Nuclear Many-Body Physics Where Structure And Reactions Meet
Naureen Ahsan, Alexander Volya
备注：
8 pages, 2 figures, presented at the 9th International Spring Seminar on Nuclear Physics, Vico Equense, Italy, 2007
发表信息：
Changing Facets of Nuclear Structure (Proceedings of the 9th International Spring Seminar on Nuclear Physics, Vico Equense, Italy, 20-24 May, 2007), 539-546
The path from understanding a simple reaction problem of scattering or tunneling to contemplating the quantum nuclear many-body system, where structure and continuum of reaction-states meet, overlap and coexist, is a complex and nontrivial one. In this presentation we discuss some of the intriguing aspects of this route.
Workshop on Chiral Forces in Low Energy Nuclear Physics - the LENPIC Meeting
我们介绍了2017年2月10日至11日在波兰克拉科夫雅盖隆大学举行的“低能核物理中的手征力-LENPIC会议”国际研讨会的小型会议记录。讲习班的重点是具有半局部正规化的新一代手征力及其在少核子和多核子系统中的应用。包括E.Epelbaum、K.Hebeler、R.Roth、H.Witala、A.Calci、P.Reinert、J. P. Vary、H.Kamada、I.Ciepal、H.Krebs、H.Le、K.Topolnicki、K.Vobig和Yu. Volkotrub的简短发言摘要。
We incorporate the coupled-channels optical model into the statistical Hauser-Feshbach nuclear reaction theory, where the scattering matrix is diagonalized by performing the Engelbrecht-Weidenmüller transformation. This technique has been implemented in the coupled-channels optical model code ECIS by J. Raynal, and we extend this method so that all the open channels in a nucleon-induced reaction on a deformed nucleus can be calculated consistently.
The nuclear transparency of the charged hadron produced in the inclusive $(e,e^\prime)$ reaction on the nucleus has been calculated using Glauber model for the nuclear reaction. The color transparency (CT) of the produced hadron and the short-range correlation (SRC) of the nucleons in the nucleus have been incorporated in the Glauber model to investigate their effects on the nuclear transparency of the hadron. The calculated nuclear transparencies for the proton and pion are compared with the data.
We present a brief overview of recent developments in ab initio calculations of nuclear scattering and reactions with a focus on applications of the no-core shell model with continuum method.
Nucleosynthesis is a complex process in astro-nuclear evolution. In this work, we construct a directed multi-layer nuclear reaction network using the substrate-product method from a thermonuclear reaction database, JINA REACLIB. The network contains four layers, namely $n$-, $p$-, $h$- and $r$, corresponding to the reaction types involved in neutrons, protons, $^4$He and the remainder, respectively. The degree values (i.e. numbers of reactions) for three layers of n-, p- and h- have a significant correlation with one another, and their topological structures exhibit a similar regularity. Howev…
We present recent results in theoretical studies on nuclear structure and reaction beyond mean field, using the adiabatic self-consistent collective coordinate method and its extension. We also present new results with the finite-temperature Hartree-Fock-Bogoliubov calculation with the three-dimensional-coordinate-space representation.
Calculations of the direct radiative capture reactions are made for the $^{48}$Ca$(n,γ)^{49}$Ca, $^7$Li$(n,γ)^8$Li and $^{12}$C$(p,γ)^{13}$N reactions with the Perey-Buck type nonlocal potentials using a potential model. Our results reproduce the experimental data reasonably well. From comparisons with results obtained by using local potentials, it is found that the cross sections of direct capture reactions may change by around 25\% due to the nonlcality of nuclear potentials.
We prove that the amplitudes for the (d,p), (d,pn) and (e,e'p) reactions determining the asymptotic behavior of the exact scattering wave functions in the corresponding channels are invariant under unitary correlation operators while the spectroscopic factors are not. Moreover, the exact reaction amplitudes are not parametrized in terms of the spectroscopic factors and cannot provide a tool to determine the spectroscopic factors.
Our understanding of the observed elemental abundance in the universe, stemming from nuclear reactions during the big bang or from nucleosynthesis within stellar environments, requires theoretical analyses based on multidimensional nucleosynthesis calculations involving hundreds of nuclei connected via thousands of nuclear processes. Up to recently, full nucleosynthesis network calculations remained computationally expensive and prohibitive. A recent publication by a Chinese group led by YuGang Ma [1] has proved that advanced computational algorithms developed in the last decade for the purpos…
We discuss equilibration times and isospin effect for various quantities in low-energy heavy-ion reactions. These include equilibration of mass, isospin, and total kinetic energy (TKE) in quasifission and deep-inelastic reactions. The calculations are performed using the time-dependent Hartree-Fock theory. The influence of shell effects on the equilibration times are also discussed in the context of theoretical and experimental results.
Using a theory of large amplitude collective motion, the adiabatic self-consistent collective coordinate method, we derive reaction path for the fusion process at sub-barrier energies. The collective Hamiltonian to describe the fusion process is constructed, based on the obtained reaction path and canonical variables. We study the reaction of N=Z stable nuclei, alpha+16O, 16O+16O, and alpha+12C. The results suggest that, after two nuclei touch, the reaction path is significantly deviated from the simple relative motion, which may affect the deep sub-barrier fusion cross section.
We present here a robust analytical model based on nuclear reaction theory for non-resonant fusion cross sections near Coulomb barrier. The astrophysical $S$-factors involving stable and neutron rich isotopes of C, O, Ne, Mg and Si for fusion reactions have been calculated in the centre of mass energy range of 2-30 MeV. The model is based on the tunneling through barrier arising out of nuclear, Coulomb and centrifugal potentials. Our formalism predicts precisely the suppression of $S$-factor at sub-barrier energies which are of astrophysical interest. The cross sections can be convoluted with …
It is shown, that the exponential decrease of the energy spectra of the fragments with growing its energy, which does not depend from the fragment type, targets, projectiles and projectile energies, and which sometimes accompanied slight oscillations, can be explained by the phenomenon of time resonances. These time resonances correspond to decay of intermediate excited nuclear composite system. For the first time, expressions for the decay rate and the probability of survival of such system as a function of time are obtained. Inclusive spectra for two real high-energy nuclear reactions are ca…
Transfer reactions are an important tool in nuclear astrophysics. These reactions allow us to identify states in nuclei and to find the corresponding energies, to determine if these states can contribute to astrophysical nuclear reactions and ultimately to determine the strength of that contribution. In this paper, the basic details of how transfer reactions may be used in nuclear astrophysics are set out along with some common pitfalls to avoid.
We present an introduction to ab initio nuclear theory with a focus on nuclear reactions. After a high-level overview of ab initio approaches in nuclear physics, we give a more detailed description of the no-core shell model technique equivalent to a large extent to configuration-interaction methods applied in quantum chemistry. We then introduce the no-core shell model with continuum approach that provides a quantum many-body description of nuclear reactions. After a brief review of nuclear reactions important for astrophysics, we present examples of results of ab initio calculations of radia…
Time-dependent Hartree--Fock (TDHF) method has been applied to various low-energy nuclear reactions, such as fusion, fission, and multinucleon transfer reactions. In this Mini Review, we summarize recent attempts to bridge a microscopic nuclear reaction theory, TDHF, and a macroscopic aspect of nuclear reactions through nucleus--nucleus potentials and energy dissipation from macroscopic degrees of freedom to microscopic ones obtained from TDHF in various colliding systems from light to heavy mass regions.
In this brief review we discuss the basic theoretical concepts used in the experimental studies of the most common cases of direct reactions such as (a) elastic scattering, (b) inelastic scattering, (c) Coulomb excitation, (d) transfer reactions and (e) breakup reactions.
