8 research outputs found
Transverse Momentum Spectra of Pions in Particle and Nuclear Collisions and Some Ratio-Behaviours: Towards A Combinational Approach
The nature of transverse momentum dependence of the inclusive cross-sections
for secondary pions produced in high energy hadronic(), hadronuclear()
and nuclear() 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
reactions to those for either or 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.Comment: 19 pages, 19 figure
Interpretations of suppression
We review the two main interpretations of suppression proposed in
the literature. The phase transition (or deconfining) scenario assumes that
below some critical value of the local energy density (or of some other
geometrical quantity which depends both on the colliding systems and on the
centrality of the collision), there is only nuclear absorption. Above this
critical value the absorptive cross-section is taken to be infinite, i.e. no
can survive in this hot region. In the hadronic scenario the
dissociates due both to nuclear absorption and to its interactions with
co-moving hadrons produced in the collision. No discontinuity exists in
physical observables. We show that an equally good description of the present
data is possible in either scenario.Comment: 12 pages, LaTeX, uses epsfig and ioplppt; review talk given by A.
Capella at the International Symposium on Strangness in Quark Matter,
Santorini (Greece), April 1997; Figs. 1 and 2 not available but can be found
in Refs. 13 and 6 respectivel
High Precision and -production data and the Nuclear Glue
We use the high statistics E-772 data on the nuclear dependence of the
production of quarkonia and and dimuons at large
transverse momentum in - collisions to get information about the
gluonic EMC effect. We find a satisfactory quantitative agreement of the
theoretical predictions with the data although none of the models of the EMC
effect we consider could account for the entire data. Since all the qualitative
features are understood none the less in terms of perturbative QCD with nuclear
dependent parton densities, our results suggest that these data can now be used
for a better determination of the nuclear parton densities. Our conslusions are
shown to be insensitive to the hadronisation mechanism for the quarkonia.Comment: 28 pages, 8 Figures (included as uuencoded figs.uu file at the end),
RevTeX, TIFR/TH/93-57, BU-TH-93/
Medium effects in high energy heavy-ion collisions
The change of hadron properties in dense matter based on various theoretical
approaches are reviewed. Incorporating these medium effects in the relativistic
transport model, which treats consistently the change of hadron masses and
energies in dense matter via the scalar and vector fields, heavy-ion collisions
at energies available from SIS/GSI, AGS/BNL, and SPS/CERN are studied. This
model is seen to provide satisfactory explanations for the observed enhancement
of kaon, antikaon, and antiproton yields as well as soft pions in the
transverse direction from the SIS experiments. In the AGS heavy-ion
experiments, it can account for the enhanced ratio, the difference
in the slope parameters of the and transverse kinetic energy
spectra, and the lower apparent temperature of antiprotons than that of
protons. This model also provides possible explanations for the observed
enhancement of low-mass dileptons, phi mesons, and antilambdas in heavy-ion
collisions at SPS energies. Furthermore, the change of hadron properties in hot
dense matter leads to new signatures of the quark-gluon plasma to hadronic
matter transition in future ultrarelativistic heavy-ion collisions at RHIC/BNL.Comment: RevTeX, 65 pages, including 25 postscript figures, invited topical
review for Journal of Physics G: Nuclear and Particle Physic
Ψ′ and J/Ψ production in p-W, p-U and S-U interactions at 200 GeV/nucleon
[[sponsorship]]物理研究所[[note]]已出版;[SCI];有審查制度;具代表性[[note]]http://gateway.isiknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=Drexel&SrcApp=hagerty_opac&KeyRecord=0370-2693&DestApp=JCR&RQ=IF_CAT_BOXPLO
Muon pair and vector meson cross-sections in p-W and S-U collisions at 200 GeV/nucleon
[[sponsorship]]物理研究所[[note]]已出版;[SCI];有審查制度;具代表性[[note]]http://gateway.isiknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=Drexel&SrcApp=hagerty_opac&KeyRecord=0370-2693&DestApp=JCR&RQ=IF_CAT_BOXPLO
Psi' and J/Psi production in p-U and S-U collisions at 200 GeV/Nucleon
[[sponsorship]]物理研究所[[note]]已出版;[SCI];有審查制度;具代表性[[note]]http://gateway.isiknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=Drexel&SrcApp=hagerty_opac&KeyRecord=0370-2693&DestApp=JCR&RQ=IF_CAT_BOXPLO
Colour deconfinement in nuclear collisions
Satz H. Colour deconfinement in nuclear collisions. Reports on Progress in Physics. 2000;63(9):1511-1574.QCD predicts that strongly interacting matter will undergo a transition from a state of hadronic constituents to a plasma of unbound quarks and gluons. We first survey the conceptual features of this transition and its description in finite temperature lattice QCD, before we address its experimental investigation through high energy nucleus-nucleus collisions. After surveying the conditions achievable in such collisions, we discuss the possible probes to check if the produced medium in its early stages was indeed deconfined. We then elaborate the method that has emerged and the results which were obtained using the most extensively studied deconfinement probe, the suppression of charmonium production. In closing, we discuss possible corroborative information provided through the study of soft hadronic probes