Moduli stabilization in (string) model building: gauge fluxes and loops

We discuss the moduli stabilization arising in the presence of gauge fluxes, R-symmetry twists and non-perturbative effects in the context of 6-dimensional supergravity models. We show how the presence of D-terms, due to the gauge fluxes, is compatible with gaugino condensation, and that the two effects, combined with the R-symmetry twist, do stabilize all the Kaehler moduli present in the model, in the spirit of KKLT. We also calculate the flux-induced one-loop correction to the scalar potential coming from charged hypermultiplets, and find that it does not destabilize the minimum.Comment: Submitted for the SUSY07 proceedings, 4 pages, LaTe

The horn, the hadron mass spectrum and the QCD phase diagram - the statistical model of hadron production in central nucleus-nucleus collisions

We present the status of the description of hadron production in central nucleus-nucleus collisions within the statistical model . The recent inclusion of very high-mass resonances and the sigma meson leads to an improved description of the data, in particular the energy dependence of the K+/pi+ ratio at SPS energies (``the horn''). The connection to the QCD phase diagram is discussed.Comment: 4 pages, 3 figures; presented at the Nucleus-Nucleus 2009 conference, Beijing, Aug. 200

ΔπN\Delta\pi N coupling constant in light cone QCD sum rules

We employ the light cone QCD sum rules to calculate $\Delta\pi N$ coupling constant by studying the two point correlation function between the vacuum and the pion state. Our result is consistent with the traditional QCD sum rules calculations and it is in agreement with the experimental value.Comment: 8 pages, latex, 2 figure

The thermal model on the verge of the ultimate test: particle production in Pb-Pb collisions at the LHC

We investigate the production of hadrons in nuclear collisions within the framework of the thermal (or statistical hadronization) model. We discuss both the ligh-quark hadrons as well as charmonium and provide predictions for the LHC energy. Even as its exact magnitude is dependent on the charm production cross section, not yet measured in Pb-Pb collisions, we can confidently predict that at the LHC the nuclear modification factor of charmonium as a function of centrality is larger than that observed at RHIC and compare the experimental results to these predictions.Comment: 4 pages, 3 figures; proceedings of QM201

Statistical hadronization of charm at SPS, RHIC and LHC

We study the production of charmonia and charmed hadrons for nucleus-nucleus collisions at SPS, RHIC, and LHC energies within the framework of the statistical hadronization model. Results from this model are compared to the observed centrality dependence of J/psi production at SPS energy. We further provide predictions for the centrality dependence of the production of open and hidden charm mesons at RHIC and LHC.Comment: Contribution to Quark Matter 2002, 4 pages, 3 figures; revised version including charmed hyperons (omitted in v1

The statistical model in Pb-Pb collisions at the LHC

We briefly review the predictions of the thermal model for hadron production in comparison to latest data from RHIC and extrapolate the calculations to LHC energy. Our main emphasis is to confront the model predictions with the recently released data from ALICE at the LHC. This comparison reveals an apparent anomaly for protons and anti-protons which we discuss briefly. We also demonstrate that our statistical hadronization predictions for J/$\psi$ production agree very well with the most recent LHC data, lending support to the picture in which there is complete charmonium melting in the quark-gluon plasma (QGP) followed by statistical generation of J/$\psi$ mesons at the phase boundary.Comment: 4 pages, 3 figures, proceedings of QM201

Open charm contribution to dilepton spectra produced in nuclear collisions at SPS energies

Measurements of open charm hadro-production from CERN and Fermilab experiments are reviewed, with particular emphasis on the absolute cross sections and on their A and sqrt(s) dependences. Differential pt and xf cross sections calculated with the Pythia event generator are found to be in reasonable agreement with recent data. The calculations are scaled to nucleus-nucleus collisions and the expected lepton pair yield is deduced. The charm contribution to the low mass dilepton continuum observed by the CERES experiment is found to be negligible. In particular, it is shown that the observed low mass dilepton excess in S-Au collisions cannot be explained by charm enhancement.Comment: 19 pages, 12 eps figures included. To be published in Z.Phys.