Nuclear Astrophysics is low energy reaction physics – with stable and radioactive nuclei. The goal of the field is to understand critical reaction cross sections at stellar energies which are typically not directly accessible by experiment. The reaction rates therefore depend on reliable extrapolation of the reaction rates towards the stellar energy regime. A number of near threshold effects...
Neutron production for the slow neutron capture process ($s$-process) is dominated by $(\alpha,n)$ reactions on light nuclei during stellar helium burning. Chief amount these is the $^{13}$C$(\alpha,n)^{16}$O reaction, whose low energy cross section is enhanced by the presence of broad resonances and subthreshold states. Experimental measurements have been reported recently at both the LUNA...
The efficiency of the weak s-process in low metallicity rotating massive stars depends strongly on the ratio of the reaction rates of the two competing $^{17}$O($\alpha$,n)$^{20}$Ne and $^{17}$O($\alpha$,$\gamma$)$^{21}$Ne reactions, which impacts the poisoning effect of $^{16}$O that consumes the neutrons released by the $^{22}$Ne($\alpha$,n)$^{25}$Mg reaction [1] .
However, the reaction...
About half of the solar abundance of elements heavier than iron are made by the slow neutron capture process (s-process) occurring in low and intermediate-mass asymptotic giant branch (AGB) stars. Elements are mixed from the core to the surface and then expelled into the interstellar medium through strong stellar winds. In comparison to the rapid neutron capture process, modelling the...
About half of the elements heavier than iron are produced in rather quite stellar environments during long exposures of seed material with neutrons. The interplay between neutron captures and beta-decays enables the production of all elements between iron and bismuth. This process is called slow neutron capture process, or s process.
Radioactive isotopes on the s-process path can act as...
Theoretical stellar nucleosynthesis calculations allow direct comparison between predicted stellar abundances and observations, as well as interpretation of the isotope composition of meteoritic components. Our computational method for calculating predictions for stellar abundances from AGB stars involves two steps: first, the evolution of the stellar structure is calculated by the Stromlo...
The Jinping Underground experiment for Nuclear Astrophysics (JUNA) has leveraged the ultralow background of the CJPL to conduct experiments aimed at directly studying crucial reactions occurring at relevant stellar energies during the evolution of stars. In 2020, JUNA successfully commissioned an mA level high current accelerator based on an ECR source, as well as BGO and $^3$He detectors....
In nuclear astrophysics, a crucial aspect is understanding the thermonuclear reactions that power the stars and lead to the synthesis of chemical elements. At astrophysical energies, the cross section of nuclear processes is significantly reduced by the Coulomb barrier, making direct measurements challenging. In addition, the low value of cross sections often hinders their measurement on...
Direct measurements of the cross sections for the radiative capture reactions ${}^{12,13}\mathrm{C}(\mathrm{p},\gamma){}^{13,14}\mathrm{N}$ at energies of astrophysical interest are challenging, due to the rapidly falling cross sections towards lower energies, and for the absence of narrow resonances at low proton energies required for target characterization. The two reactions have been...
The reactions 22Ne(a,n)25Mg and 22Ne(a,g)26Mg are of high importance for the formation of heavy elements in the weak s process, main s process branchings and strongly influence the Mg isotopic ratios that we can directly observe in stellar atmospheres. For an accurate astrophysical modeling, both reaction cross sections need to be known at energies far below the Coulomb barrier, where direct...
The interplay and correlation between the $^{22}$Ne$(\alpha,\gamma)^{26}$Mg and the competing $^{22}$Ne$(\alpha,n)^{25}$Mg reaction determines the efficiency of the $^{22}$Ne$(\alpha,n)^{25}$Mg reaction as a neutron source for the weak $s$-process. In both cases, the reaction rates are dominated by the strength of the $\alpha$ cluster resonance at 830 keV. This plays a particularly important...
The $^{13}$C($\alpha$,n)$^{16}$O 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...
In recent years, new astronomical observations have revealed abundance patterns that cannot be explained by the classic nucleosynthesis picture. A description of the synthesis of heavy elements using only the s, r and p processes is not adequate anymore and for this reason new scenarios had to be proposed. In this talk I will focus on neutron-capture processes that involve exotic nuclei,...
Observations of astrophysical phenomena, such as the luminosity of X-ray bursts and the abundance pattern of stars, can be explained by nuclear reactions occurring in the stars. It is well known that the nuclear properties of isotopes involved in the nuclear reactions have a direct impact on stellar evolution, such as energy generation, the nucleosynthesis path, and final abundance...
Albeit recent development of dynamical approaches to the nuclear fission phenomena has been significantly improving our understanding of this complex nuclear reaction mechanism, conventional fission models in the statistical Hauser-Feshbach theory remain the extremely simplified fission barrier model with the WKB approximation. Due to the inherent deficiencies in calculating nuclear fission...
To constrain the nu-p process, we studied the $^{56}$Ni(n,p) reaction by directly measuring the cross section on the radioactive $^{56}$Ni (a half-life of 6 days) at Los Alamos Neutron Science Center. This reaction has been identified as one of critical reactions for understanding the heavy element production in core-collapse supernovae. The radioactive $^{56}$Ni was produced by irradiating...
A neutron star can accrete hydrogen-rich material from a low-mass binary companion star. This can lead to periodic thermonuclear runaways, which manifests as a Type I X-ray bursts detected by space-based telescopes. Sensitivity studies have shown that ${}^{15}\text{O}(\alpha, \gamma){}^{19}\text{Ne}$ carries one of the most important reaction rate uncertainties affecting the modeling of the...
We investigated $^{10}$Be production mechanism in the neutrino-process in the core collapsing supernova (CCSN) by including recent updated nuclear reactions relevant to dominant production and destruction of $^{10}$Be. They involve production reactions by neutrinos $^{12}$C and $^{16}$O and other production reactions $^{10}$B(n,p)$^{10}$Be, $^{11}$Be($\gamma$, n)$^{10}$Be. Inverse reactions of...
Globular clusters are key grounds for models of stellar evolution and early stages of the formation of galaxies. Abundance anomalies observed in the globular cluster NGC 2419, such as the enhancement of potassium and depletion of magnesium [1] can be explained in terms of an earlier generation of stars polluting the presently observed stars [2]. However, the nature and the properties of the...
Asymptotic giant branch (AGB) stars are a late evolutionary phase of low- and intermediate-mass star. They are typified by rapid mass loss through a stellar wind rich in molecular diversity, which is also a key site of dust formation in the universe. Their stellar winds provide a unique opportunity to study the isotopic ratios of various key atomic species that form molecules and whose...
Soft gamma ray lines from radioactive decay
of 26Al and 60Fe as well as annihilation of positrons have been
observed from the Milky Way. The respective emission contains information
about the ejecta of supernovae, massive-star winds and possibly winds related to neutron stars and
black holes. The distinct spatial structure of the different lines allows
to trace the flow of the ejecta...
The most metal-poor low-mass stars formed in the very Early Universe, at about 300 Myr after the Big Bang, are still observable today in the Galactic Halo. These stars hold crucial information of the early epochs of the Universe, such as the properties of the first stars and supernovae and the early chemical evolution of the Universe, and the formation of low-mass stars in the Early Universe....
Very metal-poor stars that have [Fe/H]$< -2$ and are enhanced in C relative to Fe ([C/Fe]$>0.7$) but have low enhancement of heavy elements ([Ba/Fe]$<0$) are known as carbon-enhanced metal-poor-no (CEMP-no) stars. These stars are thought to be produced from the interstellar medium (ISM) polluted by the supernova (SN) ejecta of the very first generation (Pop III) massive stars. Although...
The 12C/13C isotopic ratio is an important diagnostic tool in astrophysics, providing insights into the formation and evolution of stars and galaxies. In this talk, we will discuss the measurement of this ratio using data from the ESPRESSO instrument, which is one of the most powerful spectrographs in the world.
We will focus on the information obtained from the oldest stars in the Milky...
Half of the heavy elements are produced in r-process nucleosynthesis, which is exclusively responsible for actinide production, such as Pu-244 (t$_{1/2}$=81 Myr). The r-process requires an explosive scenario but is far from being fully understood; in particular, its sites and history.
The solar system moves through the interstellar medium (ISM) and collects interstellar dust particles that...
Radioactive parts of nucleosynthesis ejecta transmit the results of nucleosynthesis in stars and supernovae from the current and most recent stellar generations. INTEGRAL observations have measured emission from the long-lived (My) isotopes 26Al and 60Fe over the past 20 years. It is a challenge to decipher these signals in the context of other patchy knowledge and models about these recent...
In this biased review talk I will first summarise a modelling workflow (the “pipeline”) that connects rapid binary evolution progenitor models to supernova observables, via supernova explosion and nucleosynthesis simulations. I will then highlight how we can use model specific nucleosynthetic signatures of different explosion models to make inferences about what kind of white dwarfs explode as...
Type I X-ray bursts (XRBs) are thermonuclear explosions in the H/He-rich envelopes accreted onto neutron stars in close binary systems. These events constitute the most frequent type of thermonuclear stellar explosion in our Galaxy (the third, in terms of total energy output after novae and supernovae). To date, most of the efforts undertaken in the modeling of XRBs have relied on...
Simulations of explosive nucleosynthesis in novae predict the production of the radioisotope $^{22}$Na. Its half-life of 2.6 yr makes it a very interesting astronomical observable by allowing space and time correlations with the astrophysical object. Its $\gamma$-ray line at 1.275 MeV has not been observed yet by the $\gamma$-ray space observatories. This radioisotope should bring constraints...
The precise origin of Type Ia supernovae (SNe Ia) is unknown despite their value to numerous areas in astronomy. While it is a long-standing consensus that they arise from an explosion of a C/O white dwarf, the exact progenitor configurations and explosion mechanisms that lead to a SN Ia are still debated. One popular theory is the double detonation in which a helium layer, accreted from a...
The elastic $\alpha$-$^{12}$C scattering at low energies for $l=0,1,2,3,4,5,6$ is studied in effective field theory. We discuss the construction of the $S$ matrices of elastic $\alpha$-$^{12}$C scattering in terms of the amplitudes of sub-threshold bound and resonant states of $^{16}$O, which are calculated from the effective Lagrangian. The parameters appearing in the $S$ matrices are fitted...
The properties of neutron-rich nuclear systems are largely determined by the density dependence of the nuclear symmetry energy. Experiments aiming to measure the neutron skin thickness [1,2] and astronomical observations of neutron stars and gravitational waves [3,4] offer valuable information on the symmetry energy at sub- and supra-saturation densities, respectively.
The...
Type Ia supernovae are extremely bright thermonuclear events and have been very well studied by numerous observations. However, there remain many open questions about the progenitor system for these explosive events. In the single-degenerate progenitor model, in which a white dwarf accretes mass from a stellar companion, a phase of simmering occurs where carbon burning drives core convection...
The origin and evolution of heavy elements in nature are not yet fully understood. THis talk will overview the current status of models for both the formation of both r-process and nu-p-process elements. We summarize recent state-of the art developments of supernova and binary neutron star evolution in the context of both the r-process and p-process nucleosynthesis. In particular, we ...
A group of reactions involving neon isotopes have been studied at the Laboratory for Underground Nuclear Astrophysics (LUNA) using the intense proton beam delivered by the LUNA 400 kV accelerator and a windowless differential-pumping gas target.
For years the $\mathrm{^{22}Ne(p, \gamma)^{23}Na}$ reaction was the most uncertain reaction in the NeNa cycle of hydrogen burning. LUNA was able to...
PANDORA (Plasmas for Astrophysics, Nuclear Decay Observations and Radiation for Archaeometry) is an upcoming facility at INFN - LNS aiming to use an electron cyclotron resonance ion source (ECRIS) as a compact magnetoplasma to measure in-plasma $\beta$-decay lifetimes of radioisotopes. Decay rates are susceptible to changes in atomic configuration of the parent and daughter systems and are...
One of the goals of nuclear astrophysics is to understand the various astrophysical events occurring in the cosmos.
The most common stellar explosions observed in our galaxy are Type I X-ray bursts (XRB1).
The isotopic abundances obtained from the astrophysical models of XRB1 depend strongly on a number of nuclear reaction rates, occurring both on the surface and inside the crust by the...
With LIGO-Virgo-KAGRA in its fourth observing run, a new opportunity to search for electromagnetic counterparts of compact object mergers is also upon us. The light curves and spectra from the first "kilonova" associated with a binary neutron star binary (NSM) suggests that these sites are hosts of the rapid neutron capture ("r") process. However, it is unknown just how robust elemental...
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...
Theoretical predictions and past experiments on highly ionized atoms have shown that the β-decay lifetime can be modified even by several order of magnitudes relative to the value observed in neutral atoms due to the opening of a new decay channel called bound-state β-decay [1,2]. The effect of this variation is particularly relevant for those nuclei placed at the branching point of the...
We report that the standard evolution of radiation-dominated era (RDE) universe $a \propto t^{1/2}$ is a sufficient condition for solving a sixth order gravitational field equation derived from the Lagrangian containing $B R^{ab}R_{ab} + C R R^{;c}_{\phantom{;c}c}$ as well as a polynomial $f(R)$ for a spatially flat radiation FLRW universe. By virtue of the similarity between $R^{ab}R_{ab}$...
Triple-$\alpha$ reaction plays a significant role in nucleosynthesis heavier than $^{12}$C and concomitant stellar evolution [1]. The reaction rates of this reaction at the helium-burning temperatures, $T_9 > 0.1$, are dominated by the sequential process via two narrow resonances: $\alpha+\alpha\rightarrow ^8$Be(0$^+_1$), $^8$Be+$\alpha \rightarrow ^{12}$C(0$^+_2$: $E=0.379$ MeV) [2,3], and...
The 15O(α, γ)19Ne and 18F(p, α)15O reaction rates at stellar temperatures have significant impacts on the dynamics in x-ray bursts, novae explosions, and heavy element synthesis. Due to its importance, the nuclear structure of the compound nucleus 19Ne, which determines the reaction rate, has been widely investigated. Collecting the available data from experimental measurements, Nesaraja et...
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...
We analyze the behavior of a nucleus as it moves through a superfluid neutron medium located in the inner crust of a neutron star. One important aspect of studying the behavior of nuclei in neutron stars immersed in superfluid neutrons is understanding how their effective mass is affected by interactions with the surrounding particles. To study it, we utilized the Time-Dependent...
Strong magnetic fields such as MHD-Jet SNe could exist in the inner region of the explosive astrophysical site. 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 the neutrino and the...
The study of the $^{26}$Si($\alpha$,$p$)$^{29}$P reaction rate is essential for understanding X-ray burst phenomena. It is believed that the heavy elements up to the Sn-Sb-Te region can be synthesized during the burst. Since 26Si is considered to be a waiting point during the burst, the $^{26}$Si($\alpha$,$p$)$^{29}$P reaction rate is believed to be one of the most significant reactions that...
When stars approach the red giant branch, a deep convective envelope develops and the products of the CNO cycle appear at the stellar surface. In particular, the $\rm ^{17}O$ is enhanced in RGB and AGB stars. Spectroscopic analyses of O isotopic ratios of these stars provide a powerful tool to investigate the efficiency of deep mixing processes, such as those powered by convective overshoot,...
We have studied the structure of the proton-rich 14O nucleus by performing the 10C + α elastic scattering measurement at the CRIB facility (CNS, the university of Tokyo). Recently, the cluster nature for some resonances was identified in the mirror nucleus 14C via the 10Be + α reaction (1). A preliminary Resonating Group Method (RGM) calculation has suggested that also the 10C + α system may...
Axion-like particles (ALPs) are a class of hypothetical pseudoscalar particles which feebly interact with ordinary matter. The hot plasma in core-collapse supernovae is a possible laboratory to explore physics beyond the standard model including ALPs. Once produced in a supernova, a part of the ALPs can be absorbed by the supernova matter and affect energy transfer. We recently developed...
$^{163}$Ho has been considered as a suitable candidate for the capture of relic antineutrinos. However, the detection of the relic antineutrino using $^{163}$Ho is extremely challenging with current techniques. Therefore, we have searched for new targets for relic antineutrino detections through the resonant capture on nuclides undergoing electron capture. We have investigated nuclear and...
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...
In 2017, the electromagnetic counterpart AT2017gfo to the binary neutron star merger GW170817 was observed by all major telescopes on Earth. While it was immediately clear that the transient following the merger event, is powered by the radioactive decay of r-process nuclei, only few tentative identifications of light r-process elements have been made so far. One of the major limitations for...
The Rare isotope Accelerator complex for ON-line experiments (RAON) is a heavy ion accelerator facility that provides both stable and rare isotope (RI) beams for basic and applied science research. The in-flight fragment (IF) separator of RAON, the main device for producing RI beams, is under development. In order to efficiently produce RI beams by using in-flight fission of uranium beams as...
The cosmological lithium problem has been known as the outstanding discrepancy of primordial lithium abundances between observations and theoretical predictions. We have measured key nuclear reactions which act to reduce $^7$Li during the big bang nucleosynthesis (BBN), namely, $^7$Be$(n,p)^7$Li and $^7$Be$(n,α)^4$He, by means of the Trojan Horse method [1].
We also performed $R$-matrix...
The discovery of GW170817 has significantly advanced our understanding of the high-density equation of state. In this talk, I will showcase our recent findings, which involve constraining the hadron-quark phase transition using both the existing GW170817 data and future GW observations. The discussion will encompass the constraints derived from both quasi-equilibrium tides and dynamic tides.
Developments of the rare beam acceleration have opened new opportunities for study of mirror resonance reactions. Namely, comparison of the results of the mirror resonance reactions gives the opportunity to understand nuclear structure deeper.
$\quad$ Understanding the nuclear structure of $^{19}F$ and $^{19}Ne$ is crucial in comprehending the clustering structure around mass $A=20$. ...
Asymptotic giant branch (AGB) stars are a key site of element synthesis in galaxies. As low-mass AGB stars evolve, they undergo internal helium-burning shell flashes, or thermal pulses. These thermal pulses temporarily extinguish the hydrogen-burning shell, allowing the convective envelope of the star to move into the intershell region, mixing products of helium-burning to the surface,...
The radiative proton capture reaction of $^{15}\mathrm{N}(p, \gamma)^{16}\mathrm{O}$ is one of the thermonuclear reactions in the carbon-nitrogen-oxygen (CNO) cycle. This process provides a link between the type-I (CN) cycle and type-II (NO) cycle so that the $^{16}\mathrm{O}$ nucleus can be produced and the further types of the cycle start. We investigated the $^{15}\mathrm{N}(p,...
Our study links cosmic evolutions in the extended Starobinsky model (eSM), Big Bang Nucleosynthesis (BBN), and early universe chemistry. We demonstrate standard and oscillating cosmic evolutions and discuss BBN constraints. By connecting BBN abundances to the early universe chemistry, we identify the formation of intriguing and critical molecular structures. These findings underscore the...
14O(α,p)17F is one of the important reactions that strongly affects the light curves of Type Ⅰ X-ray burst models [1]. The reaction rate is known to determine the break-out path from the hot CNO cycle to the rp-process at sufficiently high temperatures (T9 > 0.5) [2]. However, its large uncertainty due to the lack of experimental measurements causes difficulties in the precise demonstration of...
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....
Neutron star mergers (NSMs) are the first verified sites of rapid neutron capture (r-process) nucleosynthesis, and could emit gamma rays from the radioactive isotopes synthesized in the neutron-rich ejecta. These MeV gamma rays may provide a unique and direct probe of the NSM environment as well as insight into the nature of the r process, just as observed gammas from the 56Ni radioactive...
Neutrino and antineutrino emissions are 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 $^{12}$C+$^{12}$C fusion reaction plays an important role in various astrophysical models, such as type Ia supernova, superburst, and the evolution of massive star. The direct measurements are limited by backgrounds at energies above E$_{\rm c.m.}$=2.1 MeV. To overcome this limitation, we have developed a novel technique to study the $^{12}$C($^{12}$C,$\alpha$)$^{20}$Ne reaction by using a...
A multi-purpose experimental instrument, called KoBRA (Korea Broad acceptance Recoil spectrometer and Apparatus), was constructed at the Institute for Rare Isotope Science (IRIS), as a part of the RAON facility in Korea. Stable or rare isotope (RI) beams can be produced using Electron Cyclotron Resonance (ECR) ion sources or the Isotope Separation On-Line (ISOL) system at RAON, and these beams...
In the X-ray bursts, the ${}^{26}$Si($\alpha$, p)${}^{29}$P reaction rate is considered to have a great impact on the light curve. However, there were insufficient experimental data for this reaction because of technical difficulties. In order to measure the cross section of the reaction, a direct measurement was performed at the CNS RI beam separator (CRIB). CRIB produced a ${}^{26}$Si beam...
The synthesis of hyper-heavy elements is investigated under conditions simulating neutron star environment. The constrained molecular dynamics approach is used to simulate low energy collisions of extremely n-rich
nuclei. A new type of the fusion barrier due to a neutron wind is observed when the effect of neutron star environment (screening of Coulomb interaction) is introduced implicitly....
In the era of multi-messenger astronomy, the afterglow of energetic photons emitted from the decay of long-lived neutron-rich actinides is an important observable signal for the rapid neutron-capture process (r-process) which occurred in the compact gravitational objects, i.e., binary neutron star merger (NSM), magneto-hydrodynamic jet supernova (MHDJ SN), and collapsar, which is an explosion...
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...
The $^{17}\mathrm{O}(p,\gamma)^{18}\mathrm{F}$ reaction plays a crucial role in Hydrogen burning via CNO cycle. In particular at temperatures of interest for HBB in AGB stars ($20\,\mathrm{MK}<\mathrm{T}<80\,\mathrm{MK}$) the main contribution to the astrophysical reaction rate comes from the poorly constrained $E_R = 65\,\mathrm{keV}$ resonance. The strength of this resonance has only been...
The origin of neutrino mass and mass hierarchy is one of the biggest unanswered questions in physics. In this article, we propose an astrophysical method so that the supernova (SN) $\nu$-process nucleosynthesis, which is consistent with the mass hierarchy constrained from various $\nu$-oscillation experiments, should provide independent observational signals of nucleosynthetic products in the...
Accretion onto a neutron star induces nuclear reactions which heat the crust. By fitting crust models to the observed thermal evolution of the neutron star after accretion halts and the neutron star enters quiescence, we obtain constraints on the composition and heating of the neutron star crust, notably the crust impurity concentration and the amount of heat deposited per accreted nucleon....
In recent years the plethora of new astronomical observations has shown that the synthesis of heavy elements cannot be explained just by the three traditional processes (s, r, and p). For this reason, new processes have been proposed that are able to explain these new observations. The ``intermediate'' or i process (see e.g. [1]) is one such process and corresponds to neutron densities and...
In this Poster, we present a few examples of recent theoretical activities in IRIS.
Searching for varying dimensionless physical constants presents a meaningful characteristic in experimental and observational studies. One of the most valuable explorations of these variations could depend on the evolution of white dwarf stars. Applying the spectrum of white dwarf star: G191-B2B, we derive a robust limit on the cosmological variation of the gravitational constant...
Nuclear Data Production System (NDPS) is one of the experimental systems at the Rare isotope Accelerator complex for ON-line experiments (RAON). It provides high-energy neutrons up to tens of MeV. The primary objective of NDPS is to accurately measure the neutron-induced nuclear cross sections, particularly for the neutron energy extending up to tens of MeV region. A beam commissioning of NDPS...
Classical novae are common cataclysmic events in the Galaxy involving a binary system. In the early Galaxy these explosions proceeded differently, mainly due to the accretion of sub-solar material onto the white dwarf. It has been proposed that these primordial novae explosions produce a different abundance pattern compared to their classical counterparts [1]. In particular, the nuclear flows...
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...
We present a detailed chemical abundance analysis for about 40 Very Metal-Poor (VMP; [Fe/H] < -2.0), selected from Sloan Digital Sky Survey (SDSS) and Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) surveys. Their high-resolution (R ~ 45,000) spectra were obtained with GEMINI/GRACES, and their atmospheric stellar parameters and various chemical abundance ratios were derived....
Nucleosynthesis of heavy elements has been traditionally attributed to two neutron-capture processes, namely the s and r processes. Recent astronomical observations have revealed stars where the abundance distributions cannot be described by the aforementioned processes and for this reason the astrophysical i process was introduced (i for intermediate between s and r). While we...
Chemical abundance of metal-poor stars is a clue to understand the chemical evolution of the early Universe. However, the metal-poor stars discovered by previous surveys are faint and it is difficult to measure their abundance of many elements with high precision. Therefore, we performed a photometric survey using the wide-field CMOS camera (Tomo-e Gozen Camera) on the Kiso Schmidt telescope...
$^{22}$Na (T$_{1/2}$ = 2.6 y) is of high interest for space-based γ-ray astronomy because its direct observation could constrain classical nova models. Although the characteristic 1275 keV β-delayed γ decay radiation has not been observed yet, future γ-ray telescopes may detect the decay with high sensitivity. To link these observations with nova model predictions, nuclear data are needed. The...
A fast neutron facility, called Nuclear Data Production System (NDPS), was constructed for nuclear science and applications at RAON (Rare Isotope Accelerator complex for ON-line experiments) in Korea. NDPS provides neutron beams not only for nuclear data measurements but also for other applications. NDPS is designed to provide both white and mono-energetic neutrons, using 98 MeV deuteron and...
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...
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.
Photonuclear reactions play an essential role in nucleosynthesis taking place in all sites, e.g., stars, novae, and interstellar gas media. Especially important these reactions are for formation of isotopes heavier than iron. The proton-rich p-nuclei, such as $^{114}Sn$, and $^{113}In$, can be created only via a complex sequence of radiative processes, involving both emission and capture of...
Nuclear mass is known as crucial information to determine the nuclear synthesis pathways occurring in specific stellar environments. These pathways significantly affect the isotopic abundance observed from astronomical observatories. In other words, the compiled mass database, provided through precise measurements, aids in the development of stellar evolution models and enables a deeper...
KoBRA (KOrea Broad acceptance Recoil spectrometer and Apparatus) [1] is a low energy nuclear physics facility at RAON (Rare isotope Accelerator complex for ON-line experiments) [2]. In its early phase of operation, KoBRA will produce RI beams with energies of 5 to 10 MeV/u from stable ion beams (10 ~ 40 MeV/u) delivered from the superconducting linear accelerator SLC3 of RAON. Transfer...
Astrophysical sources of r-process nucleosynthesis pose an ongoing enigma, with conflicting findings in the literature. We investigate three leading candidates—neutron star mergers, magneto-hydrodynamic jets, and collapsars—each associated with distinct stellar progenitor mass ranges. However, an overlooked bias in r-process studies arises from the influence of the initial mass function (IMF),...
The Rare Isotope Accelerator Complex for ON-line Experiments (RAON) provides both stable ion (SI) and rare isotope (RI) beams with wide energy ranges for nuclear physics research and other applications. Ion beams with energies up to a few tens of MeV/nucleon will be delivered to the low-energy experimental systems: the Korea Broad Acceptance Recoil Spectrometer and Apparatus (KoBRA) and the...
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...
The origin of the r-process is unknown for many years, but in 2017, neutron-star merger (NSM) was observed by gravitational waves [1], it was found that NSM is the origin of the r-process by following photometric and spectroscopic observation. However, NSM is unable to explain the origin of the r-process alone. Observations of stellar abundances have found stars which have high [Th/Eu] value...
Superbursts are rare, energetic explosions observed from accreting neutron stars in low-mass X-ray binaries. Associated with the unstable ignition of carbon, superbursts are challenging to model as their energetics are too low and recurrence times too short to be easily accommodated with theoretical models of the neutron star crust and the standard extrapolation of the C12+C12 cross-section to...
The first metal enrichment in the Universe was made by a supernova explosion of a population III star. Second-generation stars were formed from the mixture of the pristine gas and the supernova ejecta. Metal-poor stars were survivors of second-generation stars in the Galactic halo. Their abundance pattern records the metal abundance at their formation and tell us the chemical evolution in the...
We develop an active-target Time Projection Chamber (aTPC) operated in a low-pressure, strong magnetic field. The aTPC comprises a cathode plane, four field-cage planes, a gating GEM (Gas Electron Multipliers) plane, a triple GEM structure, and a pad plane. The pad plane covers 10 x 10 cm2 with 1000 3x3 mm2 square pads. The construction of the detector is in progress, and the expected...
Classical novae are the second most common explosive stellar phenomena in the Universe [1] and, as such, play an important role in the enrichment of the interstellar medium and chemical abundances we observe in the galaxy. One observable, which is key to understanding the processes that drive classical novae, is presolar grains. It is, therefore, important that we are able to characterise the...
Although about 90$\%$ and 50$\%$ of the solar-system Cu and Zn abundances are presumed to originate from the slow neutron-capture process (weak $\textit{s}$-process) during core He and shell C burning in massive stars, their stellar conditions are still poor known. This is because $^{63}$Ni (t$_{1/2}$=101.2$\pm$1.5yr) takes the key as a bottleneck for the synthesis of these nuclei in 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 have developed a LaBr3(Ce) detector array, the HANULball, for measuring high-energy gamma rays from nucleosynthesis reactions near 10 MeV. The HANULball prototype comprises eight LaBr3(Ce) detectors arranged on the surfaces of a truncated cuboctahedron structure. Each LaBr3 crystal has a diameter of 50 mm and a length of 75 mm. The prototype array uses 2-inch photomultiplier tubes to detect...
The study of the p-process is of paramount importance in unraveling the origin of heavy elements in the universe. To describe the entire p-nuclei nucleosynthesis process, a comprehensive reaction network involving over ten thousand nuclear reactions is required, and accurate measurements of some key reaction cross sections are essential for determining reaction rates. 102Pd is one of the more...
The merging of two neutron stars can provide the conditions necessary for the production of the heaviest elements in the universe via the rapid neutron capture process (r-process). When this occurs, an abundance of material is produced lying far from nuclear stability, and the decays of these nuclei produce the electromagnetic signal: the kilonova. Modeling these kilonova signals remains...
Cross-sections for neutron-induced interactions with molybdenum, in particular for the neutron capture reaction, play a significant role in various fields ranging from nuclear astrophysics to safety assessment of conventional nuclear power plants and the development of innovative technologies. Molybdenum is found in pre-solar silicon carbide (SiC) grains and an accurate knowledge of its...
ChETEC-INFRA networks complementary types of research infrastructures to study the origin of the chemical elements in the cosmos: nuclear laboratories supply data on reactions of astrophysical interest, optical telescopes and accelerator mass spectrometers collect elemental and isotopic abundance data, and high-performance computing facilities perform stellar structure and nucleosynthesis...
RAON aims to produce rare isotope beams through proton-induced fission of uranium-238. In this study, we utilize the Langevin method to predict the mass distribution by plotting trajectories based on the potential surface of compound nuclei, integrating the Liquid Drop Model (LDM) and the Shell model (SM). To enhance the shell effect at high excitation energy, we employ a multi-chance fission...
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...
The supernova, which is the event at the last moment of the massive star's life, is the next promising candidate as the gravitational wave source. Up to now, gravitational waves from supernova explosions have been mainly discussed via numerical simulation. These results tell us the existence of the gravitational waves whose frequencies increase from a few hundred hertz up to kHz within a...
The stellar (n, γ) cross section data for the mass numbers around A ≈ 160 are of key importance to nucleosynthesis in the main component of the slow neutron capture process, which occurs in the thermally pulsing asymptotic giant branch (TP–AGB). The new measurement of (n, γ) cross sections for 159Tb was performed using the C6D6 detector system at the back streaming white neutron beam line...
Systematic studies of core-collapse supernovae (CCSNe) 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...
The $^{12}$C(p,$\gamma$)$^{13}$N is the kick off reaction of the CNO cycle, active in massive star core Hydrogen burning and RGB and AGB star H-shell burning, at typical temperatures between 0.02 and 0.1 GK. The $^{12}$C(p,$\gamma$)$^{13}$N reaction plays a key role in many scenarios, being the $^{13}$N decay one of the solar neutrino source and the main responsible for the $^{13}$C pocket in...
An accurate understanding of the slowest reaction of the CNO cycle, the $^{14}$N(p,$\gamma$)$^{15}$O, is crucial for estimating the lifetimes of massive stars and globular clusters, as well as determining the CNO neutrino flux from the Sun. Despite the efforts of many groups over the years, including pioneering underground measurements made by the LUNA collaboration, this reaction remains the...
It is widely accepted that the slow (s-process) and rapid (r-process) scenarios of neutron captures contribute to the solar abundances of trans-Fe nuclei.
The yields of up-to-date and totally independent models for s- and r-process show a general good and complementary agreement in reproducing the Solar System abundances. However, some local discrepancies do occur and this fact could hint to...
We investigate the sensitivity of the r-process nucleosynthesis to intermediate-mass nuclear reactions. Many nuclear reactions with neutron-rich nuclei are still uncertain and the r-process sites are not fully understood. We use Meyer's code for the reaction network calculation and update some reaction rates. Then, we calculate the r-process nucleosynthesis in the core-collapsed supernovae for...
$^{13}$C($\alpha$,n)$^{16}$O is the dominant neutron source of the s- and i-processes. The cross section of this reaction is extremely low at stellar energies(~10$^{-14}$ Barn), which brings large errors of the measurements and makes it difficult to constrain the theoretical extrapolation.
To precisely measure the cross section of the $^{13}$C($\alpha$,n)$^{16}$O reaction, we designed a...
Galactic chemical evolution (“GCE”) is a great tool to probe the influence of various astrophysical sites on the observed abundances of stars. We use the high resolution ((20 pc)^3 /cell) inhomogeneous GCE tool “ICE” to estimate the impact of two main supernova (“SN”) properties on observed stellar abundances:
First, we will show that supernova yields need to be metallicity dependent in...
The abundance of 26Al carries a special role in astrophysics, since it probes active nucleosynthesis in the MilkyWay and constrains the Galactic core-collapse supernovae rate. It is estimated through
the detection of the 1809 keV-line and from the superabundance of 26Mg in comparison with the most abundant Mg isotope (A=24) in meteorites. For this reason, high precision is necessary also in...
Studying the galactic chemical evolution with short lived radioisotopes (SLRs) has a significant advantage over using stable elements: Due to their radioactive decay, SLRs carry additional timing information on astrophysical nucleosynthesis sites.
We can use meteoritic abundance data in conjunction with a chemical evolution model to constrain the physical conditions in the last rapid...
The observed surface abundance distribution of Carbon-enhanced metal-poor (CEMP) r/s-stars suggests that these stars have been polluted by an intermediate neutron-capture process (the so-called i-process) occurring at intermediate neutron densities between the r- and s-processes. Triggered by the ingestion of protons inside a convective He-burning zone, the i-process could be hosted in several...
Currently, the explanation behind the explosion mechanism of core collapse supernovae is yet to be fully understood. New insight to this phenomena may come through observations of $^{44}$Ti cosmic $\gamma$ rays; this technique compares the observed flux of cosmic $^{44}$Ti $\gamma$ rays to that predicted by state-of-the-art models of supernova explosions. In doing so, the mass cut point of the...
The reaction rate of the carbon fusion reaction is one of the basic inputs in the stellar model to understand the final stages of the massive star evolution. However, this reaction rate is yet uncertain because it depends on the extrapolation methods. The cross-section measurement for this reaction is challenging because the energy range relevant to the stellar evolution is much below the...
The COREA (Carbon Oxygen Reaction Experiment with Active-target TPC) is an experiment to measure the precise cross-section of the 12C(α,𝛄)16O reaction in stellar nucleosynthesis. The reaction rate of 12C(α,𝛄)16O determines the 12C/16O abundance ratio in the universe and the entire scenario of the stellar nucleosynthesis after the helium burning up to the Fe core in the last years of stellar...
IBS has recently constructed a new underground laboratory, Yemilab, in Korea. It is 1000 meters underground and spacious with more than 3000 m^2 experimental area. The Center for Underground Physics has developed programs for weakly interacting dark matter searches with scintillators and low-temperature detectors. We also have plans to search the rare nuclear decays, such as neutrinoless...
There is a distinguished history of nuclear astrophysics research at the Notre Dame Nuclear Science Lab (NSL). This has been fostered by University investment and strong support from the National Science Foundation. The NSL provides the research base for some 20 Notre Dame faculty members and approximately 35 graduate students as well as supporting the research programs of a number of...
Astrophysical reactions involving radioactive isotopes (RI) often play an important role
in explosive stellar environments. Although the RI are seldom seen on the earth due to
the finite lifetime, they do exist in stars, and contribute to the evolution and thermal
dynamics of stellar objects. Experimental efforts have been made for the studies on such
RI-involving reactions.
CRIB (CNS...
The Triangle Universities Nuclear Laboratory (TUNL) is home to one of the only functioning magnetic Enge split-pole spectrographs in North America. The spectrograph was recommissioned in 2017 and has been used to perform a suite of experiments aimed at constraining nucleosynthesis in stars. An overview will be presented of the successful experiments and results that have been performed at the...
Several ($\alpha,p$) reactions on proton-rich nuclei are among the most important nuclear reactions occurring during Type I X-ray bursts. However, large uncertainties remain in these reaction rates due to the lack of direct measurements. The Array for Nuclear Astrophysics and Structure with Exotic Nuclei (ANASEN) is a gas target and charged particle detector designed for studying ($\alpha,p$)...
The merging of two neutron stars is a true multimessenger event that includes gravitational waves, an electromagnetic signal, and the emission of enormous numbers of neutrinos. In order to understand these signals we need a careful accounting of the microphysics that occurs during and after the merger. I will focus on the elements produced in these objects and the effect of two aspects of this...
The properties of nuclear matter at extremely high densities and temperatures remain a mystery. This talk discusses two environments for which the nuclear matter can be found at the highest densities. These are: during the collapse of the core of a massive star to form a supernova or black hole; and during the merger of two neutron stars to form a black hole. Here, we highlight recent...
We study the sensitivity of the r-process nucleosynthesis to the nuclear reactions of light nuclei.
We first update nuclear reaction data in Libnucnet code if available in experiments. We then calculate the r-process nucleosynthesis in the core-collapse supernovae and collapsar. For core-collapse supernovae we consider two different scenarios: the magnetohydrodynamic (MHD) jet model and a...
Metal-poor stars are thought to have the result of nucleosynthesis in the early stages of galaxy formation in their atmospheres. A variety of surveys and follow-up observations have been performed to determine detailed abundance patterns for many metal-poor stars. The r-process, which provides about a half of the elements heavier than iron, is thought to be caused by neutron star mergers....
Magnetorotational-driven supernovae (MRNSe) are a peculiar type of core-collapse SNe. Their progenitors are fast-rotating massive stars with strong magnetic fields and they are candidates for the central engine of hypernovae and gamma-ray bursts. They are also expected to be astronomical sites for the r-process, as they have a different explosion mechanism from regular SNe. MRSNe may have very...
We construct new effective interactions using the relativistic mean-field model with the isoscalar- and isovector-meson mixing. Taking into account the results of neutron skin thickness of $^{208}$Pb and $^{48}$Ca by the PREX-2 and CREX experiments as well as the particle flow data in heavy-ion collisions, the observed mass of PSR J0740+6620, and the tidal deformability of a neutron star from...
The equation of state (EOS) for dense matter is one of the crucial ingredients in numerical simulations for astrophysical phenomena, such as core-collapse supernovae, cooling of nascent proto-neutron stars, and binary neutron star mergers. While considerable efforts have been devoted to understanding the dense-matter EOS from terrestrial experiments, astrophysical observations, and theoretical...
Stars play a key role in the Cosmos through the light they shine, the chemical elements they produce and the kinetic energy they inject into their surroundings via winds and supernova explosions. For many decades, our understanding of the structure, evolution and fate of stars has greatly benefitted from comparing spherically symmetric, one-dimensional (1D) theoretical models to a variety of...
Accreting white dwarfs in interacting binary systems are closely related to explosive events like novae and Type Ia supernovae, which play an important role in the chemical evolution of the universe. Although numerous studies on the evolution of accreting white dwarfs have been presented in the literature, there has been a relatively limited focus on exploring the impact of rotation and...
Massive stars (10 solar masses and up) play an important role in the synthesis of new elements in the Universe. They enrich the interstellar medium with these newly synthesized isotopes via their stellar winds and via their final supernova explosions. To understand the nuclear yields of these stars, especially before the supernova explosion, there are three key ingredients; the nuclear...
Our knowledge of stellar evolution is limited by uncertainties coming from complex multi-dimensional processes in stellar interiors, usually reproduced in 1D stellar models with simplifying prescriptions. 3D hydrodynamic models can improve these prescriptions by studying realistic multi-D processes, usually for a short timerange (minutes or hours). Recent advances in computing resources are...
Almost all of the nuclei in the cosmos originate from stars. Low-mass (~1-8M⊙) stars are thought to synthesise a large fraction of the universe’s carbon, nitrogen, and fluorine, and about half of all elements heavier than iron making them an important ingredient in galactic chemical evolution (GCE) models. Low mass stars synthesise material through a variety of nuclear processes such as...
The $^{18}$Ne($\alpha$,$p$)$^{21}$Na 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 $^{22}$Mg by measuring the $\alpha$ resonant scattering on $^{18}$Ne in inverse kinematics. The $^{18}$Ne rare isotope beam was produced at...
Rapid neutron capture nucleosynthesis (the r-process) produces nearly half of the nuclei heavier than iron in explosive stellar scenarios.
The solar system r-process residual abundances show two peaks located at $A\sim 130$ and $A\sim 195$. Between these peaks lies the Rare-Earth Peak (REP), a distinct but small peak at mass number $A\sim 160$ that arises from the freeze-out during the final...
Half of the elements heavier than iron are produced by a sequence of neutron captures, beta-decays and fission known as r-process. It requires an astrophysical site that ejects material with extreme neutron rich conditions. Once the r-process ends, the radioactive decay of the freshly synthesized material is able to power an electromagnetic transient with a typical intrinsic luminosity. Such...
More than 30 years after the discovery of SN 1987A, it entered a phase of a young supernova remnant. It is considered that molecules and dust are formed in the ejecta. Actually, recent ALMA observations (Abellán et al. 2017) have revealed that the 3D distribution of carbon monoxide (CO) and silicon monoxide (SiO) is rather non-spherical and lumpy. However, how molecules are formed in...
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 ...
Neutron-capture processes made most of the abundances of heavy elements in the Solar System, however they cannot produce a number of rare proton-rich stable isotopes lying on the left side of the valley of stability. The p-process, or $\gamma$-process, is recognised and generally accepted as a feasible process for the synthesis of proton-rich nuclei in core collapse supernovae. However this...
A huge number of neutrinos emitted in a supernova explosion interact with a dense plasma. The interaction between neutrinos and electrons remarkably changes the neutrino oscillation probability at the specific electron density, known as the Mikheyev–Smirnov–Wolfenstein (MSW) resonance effect. Previous studies for the neutrino-process in core-collapsing supernova have well-established the...
Nuclear chronometer provides an independent dating technique for the cosmos by predicting the ages of the oldest stars. Similar to geochronology, the ages are determined by comparing the present and initial abundances of long-lived radioactive nuclides. In nuclear cosmochronology, the present abundances can be obtained from the astrophysical observations whereas the initial abundances have to...
Indirect methods play an important role in constraining the astrophysical rates of nuclear reactions. This talk will review several recent indirect studies that provided almost model-independent constraints for the key rates.
Neutron-upscattering enhancement of the triple-alpha reaction responsible for the production of carbon, suggested in [1], was investigated by measuring a time-inverse...
A variety of nucleosynthesis processes operate in our universe, producing elements across the nuclear chart. Using a range of tools and techniques, we can probe the nuclear reactions that comprise these processes. In explosive rp-process environments, direct reactions are possible using gaseous targets such as JENSA, with input from indirect techniques such as transfer reactions on both stable...
The hadronic deexcitation of the Hoyle state in 12C induced by inelastic scatterings of particles can enhance the triple-alpha reaction and the resultant accumulated seed nuclei prevent the synthesis of the heavier elements [1]. Quite recently, neutron-induced deexcitation cross sections were measured experimentally and this effect turns out to be less significant [2]. It therefore is even...
Knowledge of the $^{19}$Ne resonance information near the proton threshold (E$_{x}$=6.410 MeV) is important for studying the $^{18}$F($p$,$\alpha$)$^{15}$O nuclear reaction rate in a classical nova [1-4]. Several states in the vicinity of the proton threshold still have not been observed in $^{19}$Ne but were predicted by assuming isospin symmetry from its mirror state in $^{19}$F [5,6]. The...
I will review the current understanding of the nuclear physics of accreting neutron stars, including the rp-process and processes involving neutron rich nuclei, and their relation to observables such as X-ray bursts and the cooling of transiently accreting neutron stars. This will include new results from experiments on rp-process reactions and measurements related to crust Urca processes,...
We use the type-I X-ray burst models, constructed by the one-dimensional multi-zone hydrodynamic KEPLER code [1], and complying with the burst light curves and recurrence times of the observed GS 1826−24 clocked bursts and SAX J1808.4−3658 photospheric radius expansion (PRE) bursts to investigate the combined impact of the latest 22Mg(α,p)25Al [2], 56Ni(p,γ)57Cu [3], 57Cu(p,γ)58Zn [4],...
