of matter on large scales. The large scale structure (LSS) data stems from the recent IRAS PSCz redshift survey. We present preliminary predictions drawn from an anisotropic distribution of sources which follows the galaxy distribution.Comment: 6 pages, 2 figures, uses World Scientific style. To appear in the proceedings of "Third International Workshop on New Worlds in Astro-Particle Physics", 1-3 Set. 2000, Faro, Portugal and X ENAA, 27-28 Jul. 2000, Lisbon, Portuga

Maps of zeroes of the grand canonical partition function in a statistical model of high energy collisions

Theorems on zeroes of the truncated generating function in the complex plane are reviewed. When examined in the framework of a statistical model of high energy collisions based on the negative binomial (Pascal) multiplicity distribution, these results lead to maps of zeroes of the grand canonical partition function which allow to interpret in a novel way different classes of events in pp collisions at LHC c.m. energies.Comment: 17 pages, figures (ps included); added references, some figures enlarged. To appear in J. Phys.

Particle rapidity density and collective phenomena in heavy ion collisions

We analyse recent results on charged particle pseudo-rapidity densities from RHIC in the framework of the Dual String Model, in particular when including string fusion. The model, in a simple way, agrees with all the existing data and is consistent with the presence of the percolation transition to the Quark-Gluon Plasma already at the CERN-SPS. It leads to strict saturation of the particle (pseudo-)rapidity density, normalised to the number of participant nucleons, as that number increases. A comparison with recent WA98 data is presented.Comment: 6 pages, 3 ps figures, Latex2e with amsmath. To appear in the Proceedings of the XXX International Symposium on Multiparticle Dynamics (Lake Balaton, October 2000

Absorption and percolation in the production of J/psi in heavy ion collisions

We present a simple model with string absorption and percolation to describe the J/psi suppression in heavy ion collisions. The NA50 data are fairly well explained by the model.Comment: 6 pages, 3 postscript figures include

Open problems in forward-backward multiplicity correlations in hadron-hadron collisions in the TeV region

Continuing previous work on forward-backward multiplicity correlation properties in proton-proton collisions in the framework of the weighted superposition model of two components (each one described by a negative binomial multiplicity distribution) with the addition of the leakage parameter which controls clan spreading from one hemisphere to the opposite one, we examine E735 data on the c.m. energy dependence of the total correlation strength and of the forward variance at fixed total multiplicity. A comparison with the Chou-Yang approach to the problem is presented and extrapolations of the mentioned variables at LHC c.m. energy in possible scenarios in the new energy domain are discussed

Oscillations of Moments and Structure of Multiplicity Distributions in e+e- Annihilation

Starting from the recognized fact that oscillations of moments with rank and shoulder structure in the multiplicity distribution have the same origin in the full sample of events in e+e- annihilation, we push our investigation to the 2-jet sample level, and argue in favor of the use of the negative binomial multiplicity distribution as the building block of multiparticle production in e+e- annihilation events. It will be shown that this approach leads to definite predictions for the correlation structure, e.g., that correlations are flavour independent.Comment: 6 pages, LaTeX2e (uses amsmath,epsfig,espcrc2), 4 postscript figures. To be published in the Proceedings of the XXVII International Symposium on Multiparticle Dynamics, Frascati (Italy), September 8--12, 199