Nuclear surface effects in AuAu @ RHIC

Jet Tomography Studies in AuAu Collisions at RHIC Energies

Recent RHIC results on pion production in AuAu collision at √ s = 130 and 200 AGeV display a strong suppression effect at high pT . 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 t...

Coherent Photon-pomeron and Photon-photon Interactions in Ultra-peripheral Collisions at Rhic

Ultra-peripheral heavy ion collisions involve long range electromagnetic interactions at impact parameters larger than twice the nuclear radius, where no nucleonnucleon collisions occur. The first observation of coherent ρ production with and without accompanying nuclear breakup, AuAu→AuAuρ and AuAu→ AuAuρ respectively, and the observation of ee pair production AuAu→AuAuee are presented by the ...

How Nuclear Diffuseness Affects RHIC Data

The fact that nuclei have diffuse surfaces (rather than being simple spheres) has dramatic consequences on the interpretation of the RHIC heavy-ion data. The effect is quite small (but not negligible) for central collisions, but gets increasingly important with decreasing centrality. One may actually divide the collision zone into a central part (“core”), with expected high energy densities, an...

Diffractive J/ψ production in Ultraperipheral AuAu Collisions at RHIC

Proton-proton and deuteron-gold collisions at RHIC

We try to understand recent data on proton-proton and deuteron-gold collisions at RHIC, employing a modified parton model approach. 1 Interesting data from RHIC The nuclear modification factor R = (dNAA/d pt) / (Ncoll dNpp/d pt) shows interesting features: For AuAu, it is much smaller than one for central collisions, whereas for d-Au, it is bigger than one for central collisions. With decreasin...