Electroproduction of hadrons on nuclei at GeV energies

We investigate coherence length effects and hadron attenuation in lepton scattering off nuclei in the kinematic regime of the HERMES experiment. The elementary electron-nucleon interaction is described within the event generator PYTHIA while a full coupled-channel treatment of the final state interactions is included by means of a BUU transport model. The results of our calculations are in good agreement with the experimentally measured transparency ratio of incoherent rho0 electroproduction off Nitrogen and the multiplicity ratio R_M^h for charged hadrons, pions, kaons, protons and anti-protons in deep inelastic scattering off Nitrogen and Krypton targets.Comment: 17 pages, 4 figures. Proceedings of 2nd Int. Conf. on Nuclear and Particle Physics with CEBAF at Jefferson Lab, Dubrovnik, 26-31 May 2003, to be published in Fizika

Nuclear shadowing and in-medium properties of the rho^0

We explain the early onset of shadowing in nuclear photoabsorption within a multiple scattering approach and discuss its relation to in-medium modifications of the rho^0.Comment: 4 pages, 2 figures, to appear in the proceedings of the 9th International Conference on the Structure of Baryons, Newport News, VA, USA, 3-8 Mar 200

Hadron attenuation by (pre)hadronic FSI at HERMES

We investigate hadron production in deep inelastic lepton-nucleus scattering in the kinematic regime of the HERMES experiment. Our calculations are carried out in the framework of a BUU transport model which contains the Lund event generators PYTHIA and FRITIOF for the simulation of high-energy elementary interactions. For the first time we consistently use the complete four-dimensional information of the Lund string break up vertices as input for our transport theoretical studies of (pre)hadronic final state interactions. We compare our results with experimental HERMES data on charged hadron attenuation.Comment: 6 pages, 2 figures, Presented at First Workshop on Quark-Hadron Duality and the Transition to pQCD, Frascati, Italy, 6-8 June 200

Hadron attenuation at HERMES by (pre)hadronic FSI

We investigate hadron formation in high energy electroproduction off complex nuclei in the framework of a BUU transport model. Our approach combines a quantum mechanical treatment of the photon's initial state interactions with a semi-classical coupled channel simulation of the (pre)hadronic final-state interactions (FSI). This allows us to study the hadron attenuation observed at HERMES and to get information on the space-time picture of hadron formation separately for $\pi^{\pm}$, $\pi^0$, $K^\pm$, $p$ and $\bar{p}$.Comment: 3 pages, 1 figure, Contributions to 8th International Workshop on Meson Production, Properties and Interaction (Meson 2004), Krakow, Poland, June 6-8 200

Hadronization in nuclear DIS and ultra-relativistic HIC

We present a transport theoretical analysis of hadron attenuation in deep inelastic lepton scattering (DIS) off complex nuclei in the kinematic regime of the HERMES experiment. The HERMES data indicate the presence of strong prehadronic final state interactions shortly after the elementary lepton-nucleon interaction. The contribution of such (pre-)hadronic final state interactions to the observed jet quenching in ultra-relaticistic heavy ion collisions (HIC) at RHIC is estimated under the assumption that a similar space-time picture for hadronization also holds in a hot hadronic medium. Our results show that an additional mechanism for jet quenching must be at work for most central collisions.Comment: 3 pages, 2 figures, to appear in the proceedings of the Particles and Nuclei International Conference (PANIC 05), Santa Fe, NM, USA, 24-28 Oct 200

Hadron formation in electron induced reactions at HERMES energies

We investigate meson electroproduction off complex nuclei in the kinematic regime of the HERMES experiment using a semi-classical transport model which is based on the Boltzmann-Uehling-Uhlenbeck (BUU) equation. We discuss coherence length and color transparency effects in exclusive rho^0 production as well as hadron formation and attenuation of charged pions, kaons, protons and anti-protons in deep inelastic lepton scattering off nuclei.Comment: 5 pages, 2 figures, to be published in the Proceedings of the "10th International Conference on Hadron Spectroscopy", Aschaffenburg, Germany, Aug. 31 - Sep. 6, 200

Elektrotvorba hadrona u jezgrama na GeVskim energijama

We investigate coherence-length effects and hadron attenuation in lepton scattering off nuclei in the kinematic regime of the HERMES experiment. The elementary electron-nucleon interaction is described within the event generator PYTHIA, while a full coupled-channel treatment of the final-state interactions is included by means of a BUU transport model. The results of our calculations are in good agreement with the experimentally measured transparency ratio of incoherent ρ 0 electroproduction off 14N and the multiplicity ratio Rh M for charged hadrons, pions, kaons, protons and anti-protons in deep inelastic scattering off 14N and 84Kr targets.Istražujemo učinke duljine koherencije i slabljenja hadrona u raspršenju leptona u jezgrama u kinematskin uvjetima mjerenja HERMES. Osnovno se međudjelovanje elektrona s nukleonom opisuje pomoću generatora događaja PYTHIA, dok je potpun opis međudjelovanja u konačnom stanju vezanim kanalima uključen transportnim modelom BUU. Ishodi naših računa su u dobrom skladu s mjerenim omjerom propusnosti nekoherentne elektrotvorbe ρ 0 u 14N i omjera višestrukosti Rh M za nabijene hadrone, pione, protone i antiprotone u duboko neelastičnom raspršenju u metama 14N i 84Kr