相关论文: Shell-gap reduced level densities in $^{89,90}$Y

Excited states in $^{14}$O have been investigated both experimentally and theoretically. Experimentally, these states were produced via neutron-knockout reactions with a fast $^{15}$O beam and the invariant-mass technique was employed to…

We propose a new method to search for hypothetical scalar particles that have feeble interactions with Standard-Model particles. In the presence of massive bodies, these interactions produce a non-zero Yukawa-type scalar-field magnitude.…

We use quantum Monte Carlo methods in the framework of the interacting nuclear shell model to calculate the statistical properties of nuclei at finite temperature and/or excitation energies. With this approach we can carry out realistic…

The shell model within the $2s1d0g_{7/2}0h_{11/2}$ shell is applied to calculate nuclear structure properties of the even Z=52 - 62, N=82 isotones. The results are compared with experimental data and with the results of a quasiparticle…

We present a few simple observations on the occurrence of $\pi$-condensation in Nuclei, aimed at clarifying the nature of the $\pi$-condensation implied by the coherent nuclear $\pi$-N-$\Delta$ interaction, proposed in 1990 to explain the…

We show that spatial correlations in a stochastic large scale velocity field in an otherwise smooth intergalactic medium (homogeneous comoving density) superposed on the general Hubble flow, may cause a `line-like' structure in QSO spectra…

We point out a few remarkable properties of the $\gamma\gamma\to\gamma\gamma$ process at high energy. They should allow to search for effects of new particles and interactions. We give illustrations with threshold effects due to pairs of…

A novel approach to obtain the excitation spectrum of nuclei is presented as well as its proof-of-principle. The Monte Carlo Shell Model is extended so that the excitation spectrum can be calculated from its ground state with full of…

Fusion of very neutron rich nuclei may be important to determine the composition and heating of the crust of accreting neutron stars. We present an exploratory study of the effect of the neutron-gas environment on the structure of nuclei…

We calculate the spectrum of blast wave models of gamma-ray burst sources, for various assumptions about the magnetic field density and the relativistic particle acceleration efficiency. For a range of physically plausible models we find…

A model is presented to describe electromagnetically induced two-nucleon emission processes in a shell-model picture. Distortions in the outgoing nucleon waves are accounted for by performing a partial-wave expansion in a real mean-field…

Background: In the mass regions with an abnormal shell structure, the so-called ``island of inversion," the spin-parity of odd-mass nuclei provides quantitative insights into the shell evolution. However, the experimental determination of…

The quantum states of a system of particles in a finite spatial domain in general consist of a set of discrete energy eigenvalues; these are usually grouped into bunches of degenerate or close-lying levels, called shells. In fermionic…

A method to extract simultaneously level densities and $\gamma$-ray transmission coefficients has for the first time been tested on light nuclei utilizing the $^{28}$Si($^3$He,$\alpha\gamma)^{27}$Si and…

We report a combined experimental and theoretical investigation of near resonance light scattering from a high-density and ultracold atomic $^{87}$Rb gas. The atomic sample, having a peak density $\sim 5\cdot10^{13}$ atoms/cm$^{3}$,…

It has been shown that the large--scale correlation functions of the density field (and velocity divergence field) follow a specific hierarchy in the quasilinear regime and for Gaussian initial conditions (Bernardeau 1992). The exact…

We have made a thorough study of the low-energy behaviour of the $\gamma$-ray strength function within the framework of the shell model. We have performed large-scale calculations spanning isotopic and isotonic chains over several mass…

Neutron-capture reactions on very neutron-rich nuclei are essential for heavy-element nucleosynthesis through the rapid neutron-capture process, now shown to take place in neutron-star merger events. For these exotic nuclei, radiative…

$^{133}$Xe is an interesting case for plasma physics to explore nuclear excitation by electron capture, as the process can be studied using statistical properties of $^{133}$Xe. In this work we present results on $^{133}$Xe from the…

In-beam $\gamma$-ray spectroscopy was used to study excited states of the neutron-deficient nucleus $^{37}$K populated in fast-beam inelastic-scattering and proton-removal reactions at high-momentum loss. New $\gamma$-ray transitions and…