Narrow Results

We consider a semiclassical model of light nuclei, where the nucleus has a crystal-like shape and is built solely from α-particles. We analyze the role of linear configurations in this model, which correspond to super-deformed nuclei. The strong deformed shape for the doubly even nuclei from ¹²C to ²⁴Mg has been determined according to this model. The obtained results show a good agreement with the experimental data.

We present the investigation of the neutrino-induced strangeness associated production on nuclei in the relativistic plane wave impulse approximation (RPWIA) framework at the intermediate neutrino energies. In this study, the elementary hadronic weak amplitudes are embedded inside the nuclear medium for the description of the exclusive channels of neutrino–nucleus interactions. These amplitudes are extracted using a model-dependent evaluation of the hadronic vertex using the Born term approximation in which the application of the Cabibbo V–A theory and SU(3) symmetry are assumed to be valid. The nuclear effects are included via the bound state wave functions of the nucleon obtained from the relativistic mean field (RMF) models. Two kinematics settings are used to examine various distributions of the differential cross-section in the rest frame of the target nuclei. The numerical results are obtained for the neutrino-induced charged-current (CC) K⁺Λ-production on bound neutrons in 1s^1/2 and 1p^3/2 orbitals of ¹²C. The angular distributions are forward peaked under both kinematic settings, whereas under the quasifree setting, the cross-sections tend to mimic the missing momentum distribution of the bound nucleon inside the nucleus.

The quality of the description of masses of heavy nuclei by theoretical models is analyzed. Five of widely used macroscopic–microscopic models and one semi-empirical model are considered. All measured masses of nuclei with proton number Z≥82 and neutron number N≥126 are used in the analysis. Besides the accuracy of the description of the masses, the predictive power of the models in this description is also examined. It is obtained that the best accuracy is reached for the semi-empirical model (which is of a local type, specially adjusted to heavy nuclei). This model does not show, however, the best predictive power.

For the Riemannian space, built from the collective coordinates used within nuclear models, an additional interaction with the metric is investigated, using the collective equivalent to Einstein's curvature scalar. The coupling strength is determined using a fit with the AME2003 ground state masses. An extended finite-range droplet model including curvature is introduced, which generates significant improvements for light nuclei and nuclei in the trans-fermium region.

The reduced electric quadrupole transition rates have been calculated for states of the negative parity band in the ${}^{99}$Pd nucleus using semiclassical particle-rotor model calculations. The calculated transition rates are found to decrease with increasing spin states. The dynamic moment of inertia ${\Im }^{(2)}$ of the states above I = $23/2\hslash$ are found to be large. The spin ($\hslash$) versus frequency ($\hslash \omega$) plot obtained from the semiclassical model for the configuration $\pi {(g_{9/2})}^{-4}$ ⊗$\nu [h_{11/2}{(g_{7/2})}^2]$ is found to agree with the experimental data, which suggests a possible anti magnetic rotational character in the negative parity band.

The semiclassical particle-rotor model (SCM) has been used for the calculation of reduced electric quadrupole transition rates B(E2) for the $\nu h_{11/2}$ negative parity band in ${}^{101}$Ru. The B(E2) values are found to exhibit a decreasing behavior with increasing spin values in the range 27/2 $\hslash \le$ I $\le$ 47/2 $\hslash$. For the higher spin states, the experimental dynamic moment of inertia ${\Im }^{(2)}$ is also in the range of AMR bands. The calculation of spin ($\hslash$) versus frequency (MeV) for the $\pi {(g_{9/2})}^{-2}\otimes \nu [h_{11/2}{(g_{7/2})}^2]$ configuration with the core contribution of 2 $\hslash$ is found to be in good agreement with the experimental results and favors the possibility of AMR phenomenon in $\nu h_{11/2}$ negative parity band in ${}^{101}$Ru.

High-precision laser spectroscopy of atomic energy levels enables the measurement of nuclear properties. Sensitivity to these properties is particularly enhanced in muonic atoms which are bound systems of a muon and a nucleus. Exemplary is the measurement of the proton charge radius from muonic hydrogen performed by the CREMA collaboration which resulted in an order of magnitude more precise charge radius as extracted from other methods but at a variance of 7 standard deviations. Here, we summarize the role of muonic atoms for the extraction of nuclear charge radii, we present the status of the so called “proton charge radius puzzle”, and we sketch how muonic atoms can be used to infer also the magnetic nuclear radii, demonstrating again an interesting interplay between atomic and particle/nuclear physics.

A theoretical method based on energy-density-functional theory and quasiparticle-phonon model is applied for investigations of low-energy excitations of different multipolarities in stable and exotic nuclei. Of special interest is the possible relation of these modes to neutron or proton skins.

From investigations of low-energy dipole and quadrupole states new modes of excitations related to pygmy dipole and pygmy quadrupole resonances of neutron or proton character are identified. The astrophysical relevance of the pygmy resonances is discussed.