896 research outputs found
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
Jet Transport Coefficient at the Large Hadron Collider Energies in a Color String Percolation Approach
Within the color string percolation model (CSPM), jet transport coefficient,
, is calculated for various multiplicity classes in proton-proton and
for centrality classes in nucleus-nucleus collisions at the Large Hadron
Collider energies for a better understanding of the matter formed in
ultra-relativistic collisions. is studied as a function of final
state charged particle multiplicity, initial state percolation temperature and
energy density. The CSPM results are then compared with different theoretical
calculations from the JET collaboration those incorporate particle energy loss
in the medium. A good agreement is found between CSPM results and the JET
collaboration calculations.Comment: 8 pages and 7 figures, Submitted for publicatio
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
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
Energy and Centrality dependence of and in Heavy-Ion Collisions from =7.7 GeV to 5.02 TeV
The centrality dependence of pseudorapidity density of charged particles and
transverse energy is studied for a wide range of collision energies for
heavy-ion collisions at midrapidity from 7.7 GeV to 5.02 TeV. A two-component
model approach has been adopted to quantify the soft and hard components of
particle production, coming from nucleon participants and binary
nucleon-nucleon collisions, respectively. Within experimental uncertainties,
the hard component contributing to the particle production has been found not
to show any clear collision energy dependence from RHIC to LHC. The effect of
centrality and collision energy in particle production seem to factor out with
some degree of dependency on the collision species. The collision of
Uranium-like deformed nuclei opens up new challenges in understanding the
energy-centrality factorization, which is evident from the centrality
dependence of transverse energy density, when compared to collision of
symmetric nuclei.Comment: Published version in Eur. Phys. J.
Corrigendum to “Charged Particle, Photon Multiplicity, and Transverse Energy Production in High-Energy Heavy-Ion Collisions”
- …