Nuclear Theory·nucl-th
11 papers—6 primary·5 cross-listed
Analytical expressions of the total number of levels for three and four fermions in a nuclear shell are provided. The formulas were derived using a combination of sum rules for coefficients of fractional parentage, and "unusual" identities, i.e. which do not contain the weighting factor involving and symbols.
S. Ayik · B. Yilmaz · O. Yilmaz · A. S. Umar
Employing a quantal diffusion description based on the stochastic mean-field (SMF) approach, we analyze the mass distribution of the primary fragments in the collisions of system at the bombarding energy ~MeV. This quantal approach provides a good description of the primary fragment distribution without any adjustable parameter, including the effects of shell structure.
Jun Xu · Arianna Carbone · Zhen Zhang · Che Ming Ko
We study if commonly used nucleon-nucleon effective interactions, obtained from fitting the properties of cold nuclear matter and of finite nuclei, can properly describe the hot dense nuclear matter produced in intermediate-energy heavy-ion collisions. We use two representative effective interactions, i.e., an improved isospin- and momentum-dependent interaction with its isovector part calibrated by the results from the \emph{ab initio} non-perturbative self-consistent Green's function (SCGF) approach with chiral forces, and a Skyme-type interaction fitted to the equation of state of cold nuclear matter from chiral effective many-body perturbation theory and the binding energy of finite nuclei. In the mean-field approximation, we evaluate the equation of state and the single-nucleon potential for nuclear matter at finite temperatures and compare them to those from the SCGF approach. We find that the improved isospin- and momentum-dependent interaction reproduces reasonably well the SCGF results due to its weaker momentum dependence of the mean-field potential than in the Skyrme-type interaction. Our study thus indicates that effective interactions with the correct momentum dependence of the mean-filed potential can properly describe the properties of hot dense nuclear matter and are thus suitable for use in transport models to study heavy-ion collisions at intermediate energies.
Tong Zhao🇨🇳 · Wei Zheng🇨🇳 · Fei Wang🇨🇳 · Cheng-Ming Li🇨🇳 · Yan Yan🇨🇳 · Yong-Feng Huang🇨🇳 · Hong-Shi Zong🇨🇳
As is pointed out in a recent work (Phys. Rev. Lett. 120, 222001), quark matter may not be strange. Inspired by this argument, we use a new self-consistent mean field approximation method to study the equation of state of cold dense matter within the framework of the two-flavor NJL model. Then the mass-radius relationship of two-flavor pure quark stars is studied. In the new self-consistent mean field approximation method we introduced, there is a free parameter , which reflects the weight of different interaction channels. In principal, should be determined by experiments rather than the self-consistent mean field approximation itself. In this paper, thus, the influence of the variation of on the critical chemical potential of chiral phase transition and the stiffness of the EOS are thoroughly explored. It is found that the stiffness of EOS can be increased greatly to support a two-solar-mass pure quark star when is greater than 0.95. This means that current theoretical calculations and astronomical observations cannot rule out the possibility of a two-flavor pure quark star.
A Poincaré-covariant continuum approach to the three valence-quark bound-state problem in quantum field theory is used to perform a detailed analysis of the nucleon's ground and first excited states: the so-called and . Such analysis predicts the presence of nonpointlike, fully-interacting quark-quark (diquark) correlations within them, being the isoscalar-scalar and isovector-pseudovector diquarks overwhelmingly dominant with similar relative strengths in both states. Moreover, the rest-frame wave functions of both states are largely -wave in nature and the first excited state in this channel has the appearance of a radial excitation of the ground state. All these features have numerous observable consequences, we show herein those related with the nucleon's elastic, Roper's elastic and nucleon-to-Roper transition electromagnetic form factors, for both charged and neutral channels.
N. Gavrielov · A. Leviatan · F. Iachello
We explore the situation of intertwined quantum phase transitions (IQPTs), for which a QPT involving a crossing of two configurations is accompanied by a shape evolution of each configuration with its own separate QPT. We demonstrate the relevance of IQPTs to the Zr isotopes, with such coexisting Type I and Type II QPTs, and ground state shapes changing from spherical to prolate axially deformed and finally to gamma-unstable. Evidence for this scenario is provided by a detailed comparison with experimental data, using a definite symmetry-based conceptual framework.
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