Nuclear Theory·nucl-th

Thursday·January 18, 2018

3 papers—2 primary·1 cross-listed

01
[Submitted on 16 Jan 2018]
Shell-model-like approach based on cranking covariant density functional theory: bandcrossing and shape evolution in $^{60}$ Fe
Z. Shi · Z. H. Zhang · Q. B. Chen · S. Q. Zhang · J. Meng
The shell-model-like approach is implemented to treat the cranking many-body Hamiltonian based on the covariant density functional theory including pairing correlations with exact particle number conservation. The self-consistency is achieved by iterating the single-particle occupation probabilities back to the densities and currents. As an example, the rotational structures observed in the neutron-rich nucleus $^{60}$ Fe are investigated and analyzed. Without introducing any \emph{ad hoc} parameters, the bandheads, the rotational spectra, and the relations between the angular momentum and rotational frequency for the positive parity band A, and negative parity bands B and C are well reproduced. The essential role of the pairing correlations is revealed. It is found that for band A, the bandcrossing is due to the change of the last two occupied neutrons from the $1 f_{5/2}$ signature partners to the $1 g_{9/2}$ signature partners. For the two negative parity signature partner bands B and C, the bandcrossings are due to the pseudo-crossing between the $1 f_{7/2, 5/2}$ and the $1 f_{5/2, 1/2}$ orbitals. Generally speaking, the deformation parameters $β$ for bands A, B, and C decrease with rotational frequency. For band A, the deformation jumps from $β \sim 0.19$ to $β \sim 0.29$ around the bandcrossing. In comparison with its signature partner band C, band B exhibits appreciable triaxial deformation.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1801.05503 [pdf]
PRC(2018)·29 citations
02
[Submitted on 17 Jan 2018]
Scaling properties of spectra in new exact solutions of rotating, multi-component fireball hydrodynamics
T. Csörgő🇭🇺 · G. Kasza🇭🇺
We describe fireballs that rehadronize from a perfect fluid of quark matter, characterized by the lattice QCD equation of state, to a chemically frozen, multi-component mixture, that contains various kinds of observable hadrons. For simplicity and clarity, we apply a non-relativistic approximation to describe the kinematics of this expansion. Unexpectedly, we identify a secondary explosion that may characterize fireball hydrodynamics at the QCD critical point. After rehadronization, the multi-component mixture of hadrons keeps on rotating and expanding together, similarly to a single component fluid. After kinetic freeze-out, the effective temperature $T_{i}$ of the single-particle spectra of hadron type $h_{i}$ is found to be a sum of the kinetic freeze-out temperature $T_{f}$ (that is independent of the hadron type $h_{i}$ ) and a term proportional to the mass $m_{i}$ of hadron type $h_{i}$ . The coefficient of proportionality to $m_{i}$ is also found to be independent of the hadron type $h_{i}$ but be dependent on the radial flow and vorticity of collective dynamics.
Comments:
12 pages, 2 figures, 6 tables, invited talk of G. Kasza at the 10th Bolyai-Gauss-Lobachevsky conference, Gyöngyös, Hungary, Aug. 21-25, 2017. Submitted for a publication to the MDPI journal Universe
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1801.05716 [pdf]
Universe(2018)·7 citations

Affiliations

first authorsco-authorsvia INSPIRE

Shell-model-like approach based on cranking covariant density functional theory: bandcrossing and shape evolution in 60Fe

Scaling properties of spectra in new exact solutions of rotating, multi-component fireball hydrodynamics

Affiliations

Shell-model-like approach based on cranking covariant density functional theory: bandcrossing and shape evolution in $^{60}$ Fe