In this talk, we will present a mechanism that provides self-interacting dark matter that can explain the small-scale structure problems such as the core cusp and too big to fail issues. We summarize simulations of self-interacting dark matter in models for galaxy formation and evolution. Then, constraints on the self-interacting dark matter with the cosmic microwave background and...
It has been known that there is an outstanding discrepancy between theoretical predictions and astronomical observations of primordial lithium abundances, so called cosmological lithium problem (CLP). From the point of view of nuclear physics, 7Be(n,p)7Li and 7Be(alpha,n)4He are the most important reactions which act to decrease 7Li in Big Bang nucleosynthesis (BBN). There was still lacked...
We will summarize the status of big-bang nucleosynthesis (BBN), which describes the production of the lightest nuclides during the first three minutes of cosmic time. We will emphasize the transformational influence of cosmic microwave background (CMB) experiments culminating today with Planck, which pin down the cosmic baryon density to exquisite precision. Standard BBN combines this with...
We investigate big bang nucleosynthesis (BBN) in Starobinsky gravity model with one additional term RabRab. This model includes various forms of cosmic evolution beyond the standard cosmic evolution based on the Einstein gravity model. Considering this interesting and rich forms of cosmic evolution, we calculate the primordial abundances of 4He, D, 3He, 7Li and 6Li during the BBN period and...
Fluorine is one of the most interesting elements in nuclear astrophysics, where the ${}^{19}\mathrm{F}(p,\alpha){}^{16}\mathrm{O}$ reaction is of crucial importance for Galactic ${}^{19}$F abundances and CNO cycle loss in first generation Population III stars. As a day-one campaign at the Jinping Underground Nuclear Astrophysics experimental facility, we report direct measurements of the...
In addition to the insights gained by studying the galactic evolution of chemical elements, short lived
radioisotopes contain additional information on astrophysical nucleosynthesis sites. Meteorites can
carry information about the nucleosynthetic conditions in the early Solar System using short lived
radioisotopes [1][2], while detections of live isotopes of cosmic origin in the deep sea...
We introduce a user-friendly detailed and modular GALactic Chemical Evolution Model, GalCEM, that tracks isotope masses as a function of time in a given galaxy. The list of tracked isotopes automatically adapts to the complete set provided by the input yields. The present iteration tracks 89 elements broken down into 456 isotopes. We include the following enrichment channels: massive stars...
We present the results of our study of the Luminosity Function of 521 LAEs having a Lya luminosity down to 10^39 erg s−1 with redshift in the range (2.9, 6.7) based on deep observations of 17 clusters obtained with MUSE at the ESO/ VLT. Taking advantage of the magnification effect, this unique data allows us to set strong constraints on the contribution of the LAE population to cosmic...
I will summarize the origin of elements using my Galactic chemical evolution model; only light elements such as hydrogen and helium were produced during the Big Bang. Heavier elements then helium are created inside stars. Alpha elements are mainly produced from core-collapse supernovae, while the majority of iron-peak elements are from Type Ia supernovae. Neutron-capture elements are produced...
We study the photodisintegration process triggered by the nonthermal electromagnetic Hawking radiation from primordial black holes (PBHs)
in the critical collapse model. The presence of a low-mass tail of critical collapse mass function could enhance energetic photon emissions from Hawking
radiation of PBHs. Nuclear photodisintegration rates are calculated with a nonthermal photon spectrum...
Nuclear reactions induced by neutrons play a key role in several astrophysical scenario like primordial nucleosynthesis, s and r process and so on. From an experimental point of view, their reaction cross sections and reaction rates at astrophysically relevant temperatures are usually a hard task to be measured directly. Nevertheless big efforts in the last decades have led to a better...
The RI beam accelerator facility called RAON is under construction in Korea. One of the experimental facilities called KoBRA is expected to carry out nuclear astrophysics and nuclear structure experiments in the early phase of RAON. Several experiments using both stable and RI beams of tens of MeV/nucleon are considered for understanding explosive nuclear synthesis in stellar sites such as...
First result from the R3 ring and scope for the r-process nuclei (tentative)
The study of the origins of heavy elements has been a critical issue for nuclear physics since short-lived nuclides far from the stability line are involved in synthesizing them. Notably, the rapid neutron capture process (r-process), which is considered to contribute to half of the nuclides heavier than iron, requires more knowledge of the nuclear properties of very neutron-rich...
Jinping Underground experiment for Nuclear Astrophysics (JUNA) takes advantage of the ultralow background of the CJPL. Commissioning of mA level high current accelerator based on an ECR source and BGO and 3He detectors finished in 2020. JUNA started experiments to directly study the many crucial reactions occurring at relevant stellar energies during the evolution stars. JUNA performed the...
The astrophysical rapid neutron capture (r-) process is thought to be responsible for the production of all of the observed thorium, uranium and plutonium in the cosmos. While nuclear data is continually being produced by radioactive beam facilities, many properties of the heaviest nuclei remain unmeasured. Thus, simulations of the r-process must rely on theory models that can be extrapolated....
There is a growing consensus in recent multi-messenger astronomy that the neutron star merger (NSM) as well as core collapse supernova (CCSN) and collapsar (which is very massive single star collapsing to a black hole) could be a possible site for the r-process nucleosynthesis. We will first discuss when and how these three astrophysical sites have contributed to enrichment of the r-process...
The astrophysical sites where 𝑟-process elements are synthesized remain mysterious: it is clear that neutron-star-mergers (kilonovae, KNe) contribute, and some classes of core-collapse supernovae (SNe) are also possible sources of at least the lighter 𝑟-process species. The discovery of 60Fe on the Earth and Moon implies that one or more astrophysical explosions have occurred near the Earth...
The light heavy elements between strontium and silver, can be synthesized in a primary process in either neutron- (weak r-process) or proton-rich (νp-process) neutrino-driven outflows of explosive environments [1]. Constraining the nuclear physics uncertainties, for example the (α,xn) reaction rates in the weak r-process [2,3], allows us to investigate the conditions that create the light...
Study of bulk properties of nuclear matter in general, and of the fission-fragment mass distribution (FFMD) in particular, is important for understanding of nuclear abundances in astrophysical processes. More specifically, the structure and composition of the FFMD is relevant for the description of abundances of elements within the 110$\le$A$\le$170 mass range in the neutron star merger...
Experimental study of symmetry energy
Nuclear weak rates relevant to the study of astrophysical processes in stars are evaluated with the use of shell-model Hamiltonians that prove to be successful in describing Gamow-Teller (GT) and spin-dipole (SD) strengths in nuclei. Electron-capture and β-decay rates in stellar environments induced by GT transitions in sd-shell and pf-shell are applied to study nuclear URCA processes in...
Quasi-periodic oscillations (QPOs) observed in giant flare from the magnetar, which is a strongly magnetized neutron star, are crucial information for extracting the neutron star properties. To theoretically explain the QPOs newly observed in GRB 200415A, we systematically examine the crustal torsional oscillations. Then, we find that the observed QPOs can be identified with several overtone...
Since the first direct observation of gravitational waves in September 2015, gravitational waves generated by binary black hole mergers and binary neutron star mergers have already been observed about 90 times. In particular, the binary neutron star merger in August 2017 was an extremely impactful astronomical phenomenon, as not only gravitational waves but also gamma-ray bursts were observed...
The properties of nuclear matter at extremely high densities and temperatures are still fraught with unknowns. Nevertheless, there are two environments in Nature for which the most dense forms of nuclear matter can be formed; these are during the collapse of the core of a massive star to form a supernova, and during the merger of two neutron stars to form a black hole. This talk will...
The radioactive isotope 10Be is among those that have been present when the solar system formed.
We review the production of this isotope in core-collapse supernovae via the ν-process considering
results from modern multi-dimensional simulations, as well as the sensitivity to nuclear reactions.
Recent nuclear experiments suggest that the cross-section of the most important destructive...
Triple-alpha reaction plays an important role in nucleosynthesis heavier than 12C, because no stable nuclei exist in mass number A=5 and A=8 [1,2]. Followed by 12C(alpha,gamma)16O, it controls the C/O ratio at the end of helium burning phase in stars, and it affects up to the nucleosynthesis in supernova explosion. In contrast to 12C(alpha,gamma)16O, the 3-alpha reaction is currently...
The fragments of one of the Chelyabinsk meteorite shower were investigated by methods of neutron physics. The source of thermal neutrons was the IBR-2 pulsed reactor (Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna). The neutron activation elemental analysis (NAA) of the meteorite was carried out for 10 major and 17 trace elements [1]. Comparison with the...
The calculation of the r-process abundance depends on either nuclear inputs or dynamical conditions of the astrophysical sites. In the present study, we study the sensitivity of the r-process abundance to the alpha-decay rates and fission barriers of heavy nuclei. The alpha-decay half-lives were estimated using semi-empirical models and taken from the newly updated database (NUBASE2020). The...
The isobaric single charge-exchange reactions, which are determined directly by the Fermi transition ($\Delta L = 0, \Delta S = 0, \Delta T = 1$) between the isobaric analog state (IAS) and the ground state of target, can be used as a tool to study bulk properties of nuclear matter and probed the neutron skin thickness in heavy nucleus. In this work, the ($^3$He,$t$)IAS reactions are studied...
Nuclear mass is one of the most important input for nucleosynthesis calculations at extreme conditions. However, the masses of exotic isotopes usually have large uncertainties since they are only predicted by various models due to the difficulties in the measurements that originate from their short life-times and low production cross sections. The precise mass of exotic nucleus may provide new...
The electrostatic accelerator (ESA) EG-5 occupies its unique niche as part of the complex of nuclear physics facilities of the FLNP JINR (Dubna, Russian Federation). The beams of high-energy particles (H+, He+, D+) produced using EG-5 have high energy stability (± 15 keV per 2 MeV), which makes it possible to conduct unique studies of the elemental composition of solids (meteorites), including...
Elements heavier than iron-group are produced by rapid and slow neutron-capture processes (r-process and s-process) in the universe. The site of the processes and history of the enrichment in the Milky Way Galaxy have been studied by spectroscopic observations of stars with different ages and population (Galactic disks, halo etc.). I will review the abundance studies of neutron-capture...
Signatures of stellar material affected by neutron-capture processes were not completely diluted in the early Solar System and are still found recorded in meteorites. These fingerprints of neutron captures range from radioactive isotopes produced by neutron captures, to stardust from asymptotic giant branch stars and core-collapse supernovae, as well as widespread highly diluted, but still...
Photon vortices caring orbital angular momentum (OAM) [1] with a wave function of Laguerre Gaussian (LG) wave or Bessel wave are one of the most interesting topics in various fields of physics. The interaction between a photon vortex and a material such nucleus may be different from that with standard photons because the photon vortex is the eigen-state of the z-component of the total angular...
Galactic feedback driven by massive stars and active galactic nuclei (AGNs) plays a fundamental role in regulating galaxy formation and evolution. In particular, intense starburst episodes could generate strong outflows able to suppress star formation (SF) by expelling large amount of dust and metals out of the galaxies, possibly enriching their circum (or even inter) galactic media. Galactic...
Accreting neutron stars show a broad range of observable phenomena that probe the properties of neutron stars. These phenomena are powered by nuclear reactions of proton-rich and neutron-rich unstable isotopes and include various types of X-ray bursts as well as the cooling neutron star crust in transiently accreting systems. Burst and crust observables are linked as the ashes of bursts...
During type I X-ray bursts, the rapid-proton capture (rp-) process has to pass through the NiCu cycles and ZnGa cycles before reaching the region above germanium and selenium isotopes that hydrogen burning occurs in. According to the sensitivity study by Cyburt et al. (2016), the $^{57}$Cu(p,$\gamma$)$^{58}$Zn reaction located in the NiCu cycles is the fifth important rp-reaction influencing...
The 18Ne(α,p)21Na reaction is one candidate of the breakout reactions from hot-CNO cycle, and it plays an important role in understanding the X-ray bursts and the nucleosynthesis in the rp-process. We investigated energy levels of the compound nucleus 22Mg by measuring the 18Ne(α,α)18Ne resonant scattering in inverse kinematics. The 18Ne rare isotope beam was produced at the CNS Radio-Isotope...
In this work, we re-assess the $^{65\!\!}$As(p,$\gamma$)$^{66\!}$Se reaction rates based on a set of proton thresholds of $^{66\!}$Se, $S_\mathrm{p}$($^{66\!}$Se), estimated from the experimental mirror nuclear masses, theoretical mirror displacement energies, and full $p\!f$-model space shell-model calculation. The mirror displacement energies with much reduced uncertainty of the...
The 26Al abundance holds a special role in present-day astrophysics, since it is a probe of active nucleosynthesis in the Galaxy and a valuable constraint of Galactic core-collapse supernovae rate. It is estimated through the detection of the 1809-keV γ-line of the daughter 26Mg and from the superabundance of 26Mg in comparison with the most abundant 24Mg isotope in meteorites. Accurate...
For the BRIKEN, RIBF207-ZDMRTOF collaboration
In the stellar rapid ($r$-) neutron-capture process nucleosynthesis, successive neutron-capture reactions under a large neutron-density environment push the matter toward the neutron-rich side until the beta-decay processes compete and heavier elements are formed. When neutron ceases, matters along the $r$-process path beta-decay to stability,...
The nuclear properties such as lifetimes and masses of the neutron-rich nuclei are important parameters to investigate the astrophysical rapid neutron capture process (r-process). However, the difficulty in the production of those neutron-rich nuclei, especially at the waiting points on the neutron closed shell $N = 126$ and beyond, makes their experimental studies difficult. Therefore, the...
The origin of nuclei heavier than iron is still an unsolved biggest question in nuclear astrophysics. The rapid and slow neutron-capture processes (r- and s-processes) are believed to be the origin of the neutron-rich heavy nuclei in the solar system. In addition to the two processes, recent spectroscopic observations of metal deficient asymptotic giant branch stars have raised the need for an...
Axion-like particles (ALPs) are a class of hypothetical bosons which feebly interact with ordinary matter. The hot plasma of stars and core-collapse supernovae is a possible laboratory to explore physics beyond the standard model including ALPs. Once produced in a supernova, some of the ALPs can be absorbed by the supernova matter and affect energy transfer. We recently calculated the ALP...
Strong magnetic fields could exist in the inner region of the explosive astrophysical site such as MHD-Jet SNe. The phase space of the electrons is quantized inside the magnetic field so that the weak interaction rates deviate from the field-free case. This talk focuses on the (anti)neutrinos absorption process. This process is essential since it determines the opacity of neutrino and the...
Systematic studies of core-collapse supernovae have been conducted based on hundreds of one-dimensional artificial models (O'Connor & Ott 2011,2013; Ugliano et al. 2013, Ertl et al. 2015) and two-dimensional self-consistent simulations (Nakamura et al. 2015;2019, Burrows & Vartanyan 2020). We have performed three-dimensional core-collapse simulations for 16 progenitor models covering ZAMS mass...
A large number of neutrinos emitted in a supernova explosion interacts with a dense plasma. The interaction between neutrinos and electrons changes the neutrino oscillation probability remarkably at the specific electron density, known as the Mikheyev–Smirnov–Wolfenstein (MSW) resonance effect. Previous studies for the neutrino process in core-collapsing supernova (CCSN) have well established...
In one of the most promising supernova theories, neutrino-heating mechanism, neutrinos carry the majority of the energy released during the gravitational collapse of massive stars. If neutrino flavors are converted fast in the cores, by depositing energy, they can rejuvenate stalled bounce shocks and provide the energy for supernova explosions. In this talk, I will present the results of our...
We report on a study of the reactions p+10,11B at low energy. The reactions are relevant in the field of astrophysics, nuclear physics, and also for applications. Studying these reactions provides additional input data for astrophysical models in particular towards astrophysical energies [1-2].
We have used the 5SDH-2 peletron accelerator at Hanoi University of Science to investigate the...
Since the first detected extrasolar X-ray source of Scorpius X-1 (aka Sco X-1) by Giacconi et al. in 1962, more than 7083 Type-I X-ray bursts generated by the respective 115 bursters have been observed. Reproducing the burst light curve is the key to accurately understanding thin-shell burning in Type-I X-ray bursts, nova outbursts, and Type-Ia supernovae, and to identifying important seed...
Direct observation of γ-ray emission from the decay of 18F ejected in classical nova outbursts remains a major focus of the nuclear astrophysics community. However, modeling the abundance of ejected 18F, and thus the predicted detectability distance of a γ-ray signal near 511 keV emitted from these transient thermonuclear episodes, is hampered by significant uncertainties in our knowledge of...
Neutron induced reactions on unstable nuclei play a significant role in the nucleosynthesis of the elements in the cosmos. Their interest range from the primordial processes occurred during the Big Bang Nucleosynthesis up to the “stellar cauldrons” where neutron capture reactions build up heavy elements. In the last years, several efforts have been made to investigate the possibility of...
The 42Ti(p,g)43V reaction rate plays an important role in the nucleosynthesis in type I X-ray bursts. In this work, the 42Ti(p,g)43V rate at temperatures relevant for X-ray bursts has been assessed. The spins, parities, and excitation energies of low-lying 43V levels were calculated with the OXBASH code, and were used, along with a new mass measurement of 43V, to obtain an updated...
Gamow-Teller (GT) strength distributions play a significant role in the neutrino-induced reactions supposed to be occurred in the supernova explosion. Most of the reactions are dominated by the GT transition among the other multipole transitions.
However, some nuclei show interesting behavior, so to say, GT peak in the lower energy region, due to the tensor force. We are going to discuss the...
Stellar evolution models or “The stellar evolution models and the critical nuclear reactions”
The 13C(a,n)16O reaction is the main neutron source for the slow-neutron-capture (s-) process in Asymptotic Giant Branch stars and for the intermediate (i-) process. Direct measurements at astrophysical energies in above-ground laboratories are hindered by the extremely small cross sections and vast cosmic-ray induced background. We performed the first consistent direct measurement in the...
12C+12C fusion reaction rate is essential for explosional phenomena, such as X-ray superbursts and type Ia supernovae, and the evolution of massive stars. However, it has significant uncertainties in low-energy regions. Experimentally, the cross sections are tiny due to the thick Coulomb barrier. Theoretically, treatments of the rearrangement in the fusion reactions, in which alpha and p decay...
The $^{12}$C/$^{16}$O abundance ratio is of prime importance to understand stellar evolution and energy generation in the universe. A tiny change in the abundance ratio can change an entire scenario of the stellar nucleosynthesis from carbon burning to the iron core in the last years of stellar life. Despite many experimental efforts in the last 50 years, none of the associated reactions like...
Nuclear data activities for astrophysics in Vietnam have been mainly approached from both theoretical and experimental studies of neutron-capture cross section, nuclear level scheme (NLS), nuclear level density (NLD) and radiative strength function (RSF) of gamma-ray emissions. Experimental studies have been performed based on the neutron-capture (n,gamma) reactions with different neutron...
The consistent Hartree-Fock calculation from the discrete to the continuum is a powerful tool for the microscopic analysis of nucleon-induced reactions in nuclear astrophysics. The cross sections of nucleon radiative capture reactions were analyzed within the bound-to-continuum potential model. Both single-particle bound and scattering states in the calculation of reduced matrix element of the...
Cluster formation is a universal phenomenon found in hierarchical layers of matter. The variation of clustering in the isotope chain toward the neutron drip-line is one of such interest. Recently, the negative correlation between the $\alpha$ cluster formation and neutron number in Sn isotopes has been reported by the experiment using the $(p,p\alpha)$ reactions showing the trend opposite to...
The neutron capture cross sections of W-186(n,g)W-187 reaction at 24 keV neutron energy were measured relative to the standard capture cross section of Au-197 by activation. The 24 keV filtered neutron beam at the Dalat nuclear research reactor has been used in the activation experiment. The measured cross section was normalized to obtain the Maxwellian averaged neutron capture cross sections...
We investigated the big-bang nucleosynthesis (BBN) on an expanding four-dimensional bubble nucleated in Kerr-AdS_5. This nucleation is caused by vacuum decay between two AdS vacua, and the bubble that separates the two vacua and surrounds a black hole is assumed to have a uniform tension. The black hole behaves like dark radiation on the bubble, and its “radiation density” depends on the mass...
The $\nu$-process nucleosynthesis in core-collapse supernovae is a sensitive probe of unknown neutrino mass hierarchy through the Mikheyev–Smirnov–Wolfenstein effect of neutrino flavor conversion in matter. The $\nu$-process depends on not only the neutrino-induced $\nu$-nucleus reactions but also many other nuclear reactions. Based on updated theoretical calculations and experimental result...
It is known that viruses and cosmic rays make a decisive contribution to the evolution of
biological species on Earth, participating in their transformation at the genetic level, largely
determining the processes of selection [1].
Nuclear reactions involving primary cosmic radiation and atmospheric ions can lead to the
formation of secondary neutrons. The density of the background neutron...
The $\beta$-decay properties of very neutron-rich nuclei, such as half-lives and $\beta$-delayed neutron emission probabilities, play an essential role in the astrophysical rapid neutron capture process ($r$-process), where the elements heavier than iron may be synthesized [1,2]. The investigation of those crucial properties has been one of the main objectives of the experimental programs at...
Type-I X-ray bursts are rapidly brightening phenomena induced by unstable hydrogen/helium burning near the surface of accreting neutron stars (NSs). During X-ray bursts, heavy proton-rich nuclei maximally up to the mass number A~107 are synthesized by a rapid-proton capture (rp) process, but how the nucleosynthesis proceeds depend on many model parameters such as the accretion rate, the...
Neutrino and antineutrino emission is dominant for the cooling process of neutron-stars (NSs).
Since neutrino emission rates depend on physical circumstances inside NSs, the study of NS cooling through neutrino emission gives important information for constraining internal NS structures
On the other hand, magnetic fields in NSs play important roles in the interpretation of many observed...
The goal of the Multi-Purpose Detector (MPD) [1] at the Nuclotron-based Ion Collider fAcility (NICA) [2] is to explore the QCD phase diagram of strongly interacting matter produced in nucleus-nucleus collisions at center-of-mass energy per nucleon pair $\sqrt{s_{NN}}$ = 4$-$11 GeV in the region of high net baryon chemical potential and moderate temperatures. The anisotropic flow is a key...
The radiative strength function (RSF), defined as the average electromagnetic transition probability per unit of $\gamma$-ray energy $E_\gamma$, is an important quantity to study the nuclear reaction properties such as emission rate, cross section, and nuclear astrophysical processes. We proposed a new method to describe the RSF within a microscopic approach, which is based on the damping of...
An unstable isotope Lu-176 decays to Hf-176 with a half-life of approximately 4×10^10 y. The Lu-176 could be used as a nuclear cosmochorometer for dating the nucleosynthesis event before the solar system formation. However, the half-lives measured with various nuclear experiments are inconsistent with each other. Furthermore, the half-lives evaluated from the Lu and Hf isotopic abundances in...
Recent models for evolved low-mass stars (with M <=3 Mo), undergoing the asymptotic giant branch (AGB) phase assume that magnetic flux-tube buoyancy drives the formation of 13C reservoirs in He-rich layers. We illustrate their crucial properties, showing how the low abundance of 13C generated below the convective envelope hampers the formation of primary 14N and the ensuing synthesis of...
Neutrino and astroparticle physics project BAIKAL-GVD is aiming at the identification of still unknown astrophysical sources of ultra-high energy (exceeding tens of TeV) neutrinos. The identification of sources will help to elucidate mechanisms of galaxies creation and evolution. Baikal-GVD - flagship experiment of JINR with its leading role in international collaboration. New experience in...