The study of nuclear excitations, particularly collective excitation modes such as the giant resonance (GR) and pygmy resonance (PR), can reveal important characteristics of the underlying nuclear structure. The PR is a fascinating excitation mode that is more prominent in nuclei with an excess of neutrons. This resonance is typically interpreted as a collective motion in which the neutron...
We conduct a numerical study of Stealth Dark Matter (SDM), a composite dark matter (DM) model in SU(4) gauge theory, using the method of lattice gauge theory. Utilizing the fastest supercomputers at Lawrence Livermore National Laboratory, we calculate the baryon-baryon scattering in SDM. In this talk, on behalf of the Lattice Strong Dynamics (LSD) collaboration, we discuss the recent progress...
In this presentation, we provides an improved understanding of the penetration probabilities(PPs) in nuclear reactions for light nuclei by rectifying the assumptions utilized in the conventional Gamow factor. The Gamow factor effectively represents PP in nuclear reactions based on two assumptions: particle energy lower than the Coulomb barrier, and the disregard of nuclear interaction...
The neutron-rich unstable nuclei near neutron magic numbers are relatively well studied, far from the stability lineup to the neutron magic number N = 82. However, for the neutron-rich nuclei to the south of 208Pb, there is limited knowledge of the excited states of these nuclei. This arises from the difficulty in producing these nuclei using conventional methods. Even for the known nuclei,...
The sensitivity studies of r-process nucleosynthesis performed in recent years [1-3] have pointed out that nuclear masses are of fundamental importance in r-process modeling. The results indicate that independently of the mass models and astrophysical scenarios used, the most sensitive mass regions are along and near the r-process path, particularly around N=50 and N=82 closed shells....
Although there is broad agreement that Type Ia Supernovae (SNe Ia) originate from thermonuclear explosions of carbon-oxygen white dwarf stars (WD), the details of the path towards explosion remain uncertain: the degeneracy of the binary system, mass, and chemical composition of the WD, and the explosion mechanism of the SNe Ia. Using the reaction rates in STARLIB [1] we probe the sensitivities...
In this Poster, we present a few examples of recent theoretical activities in IRIS.
After introducing the details of the deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc), we present our recent results on the bubble nuclei with shape coexistence in isotopes from Hf to Hg and alpha-decay half-lives of W to U. We predict several exotic isotopes that have both bubble configuration and shape coexistence. We also calculate alpha-decay half-lives in DRHBc and...
Transport models are microscopic model to describe heavy ion collisions. they let us study nuclear matter properties, which are important to understand such as neutron star. transport models categorized two type, BUU-like and QMD-like model, we have each, DJBUU and SQMD, which are developed for RAON experiments. In this study, we compare the result of simulation using each model.
Electron-capture (EC) rates play a key role in core-collapse and thermonuclear supernovae, the crust of accreting neutron stars in binary systems, and the final core evolution of intermediate mass stars. Charge-exchange reactions (CERs) at intermediate energies (~100 MeV) are crucial in extracting information for neutron-rich nuclei as the EC Q-values are positive for such nuclei. The...
Weak-interaction rates, including beta-decay and capture of electrons from the stellar plasma, are studied under various density and temperature conditions of astrophysical interest. The study focuses on different nuclear mass regions, such as neutron-deficient medium-mass waiting-point nuclei involved in the rp process, neutron-rich medium-mass isotopes involved in the r process, and pf-shell...
We report the identification of metastable isomeric states of Ac-228 at 6.28 keV, 6.67 keV, and 20.19 keV, with lifetimes of an order of 100 ns. These states were identified with NaI(Tl) crystal detectors of the COSINE-100 dark matter search experiment. The isomeric states are produced through the beta decay of Ra-228, a component of the Th-232 decay chain, with beta Q-values of 39.52 keV and...
