Jets and produced particles in pp collisions from SPS to RHIC energies for nuclear applications

Higher-order pQCD corrections play an important role in the reproduction of data at high transverse momenta in the energy range 20 GeV $\leq \sqrt{s} \leq 200$ GeV. Recent calculations of photon and pion production in $pp$ collisions yield detailed information on the next-to-leading order contributions. However, the application of these results in proton-nucleus and nucleus-nucleus collisions is not straightforward. The study of nuclear effects requires a simplified understanding of the output of these computations. Here we summarize our analysis of recent calculations, aimed at handling the NLO results by introducing process and energy-dependent $K$ factors.Comment: 4 pages with 5 eps figures include

Stability and instability of a hot and dilute nuclear droplet

The diabatic approach to collective nuclear motion is reformulated in the local-density approximation in order to treat the normal modes of a spherical nuclear droplet analytically. In a first application the adiabatic isoscalar modes are studied and results for the eigenvalues of compressional (bulk) and pure surface modes are presented as function of density and temperature inside the droplet, as well as for different mass numbers and for soft and stiff equations of state. We find that the region of bulk instabilities (spinodal regime) is substantially smaller for nuclear droplets than for infinite nuclear matter. For small densities below 30% of normal nuclear matter density and for temperatures below 5 MeV all relevant bulk modes become unstable with the same growth rates. The surface modes have a larger spinodal region, reaching out to densities and temperatures way beyond the spinodal line for bulk instabilities. Essential experimental features of multifragmentation, like fragmentation temperatures and fragment-mass distributions (in particular the power-law behavior) are consistent with the instability properties of an expanding nuclear droplet, and hence with a dynamical fragmentation process within the spinodal regime of bulk and surface modes (spinodal decomposition).Comment: 17 pages, 11 figures, LaTeX2e, EPJA style (included

Multifragmentation calculated with relativistic force

A saturating hamiltonian is presented in a relativistically covariant formalism. The interaction is described by scalar and vector mesons, with coupling strengths adjusted to the nuclear matter. No explicit density depe ndence is assumed. The hamiltonian is applied in a QMD calculation to determine the fragment distribution in O + Br collision at different energies (50 -- 200 MeV/u) to test the applicability of the model at low energies. The results are compared with experiment and with previous non-relativistic calculations. PACS: 25.70Mn, 25.75.+rComment: 23 pages, latex, with 10 PS figures, available at http://www.gsi.de/~papp

K+/pi+ probes of jet quenching in AA collisions

Non-abelian energy loss in quark gluon plasma is shown to lead to novel hadron ratio suppression patterns in ultrarelativistic nuclear collisions. We apply recent (GLV) estimates for the gluon radiative energy loss, which increases linearly with the jet energy up to E<20 GeV and depends quadratically on the nuclear radius, R. The K+/\pi+ ratio is found to be most sensitive to the initial density of the plasma.Comment: Presented at 6th International Conference on Strange Quarks in Matter: 2001: A Flavourspace Odyssey (SQM2001), Frankfurt, Germany, 25-29 Sep 200

Perturbative QCD Results on Pion Production in pp, pA and AA Collisions

We summarize new pQCD results on pion production in proton-proton (pp), proton-nucleus (pA) and nucleus-nucleus (AA) collisions. Our calculation introduces intrinsic parton transverse momentum (k_T) and is performed effectively at next-to-leading order (NLO), applying a K factor extracted for jet events. Two different factorization scales, Q=p_{T,jet}/2 and p_{T,jet} are used. Experimental data in pA collisions imply a preference for the latter choice at NLO level. We display our results at CERN SPS for AA collisions.Comment: Talk given at Budapest Workshop on Quark and Hadron Dynamics in Relativistic Heavy Ion Collisions (BP 2002) Budapest, Hungary, 3-7 Mar 2002. 11 pages in Latex, 7 PS figure. Submitted to Heavy Ion Physic

Is Strangeness Still Strange at the LHC?

Strangeness production is calculated in a pQCD-based model (including nuclear effects) in the high transverse momentum sector, where pQCD is expected to work well. We investigate pion, kaon, proton and lambda production in pp and heavy-ion collisions. Parton energy loss in AA collisions is taken into account. We compare strange-to-non-strange meson and baryon ratios to data at RHIC, and make predictions for the LHC. We find that these ratios significantly deviate from unity not only at RHIC but also at the LHC, indicating the special role of strangeness at both energies.Comment: Contribution to SQM 2007, 6 pages 2 figure

Jet Tomography Studies in AuAu Collision at RHIC Energies

Recent RHIC results on pion production in AuAu collision at sqrt(s)=130 and 200 AGeV display a strong suppression effect at high p_T. This suppression can be connected to final state effects, namely jet energy loss induced by the produced dense colored matter. Applying our pQCD-based parton model we perform a quantitative analysis of the measured suppression pattern and determine the opacity of the produced deconfined matter.Comment: Talk given at European Physical Society International Europhysics Conference on High Energy Physics HEP2003, July 17-23. 2003, in Aachen, Germany 3 pages in LaTeX, 2 EPS figure. (Accepted for publication in European Physical Journal C direct

„Gross-Divina, rendelésre” – a nagydivényi meteorit másolatának elkészítése 3D-nyomtatással (a meteorithullás és a példány rövid történetével) = “Gross-Divina on demand” – making of a meteorite replica by 3D printing (with a brief history of the meteorite fall and the specimen)

A 3D-printed replica of the main mass of the Gross-Divina meteorite, kept in the collection of the Department of Mineralogy and Petrology of the Hungarian Natural History Museum,has been prepared in the framework of a Slovak meteoritic project. Th is 3D-printed meteorite replica is among the fi rst of its kind produced worldwide, therefore some details of the scanning and printing process are given and the experiences of the project are summarised here. Data on the acquisition and research history of the specimen, collected in connection with the project, are briefl y reviewed and some physical data (size, weight, volume density) of the specimen (re)determined are reported. With 4 fi gures