3,057 research outputs found
Heavy ion collisions in the used nucleon model
It is shown that recently proposed by R.J. Glauber the used nucleon model
combined with the assumption that the nucleon consists of two constituents (a
quark and a diquark) describes well the PHOBOS data on particle production at
midrapidity.Comment: 5 pages, 2 figure
Wounded quarks and diquarks in heavy ion collisions
A model in which the soft collisions of the nucleon are described in terms of
interactions of its two constituents (a quark and a diquark) is proposed. When
adjusted to describe precisely the elastic proton-proton scattering data and
supplemented with the idea of wounded constituents, the model accounts rather
well for the centrality dependence of particle production in the central
rapidity region at RHIC energies.Comment: 8 pages, 4 figures, added references; corrected typo in Eq. (15
The Renyi entropy H_2 as a rigorous, measurable lower bound for the entropy of the interaction region in multiparticle production processes
A model-independent lower bound on the entropy S of the multiparticle system
produced in high energy collisions, provided by the Renyi entropy H_2, is shown
to be very effective. Estimates show that the ratio H_2/S remains close to one
half for all realistic values of the parameters.Comment: Eur. Phys. J. C in print, 17 pages, 5 figure
Matter Correlations in Branched Polymers
We analyze correlation functions in a toy model of a random geometry
interacting with matter. We show that in general the connected correlator will
contain a long--range scaling part. This result supports the previously
conjectured general form of correlation functions on random geometries. We
discuss the interplay between matter and geometry and the role of the symmetry
in the matter sector.Comment: 20 page
Moments of Wigner function and Renyi entropies at freeze-out
Relation between Renyi entropies and moments of the Wigner function,
representing the quantum mechanical description of the M-particle
semi-inclusive distribution at freeze-out, is investigated. It is shown that in
the limit of infinite volume of the system, the classical and quantum
descriptions are equivalent. Finite volume corrections are derived and shown to
be small for systems encountered in relativistic heavy ion collisions.Comment: 15 pages, one figur
Dimensional reduction and a Z(3) symmetric model
We present first results from a numerical investigation of a Z(3) symmetric
model based on dimensional reduction.Comment: Talk presented at XXI International Symposium on Lattice Field Theory
lattice2003(Non-zero temperature and density
Bose-Einstein correlations
The effect of Bose-Einstein correlations on multiplicity distributions of
identical pions is discussed. It is found that these correlations affect
significantly the observed multiplicity distributions, but Einstein's
condensation is unlikely to be achieved, unless "cold spots", i.e. regions,
where groups of pions with very small relative momenta are produced, occur in
high energy heavy-ion collisions.Comment: 8 pages Latex, no figures, Conference QCD99, Montpellier July 199
Forward-backward multiplicity correlations in the wounded nucleon model
The forward-backward multiplicity correlation strength is calculated for
arbitrary nucleus-nucleus collision in the framework of the wounded nucleon
model. Discussion of our results in the context of the recent STAR data in
Au+Au collisions at sqrt{s}=200 GeV is presented. It is suggested that the
observed (i) growth of the correlation coefficient with centrality and (ii)
approximately flat pseudorapidity dependence of the correlation strength for
central collisions are due to the fluctuations of the number of wounded
nucleons at a given centrality bin.Comment: 15 pages, 4 figures, accepted for publication in Phys. Rev. C.
Changed content: STAR data included, extended discussion, added reference
Coincidence probability as a measure of the average phase-space density at freeze-out
It is pointed out that the average semi-inclusive particle phase-space
density at freeze-out can be determined from the coincidence probability of the
events observed in multiparticle production. The method of measurement is
described and its accuracy examined.Comment: LateX, 9 pages, no figure
Balls in Boxes and Quantum Gravity
Four dimensional simplicial gravity has been studied by means of Monte Carlo
simulations for some time, the main outcome of the studies being that the model
undergoes a discontinuous phase transition between an elongated and a crumpled
phase when one changes the curvature (Newton) coupling. In the crumpled phase
there are singular vertices growing extensively with the volume of the system
whereas the elongated phase resembles a branched-polymer.
We have postulated that this behaviour is a manifestation of the
constrained-mean-field scenario as realised in the Branched Polymer or
Balls-in-Boxes model. These models share all the features of 4D simplicial
gravity except that they exhibit a continuous phase transition. We note here
that this defect can be remedied by a suitable choice of ensemble.Comment: 3 pages, LaTeX, 2 figures, uses espcrc2.sty, talk given at LATTICE9
- …