The excitation function of Au + Au in the framework of the (2+1)-fluid model

We present the excitation function of the reaction Au+Au in the frame work of the recently developed (2+1)-fluid model. In the (2+1)-fluid model, it is assumed that two baryonic fluids formed by the projectile and target nucleons produce a third hadronic fluid via inelastic nucleon-nucleon collisions. For this third fluid we use the equation of state of an interacting hadron gas obtained within the relativistic mean field model, including a first order phase transition. The dependence of the pion mean transverse momentum is investigated to observe the predicted plateau in the region of the phase transition of the hadronic matter to the quark-gluon plasma.     

Noisy scale-free networks

The impact of observational noise on the analysis of scale-free networks is studied. Various noise sources are modeled as random link removal, random link exchange and random link addition. Emphasis is on the resulting modifications for the node-degree distribution and for a functional ranking based on betweenness centrality. The implications for estimated gene-expressed networks for childhood acute lymphoblastic leukemia are discussed.     

Hartree-Fock-calculation of parity-violation in cesium

We present a relativistic Hartree-Fock calculation of the parity violatingE1-matrixelement of the 6s?7s transition in cesium. Our resultE1= ?8.4·10^?12 iea ₀ for sin² θ _w = 0.22 is in good agreement with the experimental value. We also give a general discussion of the consequences of a violation of discrete symmetries for the solutions of the Dirac equation.     

Coulomb distortions in heavy-ion reactions

In heavy-ion scattering the Coulomb potential deviates from the potential of two point charges since vibrations, rotations and giant resonances are excited in both projectile and target nuclei as a result of their mutual electrostatic forces. In this paper this effect is calculated using a classical model. The adiabatic and the dynamical solutions of the problem are compared and discussed.     

The collective 1+ state in triaxial nuclei

The energy spectra of the relative neutron-proton surface vibrations are discussed within the framework of the neutron-proton deformation model (NPD) in cases of deformed axial-symmetric and triaxial nuclei. It is shown that the energy spacing between the lowest 1⁺ states is of the order of the energy of the mass vibrations in axially symmetric nuclei and approaches values of rotational energies in the case of maximal asymmetry.     

Shape transitions and shape coexistence in the Ru and Hg chains

The General Collective Model (GCM) is revised and applied to the chain of^182–196Hg- and^96–108Ru-isotopes. Calculated energy spectra, absolute B(E2) values and Quadrupole moments are presented and compared to experiment. For many of these nuclei a coexistence of spherical and triaxial shapes was found. Additionally we investigated the shape transition within the Ru-chain from prolate (⁹⁶Ru) over spherical (⁹⁸Ru) to triaxial (A ≧100). The results are compared to microscopic and IBA calculations.     

Internal electron-positron pair production from electric monopole transitions

The yield curve of the reaction⁵⁶Fe(p,γ)⁵⁷Co has been measured over the energy rangeE _p =1,300–1,900 keV and the decay of nine resonances has been investigated. For twelve of the resonances the strengths have been determined. The angular distributions of the gamma rays have been recorded for resonances atE _p =1,599, 1,623, 1,643 and 1,649 keV, giving spin-parity assignmentsJ ^π=3/2^? for all four resonances. The resonances atE _p =1,623, 1,643 and 1,649 keV have been identified as the split analogue resonances of the 367 (J ^π=3/2^?) states in⁵⁷Fe. TheM1 transition strengths to the corresponding antianalogue states have been measured and compared with theoretical predictions.