Biomedical subjects

J Aichelin

Publications and source records attributed to J Aichelin.

At least 19 recordsLinked to original sources

PubMed2005

Critical opacity: a possible explanation of the fast thermalization times seen in BNL RHIC experiments.

The Nambu-Jona-Lasinio Lagrangian offers an explication of the seemingly contradictory observations that (a) the energy loss in the entrance channel of heavy ion reactions is not sufficient to thermalize the system and that (b) the observed hadron cross sections are in almost perfect agreement with hydrodynamical calculations. According to this scenario, a critical opacity develops close to the chiral phase transition which equilibrates and hadronizes the expanding system very effectively. It creates as well radial flow and, if the system is not isotropic, finite upsilon2 values.

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PubMed2004

Novel mechanism of H0 dibaryon production in proton-proton interactions from parton-based Gribov-Regge theory.

A novel mechanism of H0 and strangelet production in hadronic interactions within the Gribov-Regge approach is presented. In this approach the H0 is produced by the same mechanism as usual hadrons, namely, by disintegration of the remnant formed by the exchange of pomerons between the two protons. Rapidity and transverse momentum spectra of the observed hadrons are well described in this approach. In contrast to traditional distillation approaches, here the production of multiple (strange) quark bags does not require large baryon densities or a quark gluon plasma. We calculate the rapidity and transverse momentum distributions as well as the 4pi multiplicity of the H0 for sqrt[s]=17 GeV (Super Proton Synchrotron) and 200 GeV (Relativistic Heavy Ion Collider). In both cases the H0, if it exists, should be observable by the present experiments.

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PubMed2003

What determines the K- multiplicity at energies around (1-2)A GeV?

In heavy ion reactions at energies around (1-2)A GeV the measured K- yields appear rather high as compared to pp collisions as shown by the KaoS Collaboration. Employing quantum molecular dy-namics simulations, we show that this is caused by the fact that the dominant production channel is not BB-->BBK+K- but the mesonic Lambda(Sigma)pi-->K-B reaction. Because the Lambda (Sigma) stem from the reaction BB-->Lambda(Sigma)K+B, the K+ and the K- yield are strongly correlated, i.e., the K(-)/K(+) ratio occurs to be nearly independent of the impact parameter as found experimentally. The final K- yield is strongly influenced by the K+N [due to their production via the Lambda(Sigma)] but very little by the K-N potential.

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PubMed2002

Overpopulation of Omega; in pp collisions: a way to distinguish statistical hadronization from string dynamics.

The Omega/Omega ratio originating from string decays is predicted to be larger than unity in proton-proton interactions at SPS energies ( E(lab) = 160 GeV). The antiomega dominance increases with decreasing beam energy. This surprising behavior is caused by the combinatorics of quark-antiquark production in small and low-mass strings. Since this behavior is not found in a statistical description of hadron production in proton-proton collisions, it may serve as a key observable to probe the hadronization mechanism in such collisions.

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PubMed1996