The characteristic 1.157 MeV $\gamma$-rays from the radioactive decay of $^{44}$Ti ($t_{1/2}$ = 59.1 y) provide information about supernova explosion phenomena. The study of $^{44}$Ti($\alpha$,$p$)$^{47}$V reaction rates is essential for predicting the abundance of $^{44}$Ti. To study the properties of energy levels in $^{48}$Cr, $^{50}$Cr($p$,$t$)$^{48}$Cr reaction will be performed at the...
Microchannel plate (MCP) detectors are widely utilized in experimental setups for nuclear physics studies at low and medium energies. These detectors offer excellent timing resolution and precise position information via delay-line anode readouts [1, 2]. As a result, MCP detectors have found significant applications in nuclear physics experiments requiring high precision and resolution in both...
A search for resonance excitation of $^7$Li by the solar axions has been realized with the Li$_2$MoO$_4$ scintillation bolometers, used to search for the neutrinoless double beta decay of $^{100}$Mo in the AMoRE project at the phase-1 experiment. The detection of 478 keV de-excitation gamma of $^7$Li$^*$ would indicate the existence of solar axion. The five Li$_2$MoO$_4$ crystals, used as a...
The AMoRE collaboration aims to investigate for rare processes, including neutrinoless double electron capture (0$\nu$2EC), an intriguing alternative to neutrinoless double-beta decay for exploring the fundamental nature of neutrinos. In this study, we present a comprehensive analysis of the 0$\nu$2EC process in $^{40}$Ca, utilizing the high-purity, enriched calcium molybdate...
The existence of magic numbers of protons and neutrons in nuclei is essential for understanding the nuclear structure and fundamental nuclear forces. Over decades, researchers have conducted theoretical and experimental studies on a new magic number, Z(N)=6, focusing on observables such as radii, binding energy, electromagnetic transition, and nucleon separation energies. We performed ab...
Designing and optimizing target structures is one of the most critical steps in high-intensity laser experiments, like laser-driven neutron sources, which are increasingly recognized for their compactness and portability. Here, we propose an AI-assisted target design approach that leverages artificial intelligence algorithms in combination with particle-in-cell (PIC) simulations. This newly...
We use the Continuum Discretized Coupled Channels (CDCC) method to study the total,Coulomb and nuclear breakups in 6,7 Li on 58 Ni and 208 Pb target masses. The objective is to study whether the target charge can explain the importance of the Coulomb breakup cross sections over its nuclear breakup cross sections. Since this reaction is regarded as the
Coulomb dominant. We observed that the...
Studies of Ordinary Muon Capture (OMC) provide crucial insights into nuclear matrix elements (NMEs) that play a crucial role for neutrino ($\nu$) mass studies by double beta decay (DBD) and astro-$\nu$ nuclear interactions. OMC on a nucleus $^A_Z$X, with $A$ and $Z$ being the mass and atomic numbers, proceeds via a proton-neutron conversion, leading to the nuclear excitation around 0-50 MeV...
In a variety of applications, such as medical diagnostics, nuclear safety, and environmental monitoring, $\gamma$-ray spectrometry is essential for the analysis of radioactive isotopes. The goal of this research is to create a $\gamma$-ray spectrometry system that is improved by Kolmogorov-Arnold Networks (KAN), a machine learning algorithm renowned for its effectiveness with complex data and...
This work has obtained the constraints on the density dependence of the symmetry energy from neutron-skin thickness data of PREX and CREX as well as neutron-star data of GW170817, PSR J0030+0451, and PSR J0740+6620 using a Bayesian approach, based on the standard Skyrme-Hartree Fock (SHF) model and its extension as well as the relativistic mean-field (RMF) model.
While the neutron-skin...
Electromagnetic calorimeters are key to deep inelastic scattering experiments. At the Electron-Ion Collider (EIC), in the ePIC experiment, the Barrel Imaging Calorimeter (BIC) will be an electromagnetic calorimeter located in the barrel region. It consists of alternating layers of Lead and Scintillating Fibers (Pb/SciFi) for energy measurement, interleaved with silicon pixel detectors for...
Newcomb discovered that natural datasets often exhibit a non-uniform distribution of leading digits, with smaller digits occurring more frequently. Benford later formalized this observation with a mathematical law, providing a precise formula for the expected distribution of the first significant digits based on logarithmic probabilities. Benford's law states the probability of a number...
The beta decay of the heaviest known N=82 nuclide 156W was recently reported and found to exhibit a different decay pattern to152Yb and their lighter isotones [1]. This work investigates the beta decays of the intermediate isotone 154Hf to learn about the evolution with increasing atomic number of the beta decays of even-even N=82 isotones. Although a microsecond isomer in 154Hf has been...
The Seyler-Blanchard (SB) effective interaction has been commonly employed to obtain the fundamental properties of nuclear matter and the equation of state. The Seyler-Blanchard nucleon-nucleon (NN) effective interaction consists of an attractive Yukawa function multiplied by a quadratic momentum-dependent term. This interaction leads to the nuclear matter Equation of State.
In this study,...
Cluster formation is a fundamental phenomenon in nuclear physics and is crucial for understanding nuclear structure and dynamics. To study cluster formation in nuclei, we use quasi-free knockout reactions with a proton probe to directly measure clusters formed in the nucleus. This approach, combined with inverse kinematics, allows measurements over a wide range of nuclei.
To implement this...
A significant milestone in the field of gamma-ray spectroscopy has been the development of highly-segmented germanium detectors to meet the growing need of excellent spectroscopic capabilities. These detectors combined with advanced techniques such as, Pulse Shape Analysis (PSA) and Gamma-Ray Tracking (GRT) are considered as highly promising options for gamma-ray imaging applications [1]. The...
This poster presents a study on using neutrino induced charge current coherent pion production ($\nu\text{CC-Coh}\pi$) as a tool for constraining the neutrino flux at the neutrino experiments, specifically the Deep Underground Neutrino Experiment (DUNE). We develop a procedure that leverages measured $\nu\text{CC-Coh}\pi$ events to fit for the neutrino flux while simultaneously accounting for...
This study focuses on the deuteron-induced inclusive breakup reaction and investigates the $(d, pX)$ and $(d, nX)$ channels for light and medium mass nuclei. To study the double differential cross section of nonelastic breakup, we employed the models of Ichimura, Austern, and Vincent [Phys. Rev. C. 32, 431 (1985)] and the Glauber model with the quantum $S$-matrix [Phys. Rev. C. 80. 014604...
The KAPAE Phase II detector was developed to investigate the invisible decay of positronium, with a focus on exploring theoretical phenomena such as milli-charged particles, mirror worlds, new light X-bosons, extra dimensions, and dark photons. As the first step, this study focuses on the search for dark photons through the decay of para-positronium. The detector is maintained at -30°C and...
Study of quantum many-body phenomena is one of most exciting issues in modern physics. Since the involvement of various degrees of freedom, the nuclear matter is a promising candidate for the investigation. Meanwhile, the superconductivity as a result of the condensation of Cooper pairs that are formed by two electrons, can be successfully described by the Bardeen-Cooper-Schrieffer (BCS)...
In this study, we revisit the quasi-elastic scattering angular distributions for the 10,11B + 232Th systems at near-barrier energies, initially measured and analyzed by Dubey et al. (PRC 94, 064610 (2016)). In the previous analysis, the quasi-elastic cross-section included contributions from inelastic scattering to the low-lying excited states (2+ at 49.37 keV and 4+ at 162.12 keV) of the...
Cryogenic targets in gas or liquid are essential for generating nuclear reactions in nuclear astrophysics and structure studies. The cryogenic targets possess high purity and density to compensate for low beam intensities, thereby reducing unnecessary background events and enhancing reaction yields in nuclear physics experiments. At the Center for Exotic Nuclear Studies (CENS), Institute for...
The Rare Isotope Accelerator complex ON-line experiment (RAON) is being developed as the flagship Radioactive Isotope (RI) facility for fundamental researches and applications in Korea.
RAON involves the use of RI beams for the production of RI, with purpose of expand our research filed to encompass with more exotic region.
Achieving this initiative, a high-power Isotope Separator On-Line...
The enhancement of the detector capability and reconstruction software of CMS enable significant improvement in track based reconstruction of the open heavy-flavor hadrons. This poster presents the latest performance of the D-meson reconstruction using PbPb collisions data recorded by the CMS experiment at the LHC run3. The reported performance includes track reconstruction and secondary...
The dynamical SU(3) symmetry of the Interacting Boson Model (IBM) has been employed to study the systematic of superdeformed (SD) bands in Pb isotopes for the first time. This SU(3) symmetry describes the characteristics of deformed nuclei in a generalized way. For each SD band in Pb isotopes, the level spins are suggested. The model parameters are determined using a computer-based program to...
The neutrinoless double beta decay ($0\nu\beta\beta$) event, if observed, would verify the Majorana nature of neutrinos and provide strong support for one of the hypotheses explaining the matter-dominated universe. As a part of the CANDLES experiment, aiming to search for $0\nu\beta\beta$ of $^{48}$Ca, we develop CaF$_{2}$ detectors operating at millikelvin (mK) temperatures for phonon and...
Active Target Time Projection Chamber (AT-TPC) is one of state-of-the-art particle detectors which allows a precise measurement of nuclear reactions using rare isotope beams. A new Active Target TPC for Multiple nuclear physics eXperiments (AToM-X) is under development at the Center for Exotic Nuclear Studies (CENS). It consists of a highly segmented Time Projection Chamber (TPC) using a...
The isomeric state of thorium-229 ($^{229}$Th) can be excited using a vacuum ultraviolet (VUV) laser [1-3] and is expected to facilitate a nuclear clock. The realization of a nuclear clock is expected to have a wide range of applications, from basic physics to practical use in society as a high-precision optical clock. To advance the understanding of $^{229}$Th isomer and its properties, we...
The triple alpha process is a set of reactions, which produces $^{12}$C from three alpha particles in stellar nucleosynthesis. The $0_2^+$ resonance of $^{12}$C, known as the Hoyle state, plays an important role in that process. The Hoyle state de-excites to the ground state of $^{12}$C with low probability by mainly radiative de-excitations under typical stellar conditions. In a hot and dense...
The rapid neutron capture process (r-process) has been thought to be the origin of elements heavier than iron, such as gold and platinum.[1] Although the r-process is predicted to terminate in the fission of actinide nuclides, theoretical predictions for the decay properties of the endpoint nuclides have large uncertainty because of depending strongly on the mass model[2] and the astronomical...
Structure and correlations of nuclei at and beyond the neutron drip line have attracted lots of attention in the last decades [1,2]. Strongly correlated neutrons may also form neutron clusters (e.g., n, 4n). Despite many experimental and theoretical efforts, the properties of these neutron clusters still remain elusive [3,4].
To study the structure of extremely neutron-rich nuclei and the...
There is still a significant lack of experimental data on the alpha-capture process starting from $^{4}\mathrm{He}$ near the Gamow window, prompting numerous attempts worldwide to address this gap. Among them, we are conducting the COREA (Carbon Oxygen Reaction Experiment with Active-target TPC) experiment to measure the cross-section of the $^{12}\mathrm{C}(\alpha, \gamma)^{16}\mathrm{O}$...
$\alpha$-induced reactions play critical roles in nucleosynthesis processes such as the s-process, r-process and $\alpha$p process occurring in explosive stellar environments. However, significant uncertainties remain due to the difficulty of direct reaction measurements, particularly for the low cross sections of $\alpha$-induced reactions at energies associated with stellar temperatures....
Generalized Parton Distributions (GPD) are multidimensional structure functions parameterizing the interaction of a particle with the constituent partons of hadrons, encoding information like the spatial distribution of partons or the mechanical and spin properties of hadrons through the correlation between the longitudinal momentum and transverse position of partons inside the hadron. While...
We investigate the two-vector meson production near threshold via $\bar p p\to\phi\phi$ equation using an effective Lagrangian method. Our calculations suggest that the $N^{(*)}$ exchange in the t- and u-channel contributes to the total cross section of reactions near threshold. Contributions form $f_0$ and $f_2$ mesons in the s-channel lead to a peaking structure in the total cross section....
Study of nuclei near proton shell closure $Z=82$ is important, as interplay between different shapes has been observed in this region. Recent experiments show triaxial shapes, in addition to the symmetric oblate shapes, in odd-odd Tl nuclei in A $\sim$ 190 region. The proton Fermi level for Tl lies near the $3s_{1/2}$ orbital, but highly shape driving $h_{9/2}$ and $i_{13/2}$ Nilsson orbitals...
The General Description of Fission Observables (GEF) code is widely used for predicting various fission observables, including fission product mass distributions. Accurate fission product yield (FPY) predictions are crucial for applications in reactor physics, nuclear security, and spent fuel management. Traditional models, such as the 5-Gaussian model, rely on a limited parameter set and may...
Isospin symmetry implies that the nuclear force is nearly equal between the proton-proton, neutron-neutron and proton-neutron pairs in the atomic nucleus. To probe this symmetry, one may study the so-called ''mirror nuclei" that have interchanged numbers of protons and neutrons, and thus should have analogue structures. The difference in excitation energy of the states characterized by the...
Configuration-interaction shell model (CISM) has been a powerful tool for investigating the nuclear structure properties. Within the CISM framework, one chooses the model space, constructs the effective Hamiltonian, and diagonalizes the Hamiltonian matrix. However, investigation on the neutron-rich medium and heavy nuclei is challenging due to the insufficient knowledge on the effective...
Nuclear shapes, or deformations, range from spherical harmonic vibrators to axially symmetric and γ-unstable (axially asymmetric) rotors, which represent the idealized limits of nuclear structure. These configurations correspond to distinct dynamical symmetries encoded within the interacting boson approximation (IBA): the spherical vibrator is associated with U(5), the axially symmetric rotor...
Neutron stars possess extremely high surface magnetic fields and densities of mass. The neutron star's densities can far exceed those found in atomic nuclei. Studying their structure provides insights into the behavior of fundamental particles, particularly neutrons, under extreme conditions that are very hard to recreate in terrestrial laboratories. Although the precise equation of state...
The triple-alpha process, crucial for the synthesis of carbon-12 in stellar environments, primarily relies on the Hoyle state at 7.654 MeV. While de-excitation dominantly proceeds through radiative decay, particle-induced scattering $^{12}$C(HS)($p$,$p'$)$^{12}$C has been proposed as an additional enhancement channel under high-temperature and high-density conditions. A previous experiment ...
The Daejeon16 NN interaction, based on SRG-evolved N3LO interaction and fitted to light nuclei via Okubo-Lee-Suzuki transformation, effectively reproduces many properties of narrow states in p-shell nuclei without explicit three-nucleon forces. We are extending this approach to describe the nuclei near Z=8 including the light sd-shell.
The goal of this study is to develop a liquid scintillator with an increased water ratio to enhance cost-effectiveness, unlike conventional liquid scintillators that use costly solvents or surfactants. To achieve this, various solvents, solutes, and mixing methods were tested, and acetone was selected as the optimal solvent. As a result, a liquid scintillator with a water content of 70% was...
The aim of this study is to develop and investigate the characteristics of a liquid scintillator (LS) using a perovskite quantum dot structure. To date, there have been no specific examples of using perovskite structures for particle detectors in high-energy or nuclear physics. So this study aims to develop a new form of next-generation liquid scintillator that has not been researched before....
We investigate the Gamow-Teller (GT) transition strength distributions of strongly deformed nuclei, 24,26Mg,as well as of 18O. The calculations are performed within a deformed quasiparticle random-phase approximation
which explicitly includes the deformation degree of freedom in the Skyrme-Hartree-Fock and random-phase approximation calculations. The residual particle-particle (p-p)...
Alpha decay and proton emission are the dominant decay modes observed in proton-rich nuclei near the proton drip line. Investigating these phenomena provides valuable insights into the properties of exotic nuclei far from stability. In this study, we examine the half-lives for alpha decay and proton emission within the semiclassical WKB approximation framework, using the Deformed Relativistic...
Nuclear masses and decay properties of radioactive isotopes (RIs) that are far from stable are crucial for studying the fundamental properties of nuclei. In particular, high-precision measurements, such as the study of fundamental interactions, require a highly controlled environment. The purity and quality of the beam have paramount of importance due to the nature of these measurements....
Infrared (IR) spectroscopy offers a powerful approach to analyzing the purity of linear alkyl benzene (LAB)-based liquid scintillators. While previous studies have largely focused on electronic transitions using ultraviolet-visible spectroscopy, this work explores the vibrational transitions captured by IR spectroscopy. By examining the unique IR spectral characteristics of these solutions,...
Nuclear physics is a foundation of modern science, providing critical insights into the fundamental structure of matter, nuclear reactions, and processes governing the universe's evolution. However, the field is characterized by immense computational challenges due to the inherently complex nature of nuclear systems \cite{national2001physics}. Modeling nuclear structure involves solving...
nvestigating Branching Points and Isomeric Influences in the s-Process
near A ∼ 180
Shrikant Thorat1,2, Sutanu Bhattacharya3, B. Maheshwari4, A.K.Jain1,5, A. Goel1, and R. Palit2
1Amity Institute of Nuclear Science & Technology, Amity University Uttar Pradesh, Noida, India
2Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai, India
3Racah Institute...
Various materials have been developed for radiation protection across multiple applications. These materials must meet several criteria, including low cost and lightweight, to ensure ease of access and handling. Cement-based materials are among the effective shielding compounds due to their superior radiation attenuation properties, along with other significant advantages.
This study aims to...
The study of excited nuclear states near shell closures serves as a vital framework for advancing our understanding of nuclear structure. While neutron-rich nuclei around magic numbers far from the line of stability, such as N = 82, have been extensively explored using conventional production methods like fission and fragmentation, the region near the doubly magic nucleus 208Pb along the N=126...
In present work, we have taken the expansion of this two variable (Z,N) Taylor series upto fourth order of its derivative and have obtained an elaborate as well as a concise-averaged expression for the estimation of these residual n-p interactions. The parameters of fitting seem to differ by an appreciable amount for different species of the nuclei, thus, separate parameters for even-even,...
Introduction
The concept of isospin was put forward by Heisenberg to describe the charge independence property of nuclear forces, and a detailed theoretical framework of the same was provided by Wigner [1]. The isospin quantum number $T$ treats protons and neutrons on the same footing and puts strict selection rules on nuclear reactions, decays, and transitions [2]. These selection...
The investigation of collective motion in nuclei, especially through vibrational modes, presents a valuable approach to examining various aspects of the structure of quantal many-body systems. One example of such a collective nuclear vibration is isovector giant dipole resonance (IVGDR) which is described as an out-of-phase oscillation between neutrons and protons. Generally, the width...
Korean MIP Timing Detector(MTD) group is contributing the Endcap Timing Layer (ETL) of the MTD. ETL uses LGAD sensors with time resolution has 30~50ps that makes Particle Identification(PID) possible in numerous pile-up. This talk aims to present the activity of the Korean MTD group.
The aim of the LEGEND experiment is searching for neutrinoless double beta (0νββ) decay of Ge-76. The detection of this lepton number violating process would be a direct proof of the Majorana nature of neutrinos and would indicate the existence of a New Physics beyond the Standard Model. Its first stage, so-called LEGEND-200, operates up to 200 kg of bare enriched high-purity germanium (HPGe)...
In this study, laser spectroscopy was successfully performed on a sodium (Na) atomic beam using laser spectroscopic
techniques. By directing a laser beam parallel to a 20 keV Na beam generated from a silicon carbide (SiC) target,
fluorescence variations were measured based on the acceleration voltage of the atomic beam, allowing spectroscopic
signals of 23Na, 22Na and
21Na to be...
Near- and sub-barrier fusion reactions [1,2] between doubly magic nuclei are important benchmarks for theoretical models to reproduce the experimental evidence. The cases of 16O + 16O, 48Ca + 48Ca, and 16O + 208Pb have been measured. We add 40Ca + 90Zr even if Z=40 is not a major shell closure. 48Ca + 208Pb populates superheavy nuclei and involves different features.
Surprisingly, no...
Laser spectroscopy can accurately measure the hyperfine structure and isotope shifts of atoms and ions, enabling the extraction of fundamental nuclear properties such as spins, magnetic moments, electric quadrupole moments, and charge radii in a nuclear-model-independent manner [1]. Laser resonance ionization spectroscopy (RIS) is one of the approaches to measure the HFS spectrum with higher...
Nuclear mass is a fundamental quantity of an atomic nucleus. Theoretically, many methods have been developed to describe and predict nuclear masses. Simple relations of masses between two mirror nuclei, which correlate to the difference of Coulomb energies, were suggested by Bao et al. in 2016 and were proved to be very accurate and useful in predicting masses of proton-rich nuclei with the...
The nuclear modification of quarkonium production serves as crucial evidence for the deconfined QCD medium production in nuclear collisions. This modification is shaped not only by medium-induced dissociation but also by a variety of initial- and final-state effects. The production of excited charmonium states in pPb collisions presents a controlled setting to further investigate these...
In this presentation, we will show the second-order($v_2$) and the third-order($v_3$) Fourier coefficients of charmonia measured in PbPb collisions at 5.02 TeV with CMS experiment. The understanding of the in-medium effect of quarkonia in heavy ion collisions requires observation of various physical objects. The coefficients describing the azimuthal anisotropy were measured for prompt and...
In this study, the cross-sections of natNd(p,x) reactions were determined up to 100 MeV using off-line γ-ray spectrometry and a stacked-foil activation technique. The irradiation was carried out at the Korea Multi-purpose Accelerator Complex (KOMAC) with 100 MeV proton beams, and Al and Cu foils were utilized to monitor the beam flux. The induced radioactivity of each irradiated sample was...
To pin down the properties of the three-nucleon forces, we are planning to measure the spin correlation coefficients for deuteron-proton scattering around 100 MeV/u at RIKEN RIBF. For the measurement of the spin correlation coefficients, the polarized deuteron beam and the polarized proton target are required.
The polarized ion source (PIS) was renewed after a long break of the polarized...
The cross section of beauty jets can be described by perturbative quantum chromodynamics (pQCD), even at low (p_T), due to their large mass. Moreover, beauty jets provide valuable insights into how the partonic mass influences fragmentation. One of the primary challenges in measuring beauty jets is accurately identifying them within the overall jet sample. Thanks to the upgrades to tracking...
Electric monopole (E0) transitions are closely tied to shape coexistence in atomic nuclei. The E0 transition strength, ρ$^{2}$(E0), is directly connected to nuclear mean-square charge radii. A large E0 transition strength is a reliable indicator of nuclear shape coexistence and strong mixing between admixture states of different deformation. Electric monopole transitions are possible between...
In the nuclear mass surface, the (two) proton- or (two) neutron-separation energies, deduced from the nuclear masses, actually the variations of them along the isotopic or isotonic chain illustrates the evolution of nuclear shell structure of the atomic nuclei. From the systematic study, we can obtain insights on the nuclear interaction between the nucleons.
To understand the stellar...
The theoretical modeling of nuclear structures and their excitation mechanisms poses significant challenges. One fundamental process is Nuclear Excitation by Electron Capture (NEEC). Recent advancements in nuclear theory have employed first-principles simulations to predict NEEC rates across various experimental setups. In this paper, we propose an experimental approach using the cascade...
Research on quantum many-body problems is essential in a wide variety of scientific fields. By reducing the many-body problem formulated in terms of N-body wave functions to the one-body level with the density distributions, the density functional theory (DFT) has been enormously popular. However, the quality of the DFT results crucially depends on the accuracy of the energy density...
With the acceleration of climate change, the increasing frequency of wildfires and earthquakes, recurring energy crises, and the release of contaminated water from the Fukushima nuclear power plant, our societies are confronted with a growing range of natural and human-induced hazards. These circumstances highlight the critical need for educational approaches that foster hazard...
The shell structure and magic numbers are fundamental properties of atomic nuclei, which predict the existence of the island of stability for superheavy nuclei. On one hand, the occurrence of nuclear magic numbers can be theoretically explained by introducing a spin-orbit interaction between nucleons, leading to a breaking of the relevant spin symmetry. On the other hand, the observation of...
The Beam Drift Chamber (BDC) is an important instrument for accurately reconstructing beam trajectories as they approach the experimental target of LAMPS (Large Acceptance Multi-Purpose Spectrometer) at RAON (Rare isotope Accelerator complex for ON-line experiments), in Daejeon, Korea. To assess its performance, focusing on trajectory reconstruction efficiency and position resolution, a...
Ensuring the reliability and efficiency of the muon reconstruction is essential for a vigorous muon-based physics program in heavy-ion collisions at CMS. This poster presents the performance of the CMS muon reconstruction recorded during the LHC run3. The analysis will explore the key aspects, including the muon calibration, tracking, identification, triggering, and momentum resolution, to...
Large-diameter photomultiplier tubes (PMTs) have been widely used in large-scale neutrino experiments. This presentation discusses the characteristics of a 20-inch PMT featuring a box-and-line type dynode structure. Using a picosecond pulse laser, the charge and time response of the PMT was investigated in detail, and the uniformity of the photocathode position was tested. These results...
The $^{34}$Ar($\alpha$,p)$^{37}$K reaction is critical for shaping the light curve and understanding the nucleosynthesis mechanism in X-ray bursts. Notably, it is regarded as one of the primary reactions contributing to the formation of double peaked light curves. So far several experiments have been performed to determine the reaction rate of $^{34}$Ar($\alpha$,p)$^{37}$K; however, a...
Necessity of the three-nucleon forces (3NFs) have come to light in various nuclear phenomena, for example, binding energies of nuclei, and equation of state in nuclear matters. As numerically exact solutions of the Faddeev equations using 2N- and 3N-forces are now attainable for observables in nucleon-deuteron (Nd) scattering, intricate information of the 3NFs can be extracted by directly...
This project is a case of applied education in which teachers and students from six departments—Architecture, Civil Engineering, Electrical Engineering, Electronics, Mechanical Engineering, and Automotive Engineering—collaborated to remodel an unused space on campus into a student lounge. Students conceptualized and designed the space, participated in the construction process, shared technical...
The Rare Isotope Accelerator complex for ON-line experiments (RAON) at the Institute for Rare Isotope Science (IRIS) in Korea produces rare isotopes using an Isotope Separation On-Line (ISOL) facility. The ISOL system consists of a cyclotron, a target ion source (TIS) module system, a pre-mass separator, a rare isotope identification station, an RFQ cooler and buncher (RFQCB), an electron beam...
Neutrino oscillation is a key phenomenon for testing beyond the Standard Model. Due to the weak interaction of neutrinos, large-volume detectors and effective background discrimination are required. Liquid scintillator (LS) is a suitable medium for constructing large-volume detectors. Light produced in LS is generally amplified by photomultiplier tubes (PMTs) and converted into electronic...
In 2023, we have proposed a new theoretical approach that can be used to study hadron spin decomposition based on QCD sum rules. By collecting all responses of quarks and gluons in a rotating frame, we describe the spin-rotation coupling of a hadron in a relativistic formalism. Using this idea, we studied spin contents of spin-1 quarkonia in the previous work. Recently, we applied the same...
KoBRA (KOrea Broad acceptance Recoil spectrometer and Apparatus) [1,2] is a multi-purpose low energy (~1 to 40 MeV/u) nuclear physics facility at IRIS (Institute for Rare Isotope Science) and was successfully completed for beam commissioning in the last two years [3]. In addition to producing RI beams with 40Ar8+ stable ion beams, 25Na beams from the ISOL system were accelerated through SLC3...
The NA61/SHINE at the CERN SPS is a multipurpose fixed-target experiment for charged and neutral hadron measurements. Its research program includes studies of strong interactions as well as reference measurements for neutrino and cosmic-ray physics. The advantage of the NA61/SHINE spectrometer over collider experiments is the coverage of nearly the entire forward hemisphere for charged...
The isovector giant dipole resonance (IVGDR) serves as a crucial tool for probing a wide range of phenomena, from r-process nucleosynthesis to the determination of the strength of gravitational waves. Generally, the width of the IVGDR ($\Gamma_G$) increases with temperature ($T$) in the range of 1 MeV $\lesssim T\lesssim 3$ MeV, with the possibility of saturation at higher temperatures [1]....
I discuss the neutron star equation of state. I demonstrate that the restoration of conformal symmetry requires changing the sign of the curvature of the energy per particle. I argue that the curvature of the energy per particle may serve as an approximate order parameter that signifies the onset of strongly coupled conformal matter in the neutron star core. Lastly, I relate the thermodynamic...
The disappearance of N=28 magicity results in strong quadrupole deformation and shape coexistence in nuclei in this region. Especially in $^{44}$S, theoretical studies indicate large shape fluctuations in the ground state [1, 2]. The one-nucleon knockout reactions can be a useful probe to investigate the ground state configuration. The spectroscopic factors can provide information about the...
Many kinds of density functionals are designed not only to reproduce the basic properties of finite nuclei but also to satisfy the saturation properties of the nuclear matter. Density functional theories (DFT) can describe experimental data in various mass regions. The mean-field calculations using the functionals miss some many-body correlations. Moreover, the odd nuclei are often treated...
This study focuses on simulating the production of beryllium-7 ($^{7}$Be), a radioactive isotope generated in Earth's atmosphere, using Geant4 and the Cosmic Ray Library (CRY), and comparing the results with experimental data. $^{7}$Be is primarily produced when cosmic rays interact with nitrogen nuclei in the atmosphere, and its concentration varies with solar activity and seasonal changes....
Cryogenic detectors are widely used in searches for rare physics processes such as neutrino and dark matter interactions. Lowering the detection energy threshold not only helps better understanding of background but also enriches the physics program of the experiment. A new trigger method has been developed using Pearson correlation coefficient, also known as $r$-value. The new method compares...
The Neutrino Elastic-Scattering Observation with NaI(Tl) (NEON) experiment aims to observe coherent elastic neutrino-nucleus scattering (CEvNS) and extends its scope to include incoherent neutrino-nucleus scattering (IvNS).
The experiment is located at the tendon gallery of the Hanbit Nuclear Power Plant in Yeonggwang, South Korea, and has been successfully operating since 2022 using 6...
The RENE (Reactor Experiment for Neutrinos and Exotics) experiment aims to investigate sterile neutrino oscillation for Δm_41^2 ~ 2 eV^2 region.
The RENE prototype detector will be located in the tendon gallery of the Hanbit Nuclear Power Plant.
The VETO detector will cover the outermost part of the RENE prototype detector to reject background events, mainly coming from cosmic muons. The...
Studies of double beta (2𝜈𝛽𝛽) decay to various excited states in different isotopes provide valuable insights into nuclear structure models. The AMoRE, which utilizes an array of $^{100}$Mo-enriched CaMoO$_{4}$ and Li$_{2}$MoO$_{4}$ crystal scintillators, is advantageous for investigating 2𝜈𝛽𝛽 decay of $^{100}$Mo to the excited states of $^{100}$Ru.
In the AMoRE-I phase, we measured the...
The maximum mass of neutron stars and the central baryonic density corresponding to this maximum are investigated within the relativistic mean field framework. The need for new equations of state (EoS) and theoretical frameworks to describe dense matter physics is requested by recent observations of massive neutron stars (M > 2M_sun). Until recently, Observational data from GW170817 and NICER...
Abstract:
The pairing correlation is essential for understanding low-energy nuclear structure, particularly under varying conditions of temperature and angular momentum.At low temperatures and angular momentum, nucleons near the Fermi surface tend to pair up, leading to strong pairing correlations.However, as temperature (T) or angular momentum (J) increases, these pairing of nucleons is...
Studying particle-hole excitation levels near closed nuclear shells enhances our understanding of single-particle properties and two-body interactions. Although the changes in nuclear of structure doubly magic and near doubly magic nucleus such as $^{4}$He, $^{16}$O, $^{40}$Ca, $^{4}$H, and $^{40}$K are well studied, information on charge-changing particle excitation states in $^{48}$Ca (T=5...
Proton elastic scattering on $^{12}$C is a technique for obtaining detailed information about resonance states and energy levels of $^{13}$N. The interaction between protons and carbon nuclei is also important for ion-beam analysis (IBA) used for light element depth profiling in solids.
Discrepancies have emerged in cross-section data at laboratory scattering angles of $~$150$^o$ and...
Correlated nucleons can form various clusters such as $α$ cluster, which can further give rise to intriguing cluster structures in light nuclei, taking the Hoyle state of $^{12}\rm C$ with a 3-$α$ cluster structure as an example. In recent years, important progress has been made in studying the cluster structure of excited states of light neutron-rich nuclei, such as the molecular resonant...
Necessity of three-nucleon forces (3NFs) has now become known to describe various nuclear phenomena (e.g. biding energy of light nuclei, observables of few-nucleon scattering). On the other hand, the 3NFs, especially the spin dependence, is not yet fully understood. We plan to perform a polarized deuteron–polarized proton ($\vec{d}-\vec{p}$) scattering experiment to measure the spin...
The CMS experiment is designed to search for new physics and detect a broad spectrum of particles and physical phenomena using high-energy proton-proton and heavy-ion collisions at the Large Hadron Collider (LHC) at CERN. in 2023 and 2024, data from the lead-lead (Pb-Pb) collision at theLHC were taken at \sqrt{s_{NN}} = 5.36 TeV. The luminosity recorded by the CMS detector was around 1.7...
The comparison of deuterium abundance observed in selected astronomical site and the computed abundance foreseen by the Big Bang Nucleosynthesis (BBN) theory is a powerful tool to derive the baryon density of universe in the first minutes of Universe. The LUNA collaboration has recently completed the study of the D(p,$\gamma$)$^3$He reaction at BBN energies with unprecedented precision,...
In high-energy heavy-ion collision experiments, a pseudo-rapidity, $\eta$, independent behavior emerges in a two-particle angular correlation in the forward direction over a relatively wide range of $\eta$. This behavior is designated the "Ridge." The Ridge behavior observed during high-energy nucleus-nucleus (AA) collisions, which was adequately explained by elliptic and higher-order flows...
The UNF code calculates fast neutron reaction data of medium heavy nuclei with incident energies from about 1 keV up to 20 MeV. The first version of the UNF code was completed in 1994. The code has been developed continually since that time and has often been used as an evaluation tool for setting up CENDL and for analyzing the measurements of fissile materials. During these years many...
Neutrons play a dominant role in the stellar nucleosynthesis of heavy elements. We review a scheme for the experimental determinations of neutron-induced reaction cross sections using a high-intensity neutron source based on the 18O(p,n)18F reaction with an 18O-water target at SARAF’s upcoming Phase II. The quasi-Maxwellian neutron spectrum with effective thermal energy kT ≈ 5 keV,...
The astrophysical origin for the chemical elements between the first and second $r$-process peaks is a matter of intense debate, with a number of nucleosynthesis processes at explosive stellar environments possibly contributing to their production. Reliable data on the trends of neutron separation energies of neutron-rich isotopes are required to model neutron-capture processes that would...
The fusion/capture cross sections (CSs) of complex nuclei are often described in the literature within two approaches: i) the coupled channels model accounting for structure of the colliding nuclei [1,2] and ii) trajectory models with friction and thermal fluctuations (dissipative effects) [3,4]. The first approach does not account for friction whereas the second one is not able to deal with...
The Isotope Separation On-Line (ISOL) system at the Institute for Rare Isotope Science (IRIS) successfully generated a variety of rare isotopes (RI). A variety of devices are used to verify the RI generated. The produced ions from the Target Ion Source (TIS) are cooled and bunched using the Radio Frequency Quadrupole Cooler Buncher (RFQ CB) to improve the charge breeding efficiency of the...
The diverse structural phenomena in nuclei with few valence protons above Z=50 major shell closure, are interesting to study. In A~120-130 region, the collectivity in the nuclear structures is mainly driven by the valence neutrons, while valence protons promote the single particle excitations. Both the protons and neutrons occupy the same set of orbitals, viz., 2d$_{5/2}$, 1g$_{7/2}$,...
The presence of superfluidity in neutron star interiors can affect the cooling of neutron stars in intricate ways, enhancing certain mechanisms and suppressing others. Model calculations employing realistic nuclear potentials in Bardeen–Cooper–Schrieffer theory generally suggest the development of a 3P2–3F2 pairing gap, and therefore the presence of superfluidity in dense neutron star matter....
The neutron dripline in oxygen isotopes presents a clear challenge and unique opportunity for studies of shell evolution and nuclear structure. The heaviest observed bound isotope of flourine (Z=9) has 22 neutrons, whereas oxygen -- with only one fewer proton, Z=8 -- can only bind 16 neutrons. This striking anomaly is a result of an increase in the spacing between the nu(d3/2) orbital and the...
