96 research outputs found
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
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