Study of multiparticle spikes in central 4.5A GeV/c C-Cu collisions

Abstract

An analysis of local fluctuations, or spikes, is performed for charged particles produced in central C-Cu collisions at 4.5 GeV/c/nucleon. The distributions of spike-centers and the maximum density distributions are investigated for different narrow pseudorapidity windows to search for multiparticle dynamical correlations. Two peaks over statistical background are observed in the spike-center distributions with the structure similar to that expected from the coherent gluon radiation model and recently found in hadronic interactions. The dynamical contribution to maximum density fluctuations are obtained to be hidden by statistical correlations, though behavior of the distributions shows qualitative agreement with that from the one-dimensional intermittency model. The observed features of the two different approaches, coherent vs. stochastic, to the formation of the local dynamical fluctuations are discussed.

On coherent particle production in central 4.3A GeV/c Mg–Mg collisions

“…A two-peak structure of the measured distributions (solid circles) with the peaks in the neighbourhood of the same ∼ η 0 is seen independent of the width and multiplicity of spike. The shape of the distributions is in agreement with the structure predicted by the coherent gluon-jet emission model [4] and is similar to that observed earlier in hadronic interactions [5] and by us in C-Cu collisions [6].…”

“…pp interactions). Recent observations in hadronic [5] and nuclear [6] interactions are found to be in agreement with these predictions.…”

Multiparticle Production at High Multiplicities

“…At the same time the particle distribution at the azimuthal angle is uniform. Study of the spike center distribution [19] in central C-Cu collisions at 4.5 GeV/c/A (all charged particles) and Mg-Mg collisions at 4.3 GeV/c/A (only negative charged particles) were found to be in agreement with the hypothesis of mesonic Cherenkov radiation. For this goal it was used transformation of pseudorapidity spectra from η variable to η with the uniform spectrum.…”

The quark–gluon medium

“…Moreover, the absorption may be strong enough and hadronization (confinement) may change the final characteristics. The very first experimental indication in 1979 [137] which favored this effect dealt with a single cosmic ray event (also some others less pronounced were observed in cosmic rays and at lower energies in emulsion experiments at accelerators [144,145,146,147,148,149,150,151,152,153,154,155,156,157,189]).…”