11 research outputs found
Thermal hadron production in high energy collisions
It is shown that hadron abundances in high energy e+e-, pp and p{\bar p}
collisions, calculated by assuming that particles originate in hadron gas
fireballs at thermal and partial chemical equilibrium, are in very good
agreement with the data. The freeze-out temperature of the hadron gas fireballs
turns out to be nearly constant over a large center of mass energy range and
not dependent on the initial colliding system. The only deviation from chemical
equilibrium resides in the incomplete strangeness phase space saturation.
Preliminary results of an analysis of hadron abundances in S+S and S+Ag heavy
ion collisions are presented.Comment: 10 pages, 1 .eps figure, talk given at the Strangeness and Quark
Matter 97 conferenc
Medium-modified average multiplicity and multiplicity fluctuations in jets
The energy evolution of average multiplicities and multiplicity fluctuations
in jets produced in heavy-ion collisions is investigated from a toy
QCD-inspired model. In this model, we use modified splitting functions
accounting for medium-enhanced radiation of gluons by a fast parton which
propagates through the quark gluon plasma. The leading contribution of the
standard production of soft hadrons is enhanced by a factor while
next-to-leading order (NLO) corrections are suppressed by , where
the parameter accounts for the induced-soft gluons in the medium. Our
results for such global observables are cross-checked and compared with their
limits in the vacuum.Comment: 8 pages and 4 figures. Version to be published in EPJ
Two-loop two-point functions with masses: asymptotic expansions and Taylor series, in any dimension
In all mass cases needed for quark and gluon self-energies, the two-loop
master diagram is expanded at large and small , in dimensions, using
identities derived from integration by parts. Expansions are given, in terms of
hypergeometric series, for all gluon diagrams and for all but one of the quark
diagrams; expansions of the latter are obtained from differential equations.
Pad\'{e} approximants to truncations of the expansions are shown to be of great
utility. As an application, we obtain the two-loop photon self-energy, for all
, and achieve highly accelerated convergence of its expansions in powers of
or , for .Comment: 25 pages, OUT--4102--43, BI--TP/92--5
Bose-Einstein Correlations and Color Reconnection in W-pair production
We propose a systematic study of Bose-Einstein correlations between identical
hadrons coming from different W decays. Experimentally accessible signatures of
these correlations as well as of possible color reconnection effects are
discussed on the basis of two-particle inclusive densities.Comment: 24 pages, 9 eps figures, submitted to Eur. J. Phys.