Tue·Jul 7, 2015Tuesday·July 7, 2015

1. 01*

   Comment on "New formulas for the (-2) moment of the photoabsorption cross section, \sigma_(-2)"

   Peter von Neumann-Cosel (Institut für Kernphysik, Technische Universität Darmstadt)🇩🇪

   Empirical formulas for the second inverse moment of the photoabsorption cross sections in nuclei are discussed in J. N. Orce, Phys. Rev. C 91, 064602 (2015). In this Comment I point out that the experimental values used are systematically too small in heavy nuclei by about 10% because of the neglection of the E1 strength below the neutron threshold. Furthermore, combining recently deduced values of the polarizability in heavy and total photoabsorption data in light nuclei it is demonstrated that the mass number dependence of \sigma_(-2) is sensitive to the ratio of volume and surface coefficients of the symmetry energy and parameters different to the ones chosen by Orce may be better suited.

   nucl-exPRC(2016)·9 citations
2. 02*

   Reaction-diffusion equation for quark-hadron transition in heavy-ion collisions

   Partha Bagchi🇮🇳 · Arpan Das🇮🇳 · Srikumar Sengupta🇮🇳 · Ajit M. Srivastava🇮🇳

   Reaction-diffusion equations with suitable boundary conditions have special propagating solutions which very closely resemble the moving interfaces in a first order transition. We show that the dynamics of chiral order parameter for chiral symmetry breaking transition in heavy-ion collisions, with dissipative dynamics, is governed by one such equation, specifically, the Newell-Whitehead equation. Further, required boundary conditions are automatically satisfied due to the geometry of the collision. The chiral transition is, therefore, completed by a propagating interface, exactly as for a first order transition, even though the transition actually is a crossover for relativistic heavy-ion collisions. Same thing also happens when we consider the initial confinement-deconfinement transition with Polyakov loop order parameter. The resulting equation, again with dissipative dynamics, can then be identified with the reaction-diffusion equation known as the Fitzhugh-Nagumo equation which is used in population genetics. We discuss the implications of these results for heavy-ion collisions. We also discuss possible extensions for the case of early universe.

   ↳ nucl-thcond-mat.stat-mechhep-phnlin.PS+1PRC(2015)·1 citation
3. 03*

   Halos in medium-heavy and heavy nuclei with covariant density functional theory in continuum

   Jie Meng🇨🇳 · Shan-Gui Zhou🇨🇳

   The covariant density functional theory with a few number of parameters has been widely used to describe the ground-state and excited-state properties for the nuclei all over the nuclear chart. In order to describe exotic properties of unstable nuclei, the contribution of the continuum and its coupling with bound states should be treated properly. In this Topical Review, the development of the covariant density functional theory in continuum will be introduced, including the relativistic continuum Hartree-Bogoliubov theory, the relativistic Hartree-Fock-Bogoliubov theory in continuum, and the deformed relativistic Hartree-Bogoliubov theory in continuum. Then the descriptions and predictions of the neutron halo phenomena in both spherical and deformed nuclei will be reviewed. The diffuseness of the nuclear potentials, nuclear shapes and density distributions, and the impact of the pairing correlations on nuclear size will be discussed.

   ↳ nucl-thnucl-exJ.Phys.G(2015)·205 citations
4. 04*

   Chiral geometry in multiple chiral doublet bands

   Hao Zhang · Qibo Chen🇨🇳

   The chiral geometry of the multiple chiral doublet bands with identical configuration is discussed for different triaxial deformation parameters $\gamma$ in the particle rotor model with $\pi h_{11/2}\otimes \nu h_{11/2}^{-1}$. The energy spectra, electromagnetic transition probabilities $B(M1)$ and $B(E2)$, angular momenta, and $K$-distributions are studied. It is demonstrated that the chirality still remains not only in the yrast and yrare bands, but also in the two higher excited bands when $\gamma$ deviates from $30^{\circ }$. The chiral geometry relies significantly on $\gamma$, and the chiral geometry of the two higher excited partner bands is not as good as that of the yrast and yrare doublet bands.

   ↳ nucl-thnucl-exCPC(2016)·14 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.