Comparison of Analytical Methods of E1 Strength Calculations in Middle and Heavy Nuclei

Simple analytical models for E1 strength function calculations of the $\gamma$-decay are investigated.Comment: Corrected version of the report for Eleventh Inter. Symp. on Capture Gamma-Ray Spectroscopy and Rel. Topics(Prague, 2-6 September, 2002); misprints are correcte

Shape of Dipole Radiative Strength Function for Asymmetric Nuclei

The semiclassical method for description of the radiative strength function is used for asymmetric nuclei with $N \ne Z$. The theory is based on the linearized Vlasov-Landau equations in two-component finite Fermi liquid. The dependence of the shape $E1$ strength on the coupling constant between proton and neutron subsystems was studied.Comment: Latex, 4 pages; 2 *.ps files with figures. Poster Report of Eleventh Inter. Symp. on Capture Gamma-Ray Spectroscopy and Rel. Topics, Prague, 2-6 September, 2002 (to be published in proceedings

Vibrational Enhancement of Nuclear Level Density within Response Function Method

Abstract. The main results are summarized on the development of the response function method for a description of the vibrational state effect on nuclear level density. The enhancement factor is calculated and compared within different approaches. The results of the RF approach are in the better agreement with the ones within the method of attenuated phonon occupation numbers. They also agree reasonably with results of a finite temperature extension of the interacting boson model

Verification of Models for Calculation of E1 Radiative Strength

Photoabsorption cross sections and gamma-decay strength function are calculated and compared with experimental data to test the existing models of dipole radiative strength functions (RSF) for the middle-weight and heavy atomic nuclei. Simplified version of the modified Lorentzian model are proposed. New tables of giant dipole resonance (GDR) parameters are given. It is shown that the phenomenological closed-form models with asymmetric shape can be used for overall estimates of the dipole RSF in the gamma -ray energy region up to about 20 MeV when GDR parameters are known or the GDR systematics can be adopted. Otherwise, the HFB-QRPA microscopic model and the semi-classical approach with moving surface appear to be more adequate methods to estimate the dipole photoabsorption RSF.Comment: 33 pages; 5 figures, 3 tables. Talk given at Workshop on Photon Strength Functions, Prague, Czech Republic, June 17-20, 200

Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal