Charged-particle multiplicity distributions in different rapidity windows in 800 GeV proton-nucleus interactions

Multiplicity distributions of charged particles produced in interactions of 800 GeV protons with emulsion nuclei in various rapidity windows are presented. The data is also analyzed separately for the forward and the backward hemispheres, for rapidity windows of different widths. It is found that the Negative Binomial Distribution (NBD) describes well the multiplicity distribution of secondary particles in various rapidity windows and also in both the hemispheres. We have compared the NBD parameters, in both the hemispheres, at 200 GeV and 360 GeV, with those at 800 GeV. The behaviour of NBD parameters in rapidity windows of different widths and for different targets has also been studied. Received: 30 August 2001 / Accepted: 28 January 2002     

Dispersion of the multiplicity distribution in hadron-nucleus collisions

It is argued that the measurements of the dispersion of the multiplicity distribution in hadron-nucleus collisions favour the processes of particle production in a sequence of collisions of the incident hadron with target nucleons. On the other hand, generation of particles on groups of nucleons treated as single units leads to large discrepancies.     

Evidence of self-affine multiplicity scaling of charged-particle multiplicity distribution in hadron-nucleus interaction

A self-affine analysis of charged-particle multiplicity distribution (protons + pions) in π ⁻-AgBr interaction at 350 GeV/c is performed according to the two-dimensional factorial moment methodology using the concept of Hurst exponent in X _cosθ -X _ϕ phase space. Comparing with the results obtained from self-similar analysis, the self-affine analysis shows a better power-law behaviour. Corresponding results are compared with shower multiplicity distribution (pions). Multifractal behaviour is observed for both types of distributions.      

Charged-particle multiplicity distribution ine + e − collision at 29 GeV

The charged-particle multiplicity distribution and forward-backward correlation ofe ⁺ e ^? annihilation at 29 GeV are discussed on the basis of a mixed two-component model.     

Consequences of hadron-nucleus multiplicity parametrization

Some interesting consequences are analyzed of a new parametrization for the hadron-nucleus multiplicity distributions and they are compared with the experimental data. Further, it is illustrated how the scaling property for the average multiplicity will be modified and it is found that the experimental data support this behaviour.     

Role of the cascade interactions on the multiplicity distribution in hadron-nucleus collisions

Multiplicity distribution in proton-nucleus (p-A) collisions are investigated by the use of the Monte Carlo event generator MCMHA which has been developed based on the multi-chain model. The comparisons between the calculational results of MCMHA and the data are made through the parameters of negative binomial distributions. We can find nice agreement between them. The interpretation for the difference in the behaviour of 1/k in the backward hemisphere between \(p(\bar p) - p\) andp-A collisions is presented. In this connection, we also discuss the multiplicity ration 〈N〉 _pA /〈N〉 _pN .     

Inclusive two-and three-particle rapidity correlations in high-energy hadron-nucleus collisions

Three-particle pseudorapidity correlations are investigated for relativistic secondaries from proton-nucleus interactions at 50, 67, 200 and 400 GeV/c and from pion-nucleus interactions at 50 and 200 GeV/c. The experimental data on two- and three-particle correlations are compared with quantitative predictions of current multiple scattering models of nuclear production. Within these models the influence of various factors on the magnitude of correlations is discussed and it is shown, in particular, that energy-momentum conservation plays an essential role at present accelerator energies.     

Reaction filters. Charged-particle multiplicity and linear momentum transfer

The relation between charged-particle multiplicity and linear momentum transfer to heavy reaction residues has been investigated with a 4π charged-particle detector for the reactions ³⁶Ar+²³⁸U at E/A=35 MeV and ¹⁴N+²³⁸U at E/A=50 MeV. The multiplicity of charged particles at backward angles (θ > 35°) incrreases linear momentum transfer while the multiplicity of charged particles in the forward direction is almost independent of the linear momentum transfer.     

Charged-particle multiplicity at mid-rapidity in Au-Au collisions at relativistic heavy-ion collider

The particle density at mid-rapidity is an essential global variable for the characterization of nuclear collisions at ultra-relativistic energies. It provides information about the initial conditions and energy density reached in these collisions. The pseudorapidity densities of charged particles at mid-rapidity in AuAu collisions at √^s _NN = 130 and 200 GeV at RHIC (relativistic heavy ion collider) have been measured with the PHENIX detector. The measurements were performed using sets of wire-chambers with pad readout in the two central PHENIX tracking arms. Each arm covers one quarter of the azimuth in the pseudorapidity interval |η| < 035. Data is presented and compared with results from proton-proton collisions and nucleus-nucleus collisions at lower energies. Extrapolations to LHC energies are discussed.     

Inclusive hadron-nucleus scattering at high energy

The multiple scattering series of Glauber and Matthiae for hadron-nucleus scattering is summed to a simple analytical expression. It reproduces quantitatively the main features of the experimental cross section for the reaction ${}^4\text{He}\text{+}{}^{\mathrm{A}}\text{Z →}{}^4\text{He + X}$ at 1 GeV/nucleon.     

Topological cross-section in hadron-nucleus collisions and multiple scattering theory

The multiple scattering theory supplemented with AGK cutting rules is applied to calculation of the hadron-nucleus interaction cross-sections. In contrast to standard Glauber approach neither smallness of the interaction radius compared to the nuclear radii nor Gaussian form of thehN-interaction profile function are assumed. We consistently use the theory of the supercritical Pomeron. However all the results are more general and do not depend on the specific parametrization of the Pomeron pole ampletude. The region of validity of the widely used approximate formulae for topological and totalhA-interaction cross sections are discussed. It is discussed the novel features of particle-nucleus interactions at superhigh energies.     

Target mass dependence of mean slow particle multiplicity in high energy hadron-nucleus interaction

This work presents a study on the dependence of mean slow particle multiplicity (N_h) on the mass numberA of the target nucleus for a wide range of target mass and energy. It has been shown that this dependence can be best expressed by the relation N _h= 0.57A^0.61.The author would like to express his indebtedness to Prof. A. Herz (CERN), Prof. K. D. Tolostov (JINR), Prof. R. Wilkes (University of Washington) for kindly supplying the exposed emulsion plates.     

Analysis of shower particle multiplicity in hadron-nucleus collisions in the few hundred GeV region

An analysis of relativistic charged secondaries produced in hadron-nucleus collisions in the few hundred GeV region is presented from the point of view of the structure of hadrons and to examine the possibility of discriminating different theoretical models. An attempt has been made to study the mean normalised multiplicity ratio in the central region and its dependence on the mean number of intranuclear collisionsv. The rate of increase in the production of particles exhibits good agreement with our proposed approach of the constituent supercluster model.     

Leading charges and charged particle distributions in limited rapidity bins

The effect of leading charges in negative and charged particle distributions in limited rapidity bins is discussed with particular emphasis on the extent in rapidity of strong charge correlations.     

Finite-energy corrections and multiplicity fluctuations according to the Gottfried model of hadron-nucleus interactions

Finite-energy corrections and multiplicity fluctuations are considered in the Gottfried model for hadron-nucleus high-energy interactions. The results are that there are appreciable corrections at Serpukhov-NAL energies, such that the Gottfried parameter is ν = 0.25–0.27 instead of, e.g., ν = 0.38, in better agreement with presently available experimental results for proton-nucleus collisions. Further, the sensitivity of the model to some of the input parameters results in appreciable fluctuations in multiplicity, the multiplicity distribution of the part stemming from repeated collisions inside the nucleus being at least as broad as a Poisson distribution.     

Implications of the Glauber model for inelastic hadron-nucleus scattering

The Glauber model for elastic hadron-nucleus scattering is extended to inelastic processes by supplementing it with the Abramovskii, Gribov, Kancheli cutting rules. Inelastic screening due to low mass states is also included. The results can be interpreted in terms of the probabilistic multiple collision model. The mutual relationship of the two approaches is discussed.     

Molecular light scattering of multiplicity 1.5

The “interference” contributions from compact groups of scattering centers to the total intensity of molecular scattering in a liquid are analyzed. The result of the algebra of fluctuating quantities has been restored for the case of long-range correlations between the groups. The role of short-range correlations is most significant for moderate deviations (10^?3?10^?2) of the dimensionless temperature from its critical value. Estimates of the relative value and temperature peculiarities of the contributions of multiplicity 1.5 proportional to the third-order moment of the density fluctuations and an analysis of experimental data indicate that they can be partially observed under conditions deviating from the critical isochore.