714 research outputs found
Auto-antibody profiles in patiens with Diabetes melitus, determined by means of an improved fluorescent antibody microtechnic
Density Perturbations in Heavy-Ion Collisions below the Critical Point
Heavy ion collisions at large baryon density may exhibit a first order phase
transition from a chirally symmetric phase to the symmetry broken ground state.
This should then lead to large density inhomogeneities, which affect the
relative hadron multiplicities.Comment: 1 page, 1 figure, contribution to the GSI annual report 200
Hypernuclei, dibaryon and antinuclei production in high energy heavy ion collisions: Thermal production vs. Coalescence
We study the production of (hyper-)nuclei and di-baryons in most central
heavy Ion collisions at energies of GeV. In particular we are
interested in clusters produced from the hot and dense fireball. The formation
rate of strange and non-strange clusters is estimated by assuming thermal
production from the intermediate phase of the UrQMD-hydro hybrid model and
alternatively by the coalescence mechanism from a hadronic cascade model. Both
model types are compared in detail. For most energies we find that both
approaches agree in their predictions for the yields of the clusters. Only for
very low beam energies, and for di-baryons including 's, we observe
considerable differences. We also study the production of anti-matter clusters
up to top RHIC energies and show that the observation of anti- and even
anti- is feasible. We have found a considerable qualitative
difference in the energy dependence of the strangeness population factor
when comparing the thermal production with the coalescence results.Comment: 9 pages, 8 figures and 2 tables, version accepted by PL
Chemisch aktivierte GlasobjekttrĂ€ger fĂŒr Gefrierschnitte und ihre Anwendung in der Autoantikörperdiagnostik
Probing the density dependence of the symmetry potential in intermediate energy heavy ion collisions
Based on the ultrarelativistic quantum molecular dynamics (UrQMD) model, the effects of the density-dependent symmetry potential for baryons and of the Coulomb potential for produced mesons are investigated for neutron-rich heavy ion collisions at intermediate energies. The calculated results of the Delta-/Delta++ and pi -/pi + production ratios show a clear beam-energy dependence on the density-dependent symmetry potential, which is stronger for the pi -/pi + ratio close to the pion production threshold. The Coulomb potential of the mesons changes the transverse momentum distribution of the pi -/pi + ratio significantly, though it alters only slightly the pi- and pi+ total yields. The pi- yields, especially at midrapidity or at low transverse momenta and the p-/pi+ ratios at low transverse momenta, are shown to be sensitive probes of the density-dependent symmetry potential in dense nuclear matter. The effect of the density-dependent symmetry potential on the production of both, K0 and K+ mesons, is also investigated
From FAIR to RHIC, hyper clusters and an effective strange EoS for QCD
Two major aspects of strange particle physics at the upcoming FAIR and NICA
facilities and the RHIC low energy scan will be discussed. A new distinct
production mechanism for hypernuclei will be presented, namely the production
abundances for hypernuclei from 's absorbed in the spectator matter in
peripheral heavy ion collisions. As strangeness is not uniformly distributed in
the fireball of a heavy ion collision, the properties of the equation of state
therefore depend on the local strangeness fraction. The same, inside neutron
stars strangeness is not conserved and lattice studies on the properties of
finite density QCD usually rely on an expansion of thermodynamic quantities at
zero strange chemical potential, hence at non-zero strange-densities. We will
therefore discuss recent investigations on the EoS of strange-QCD and present
results from an effective EoS of QCD that includes the correct asymptotic
degrees of freedom and a deconfinement and chiral phase transition.Comment: Talk given at the international conference on Strangeness in Quark
Matter 2011 in Krako
Some Comments on Relativistic Hydrodynamics and Fuzzy Bags
Three subjects are considered here: the relativistic hydrodynamics equations
for a boost-invariant expanding fluid; the fuzzy bag model for the pressure
which recently appeared in QCD phenomenology; and the early space-time
evolution of the QCD matter, drawn from model studies, which can also be
expected to arise in realistic fluid dynamics relevant to heavy ion collisions
at LHC.Comment: 10 pages, 5 figures; v3: additional discussion of lattice data, minor
clarifications, references adde
Non-ideal particle distributions from kinetic freeze out models
In fluid dynamical models the freeze out of particles across a three dimensional space-time hypersurface is discussed. The calculation of final momentum distribution of emitted particles is described for freeze out surfaces, with both space-like and time-like normals, taking into account conservation laws across the freeze out discontinuity
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