Proton/pion ratios and radial flow in pp and peripheral heavy ion collisions

The production of baryon and mesons in the RHIC heavy-ion experiments has received a lot of attention lately. Although not widely known, the pp data measured concurrently with heavy ion collisions do not find a convincing explanation in terms of simple models. We present the results of an afterburner to Pythia and Hijing event generators, simulating radial flow which seems to qualitatively explain the experimental results when applied to the pp collision data from RHIC at 200 GeV center-of-mass energy.Comment: 4 page, 5 figures. Prepared for X Mexican Workshop on Particles and Filed, Morelia Michoacan, November 7-17,2005. Referenced was corrected. Section 2, a sentence was modifie

Event Shape Analysis in ALICE

The jets are the final state manifestation of the hard parton scattering. Since at LHC energies the production of hard processes in proton-proton collisions will be copious and varied, it is important to develop methods to identify them through the study of their final states. In the present work we describe a method based on the use of some shape variables to discriminate events according their topologies. A very attractive feature of this analysis is the possibility of using the tracking information of the TPC+ITS in order to identify specific events like jets. Through the correlation between the quantities: thrust and recoil, calculated in minimum bias simulations of proton-proton collisions at 10 TeV, we show the sensitivity of the method to select specific topologies and high multiplicity. The presented results were obtained both at level generator and after reconstruction. It remains that with any kind of jet reconstruction algorithm one will confronted in general with overlapping jets. The present method determines areas where one does encounter special topologies of jets in an event. The aim is not to supplant the usual jet reconstruction algorithms, but rather to allow an easy selection of events allowing then the application of algorithms.Comment: 24 pages, ALICE Not

Start-up success of freelancers New microeconometric evidence from the German Socio-Economic Panel

If certain start-up characteristics will indicate a business success, knowing such characteristics could generate more successful start-ups and more efficient start-up counseling. Our study will contribut e to this by quantifying individual success determinants of freelance start-ups. The data base for the microeconometric analyses of the survival of the first three years is a revised German Socio-Economic Panel (SOEP) for 1992 until 2002, which allows to incorporate institutional, personal and family/household socio-economic variables. We describe and discuss the datawork to achieve compatible information over time within a revised GSOEP and present microeconometric rare events logit, logit and probit results. The start-up success measured as the probability to survive the first three years is first of all influenced by an active labour force participation with its acquired skills and working experiences just before the start-up period (rank 1), followed by a non-university degree as the highest general human capital indicator (rank 2), a general (non-linear) experience indicated by age (rank 3) and the business related background (rank 4) as the type of liberal profession in the group of the liberal medical professions and the liberal technical and scientific professions.start-up success, freelancers (liberal professions), German Socio-Economic Panel, rare events logit, logit, probit

Azimuthal Correlations in p-p collisions

We report the analysis of experimental azimuthal correlations measured by STAR in p-p collisions at $\sqrt{s_{NN}}$ = 200 GeV. We conclude that for a fit of data using Pythia event generator we need to include two values of $k_{T}$.Comment: 4 page, 3 figures. Prepared for X Mexican Workshop on Particles and Fields. Morelia Mich. Nov 7-12, 200

Effect of hard processes on momentum correlations

The effect of hard processes to be encountered in HBT studies at the Large Hadron Collider have been studied. A simple simulation has allowed us to generate momentum correlations involving jet particles as well as particles originating from the kinetic freeze out and to compare them to a simple theoretical model which has been developed. The first results on the effect of hard processes on the correlation function for the case of jet quenching are presented.Comment: 9 pages, 12 figures, talk presented at 2nd Warsaw Meeting on Particle Correlations and Resonances in Heavy Ion Collision