Relativistic mean field theory in finite nuclei

“Quantum” molecular dynamics—a dynamical microscopic n-body approach to investigate fragment formation and the nuclear equation of state in heavy ion collisions

The last decade has witnessed both quantitative and qualitative progresses in Shell Model studies, which have resulted in remarkable gains in our understanding of the structure of the nucleus. Indeed, it is now possible to diagonalize matrices in determinantal spaces of dimensionality up to 10^9 using the Lanczos tridiagonal construction, whose formal and numerical aspects we will analyze. Besides, many new approximation methods have been developed in order to overcome the dimensionality limitations. Furthermore, new effective nucleon-nucleon interactions have been constructed that contain both two and three-body contributions. The former are derived from realistic potentials (i.e., consistent with two nucleon data). The latter incorporate the pure monopole terms necessary to correct the bad saturation and shell-formation properties of the realistic two-body forces. This combination appears to solve a number of hitherto puzzling problems. In the present review we will concentrate on those results which illustrate the global features of the approach: the universality of the effective interaction and the capacity of the Shell Model to describe simultaneously all the manifestations of the nuclear dynamics either of single particle or collective nature. We will also treat in some detail the problems associated with rotational motion, the origin of quenching of the Gamow Teller transitions, the double beta-decays, the effect of isospin non conserving nuclear forces, and the specificities of the very neutron rich nuclei. Many other calculations--that appear to have ``merely'' spectroscopic interest--are touched upon briefly, although we are fully aware that much of the credibility of the Shell Model rests on them.

The shell model as a unified view of nuclear structure

Relativistic Hartree-Bogoliubov theory: static and dynamic aspects of exotic nuclear structure

Relativistic continuum Hartree Bogoliubov theory for ground-state properties of exotic nuclei

Interaction cross sections (${\ensuremath{\sigma}}_{I}$) for all known Li isotopes ($^{6}\mathrm{Li}$-$^{11}\mathrm{Li}$) and $^{7}\mathrm{Be}$, $^{9}\mathrm{Be}$, and $^{10}\mathrm{Be}$ on targets Be, C, and Al have been measured at 790 MeV/nucleon. Root mean square radii of these isotopes as well as He isotopes have been deduced from the ${\ensuremath{\sigma}}_{I}$ by a Glauber-type calculation. Appreciable differences of radii among isobars ($^{6}\mathrm{He}$-$^{6}\mathrm{Li}$, $^{8}\mathrm{He}$-$^{8}\mathrm{Li}$, and $^{9}\mathrm{Li}$-$^{9}\mathrm{Be}$) have been observed for the first time. The nucleus $^{11}\mathrm{Li}$ showed a remarkably large radius suggesting a large deformation or a long tail in the matter distribution.

/pdf/measurements-of-interaction-cross-sections-and-nuclear-radii-4n15y85k4c.pdf

Measurements of Interaction Cross-Sections and Nuclear Radii in the Light p Shell Region

https://escholarship.org/content/qt40n8x7p3/qt40n8x7p3.pdf?t=p0lm6b

Measurements of interaction cross sections and radii of He isotopes

The spectra of pions and light fragments at laboratory angles from 10/sup 0/ to 89/sup 0/ were measured in 0.8A GeV La+La collisions. Event multiplicity was also measured to select central collisions. For inclusive data, the slope of the pion spectrum at theta/sub c.m./ = 90/sup 0/ for La+La is as steep as that for Ar+KCl while the slope of the proton spectrum at theta/sub c.m./ = 90/sup 0/ becomes less steep with increasing mass number of the colliding nuclei. Furthermore, the ..pi../sup -/ yield is about half of the geometrical estimate while total nuclear charge yield agrees well. Since the yield ratio of ..pi../sup -/ to total nuclear charge at theta/sub c.m./ = 90/sup 0/ is significantly larger for high multiplicity events than for inclusive data, it appears that pion absorption by spectator nucleons is important. An azimuthal correlation of charged particle emission was also observed, which is consistent with collective flow of nuclear matter. The coalescence relation between protons and composite fragments holds for inclusive data in La+La collisions.

Production of pions and light fragments in 0.8A GeV La+La collisions

Measurements of the transverse momenta ([ital p][sub [ital T]]) of medium and heavy mass projectile fragments for a range of projectile nuclei ([sup 40]Ar, [sup 93]Nb, [sup 139]La, [sup 197]Au) have been carried out. It is found that the width of the transverse momentum distributions increases more rapidly with projectile and fragment mass than predicted by models based on nucleon momenta in the projectile nuclei. The distributions can be fit by including an additional transverse momentum, [ital p][sub [ital B]] (for Bounce). The extracted values of [ital p][sub [ital B]]/[ital A][sub [ital F]] increase with decreasing [ital A][sub [ital F]], and extrapolations to small [ital A][sub [ital F]] appear to be consistent with the mean values of reaction-plane-projected [ital p][sub [ital T]] per nucleon for light particle (e.g., nucleon) bounce-off.''

T. Kobayashi

Papers

Measurements of Interaction Cross-Sections and Nuclear Radii in the Light p Shell Region

Measurements of interaction cross sections and radii of He isotopes

Production of pions and light fragments in 0.8A GeV La+La collisions

Fragment mass dependence of p T at GeV per nucleon energies