[en] In this work we have measured the (e, 2n) and (e, 2p) cross sections and the (e + γ, 2n) (e + γ, 2 p) yields of ⁶³ Cu in the energy range 28-60 MeV. The cross sections were determined by residual activity, counting the gamma-rays emitted by the reactions products. The experimental results were analyzed by means of the virtual photon method in order to derive the photodisintegration cross sections. Our results for the 2n channel are in good agreement with results obtained at Livermore. From the analysis procedure we also obtained on the multipole composition of the photonuclear cross sections. On the 2n channel, E1 exhausts 12,4(11)% of the energy weighted sum, while isovector E2 exhausts 52(15)%. On the 2p channel obtained 1,03(8)% for E1 and an upper limit for the isovector E2 contribution of 0,58% of the EWSR. (author). 33 refs., 15 figs., 11 tabs p. 3

No abstract available

[en] I review various approaches to determining the transport properties of the quark gluon plasma from heavy ion data. First, I review efforts to extract the transport properties from small colliding systems such as CuCu. Then I discuss the application of viscous hydrodynamics to various parts of the heavy ion reaction. I emphasize the progress and the current difficulties in understanding the data with these methods

[en] We argue that RHIC data, in particular those on the anisotropic flow coefficients v₂ and v₄, suggest that the matter produced in the early stages of nucleus-nucleus collisions is incompletely thermalized. We interpret the parameter (1/S)(dN/dy), where S is the transverse area of the collision zone and dN/dy the multiplicity density, as an indicator of the number of collisions per particle at the time when elliptic flow is established, and hence as a measure of the degree of equilibration. This number serves as a control parameter which can be varied experimentally by changing the system size, the centrality or the beam energy. We provide predictions for Cu-Cu collisions at RHIC as well as for Pb-Pb collisions at the LHC

[en] Recent high-statistics Au+Au and Cu+Cu runs at RHIC have provided a wealth of new data that allow STAR to answer several outstanding questions regarding the nature of the hot, dense medium that is created in ultrarelativistic heavy-ion collisions. However, the new data also raise new questions that require further study. Here, we focus on a few qualitatively new results presented by STAR for the first time at Quark Matter '05

[en] Yields for J/ψ production in Cu+Cu collisions at √(s_NN)=200 GeV have been measured over the rapidity range |y|<2.2 and compared with results in p+p and Au+Au collisions at the same energy. The Cu+Cu data offer greatly improved precision over existing Au+Au data for J/ψ production in collisions with small to intermediate numbers of participants, in the range where the quark-gluon plasma transition threshold is predicted to lie. Cold nuclear matter estimates based on ad hoc fits to d+Au data describe the Cu+Cu data up to N_part∼50, corresponding to a Bjorken energy density of at least 1.5 GeV/fm³

[en] We present the first measurements of the pseudorapidity distribution of primary charged particles in Cu+Cu collisions as a function of collision centrality and energy, √(s_NN)=22.4, 62.4, and 200 GeV, over a wide range of pseudorapidity, using the PHOBOS detector. A comparison of Cu+Cu and Au+Au results shows that the total number of produced charged particles and the rough shape (height and width) of the pseudorapidity distributions are determined by the number of nucleon participants. More detailed studies reveal that a more precise matching of the shape of the Cu+Cu and Au+Au pseudorapidity distributions over the full range of pseudorapidity occurs for the same N_part/2A rather than the same N_part. In other words, it is the collision geometry rather than just the number of nucleon participants that drives the detailed shape of the pseudorapidity distribution and its centrality dependence at RHIC energies

[en] Neutral pion transverse momentum (p_T) spectra at midrapidity (|y| < or approx. 0.35) were measured in Cu+Cu collisions at √(s_NN)=22.4, 62.4, and 200 GeV. Relative to π⁰ yields in p+p collisions scaled by the number of inelastic nucleon-nucleon collisions (N_coll) the π⁰ yields for p_T(> or approx. 2 GeV/c in central Cu+Cu collisions are suppressed at 62.4 and 200 GeV whereas an enhancement is observed at 22.4 GeV. A comparison with a jet-quenching model suggests that final state parton energy loss dominates in central Cu+Cu collisions at 62.4 and 200 GeV, while the enhancement at 22.4 GeV is consistent with nuclear modifications in the initial state alone

No abstract available

[en] The pseudorapidity distributions of charged particles produced in Cu-Cu collisions over an energy range from 22.4 GeV to 200 GeV are investigated by using a multi-source ideal gas model which contains systematically the contributions of leading nucleons. It is shown that the calculated results are in agreement with the experimental data and the model is successful in the description of the pseudorapidity distribution of charged particles. The contributions of leading nucleons increase with the increasing impact parameter. The cylinder length (the longitudinal shift of the interacting system) in rapidity space increases with the increasing energy and does not depend on centrality at a given energy. (nuclear physics)