Constituent Quark Scaling of Strangeness Enhancement in Heavy-Ion Collisions

In the frame work of a nuclear overlap model, we estimate the number of nucleon and quark participants in proton-proton, proton-nucleus and nucleus-nucleus collisions. We observe the number of nucleon ($N_{N-part}$)-normalized enhancement of multi-strange particles which show a monotonic increase with centrality, turns out to be a centrality independent scaling behavior when normalized to number of constituent quarks participating in the collision ($N_{q-part}$). In addition, we observe that the $N_{q-part}$-normalized enhancement, when further normalized to the strangeness content, shows a strangeness independent scaling behavior. This holds good at top RHIC energy. However, the corresponding SPS data show a weak $N_{q-part}$-scaling with strangeness scaling being violated at top SPS energy. This scaling at RHIC indicates that the partonic degrees of freedom playing an important role in the production of multi-strange particles. Top SPS energy, in view of the above observations, shows a co-existence of hadronic and partonic phases. We give a comparison of data with HIJING, AMPT and UrQMD models to understand the particle production dynamics at different energies.Comment: 9 pages, 17 figure

Charged Particle and Photon Multiplicity, and Transverse Energy Production in High-Energy Heavy-Ion Collisions

We review the charged particle and photon multiplicity, and transverse energy production in heavy-ion collisions starting from few GeV to TeV energies. The experimental results of pseudorapidity distribution of charged particles and photons at different collision energies and centralities are discussed. We also discuss the hypothesis of limiting fragmentation and expansion dynamics using the Landau hydrodynamics and the underlying physics. Meanwhile, we present the estimation of initial energy density multiplied with formation time as a function of different collision energies and centralities. In the end, the transverse energy per charged particle in connection with the chemical freeze-out criteria is discussed. We invoke various models and phenomenological arguments to interpret and characterize the fireball created in heavy-ion collisions. This review overall provides a scope to understand the heavy-ion collision data and a possible formation of a deconfined phase of partons via the global observables like charged particles, photons and the transverse energy measurement.Comment: 27 pages, 43 figures, Invited Review for Advances in High Energy physics for Special Issue on "Global properties in High Energy Collisions

Effective-energy budget in multiparticle production in nuclear collisions

The dependencies of charged particle pseudorapidity density and transverse energy pseudorapidity density at midrapidity on the collision energy and on the number of nucleon participants, or centrality, measured in nucleus-nucleus collisions are studied in the energy range spanning a few GeV to a few TeV per nucleon. The model in which the multiparticle production is driven by the dissipating effective energy of participants is introduced. The model is based on the earlier proposed approach, combining the constituent quark picture together with Landau relativistic hydrodynamics shown to interrelate the measurements from different types of collisions. Within this model, the dependence on the number of participants in heavy-ion collisions are found to be well described in terms of the effective energy defined as a centrality-dependent fraction of the collision energy. For both variables under study, the effective energy approach reveals a similarity in the energy dependence obtained for the most central collisions and centrality data in the entire available energy range. Predictions are made for the investigated dependencies for the forthcoming higher energy measurements in heavy-ion collisions at the LHC.Comment: Regular article, Replaced with published versio

Biochemical Changes during Gonadal Maturation Portunus pelagicus (Linnaeus, 1758)

The changes in moisture, protein, lipid, carbohydrate and carotenoids in the ovary, hepatopancreas, muscle and haemolymph during the process of gonadal maturation of the crab PorhmllS pelagiclls (Linnaeus, 1758) were nvestigated. There was significant difference (p<O.Ol) in moisture, protein and carotenoid levels at various maturity stages. The lipid content showed significant difference (p<O.Ol) in all the tissues except in muscle tissue and the carbohydrate values showed significant difference (p<O.01) only for ovary and hepatopancreas. The moisture content decreased with gonadal maturation in all the tissues. The protein titre increased with maturity in ovary, muscle and haemolymph whereas in hepatopancreas it registered a decrease. The lipid values of all the tissues and the haemolymph showed an v increasing trend with maturation. The carbohydrate level also increased with gonadal maturity in the tissues and haemolymph. The carotenoid content followed an increasing trend till mature stage in the ovary whereas in the hepatopancreas and haemolymph it increased till the late maturing stage

Effective-energy universality approach describing total multiplicity centrality dependence in heavy-ion collisions

The recently proposed participant dissipating effective-energy approach is applied to describe the dependence on centrality of the multiplicity of charged particles measured in heavy-ion collisions at the collision energies up to the highest LHC energy of 5 TeV. The effective-energy approach relates multihadron production in different types of collisions, by combining, under the proper collision energy scaling, the constituent quark picture with Landau relativistic hydrodynamics. The measurements are shown to be well described in terms of the centrality-dependent effective energy of participants and an explanation of the differences in the measurements at RHIC and LHC are given by means of the recently introduced hypothesis of the energy-balanced limiting fragmentation scaling. A similarity between the centrality data and the data from most central collisions is proposed pointing to the central character of participant interactions independent of centrality. The findings complement our recent investigations of the similar midrapidity pseudorapidity density measurements extending the description to the full pseudorapidity range in view of the considered similarity of multihadron production in nucleon interactions and heavy-ion collisions.Comment: Same as published versio