Experimental studies on gold–gold collisions at RHIC at [Formula: see text] have produced a vast amount of data and results to be analyzed in the light of various competing models in the domain of multiparticle production scenario. We have chosen to analyze here the measured data on the pT-spectra of various light and nonstrange secondaries and some of their very important ratio-behaviors at the various centralities of the collision in the light of a version of the sequential chain model. The agreements between measured data and theoretical plots are found to be modestly satisfactory.

In continuation of our previous works, we attempt here to understand the nature of data on direct photon and neutral pion production in the latest RHIC experiments at [Formula: see text] for all the different interactions studied therein from the viewpoint of a nonstandard outlook and approach as described in Refs. 4 and 5 here. It is found that the proposed model could account for the data-sets with a fair degree of success.

The present paper aims at testing a very simple approach to interpret the characteristics of inclusive production of pions in high energy NA and AA collisions by a somewhat in-depth analysis of the same for NN interactions; and also at reporting here thus some interesting observations made on the nature of rapidity and transverse momentum spectra of the produced pions. And this approach is built upon a newly offered master formula holding the key for converting the results of high energy nucleon–nucleon (NN) collision to the corresponding observables on differential and inclusive cross-sections for both nucleon–nucleus and nucleus–nucleus (heavy ion) collisions in a generalized form. The proposed formulae, used in a somewhat phenomenological way, can provide modestly reliable parametrization of data in the broad range of collision energy and the varied range of projectile-target combinations. This opens up the possibility of understanding in a quite unified manner the large amount of data on the rapidity and transverse momentum spectra in a wide range of interactions and energies starting right from ISR, rather Bevelac, to the relativistic heavy ion collisions (RHIC) via the various collider scales of energy. The agreements between the data and calculations, in most cases, are quite satisfactory both qualitatively and quantitatively. While highlighting this success, the limitation of the approach has also been pointed out in the end as clearly and categorically as possible.

The nature of transverse momentum dependence of the inclusive cross-sections for secondary pions produced in high energy hadronic(P P ), hadronuclear(P A) and nuclear(AA) collisions has here been exhaustively investigated for a varied range of interactions in a unified way with the help of a master formula. This formula evolved from a new combination of the basic Hagedorn's model for particle(pion) production in PP scattering at ISR range of energies, a phenomenological approach proposed by Peitzmann for converting the results of N N (P P ) reactions to those for either P A or AA collisions, and a specific form of parametrization for mass number-dependence of the nuclear cross sections. This grand combination of models(GCM) is then applied to analyse the assorted extensive data on various high energy collisions. The nature of qualitative agreement between measurements and calculations on both the inclusive cross-sections for production of pions, and some ratios of them as well, is quite satisfactory. The modest successes that we achieve here in dealing with the massive data-sets are somewhat encouraging in view of the diversity of the reactions and the very wide range of interaction energies.

The transverse momentum spectra of secondary η particles produced in P + P , D + Au and Au + Au interactions at √ s N N = 200 GeV at different centralities have been studied in the light of a non-extensive thermodynamical approach. The results and the possible thermodynamical insights, thus obtained, about the hadronizing process have also been discussed in detail.