A simultaneous blast-wave fit to particle yields and elliptic flow ($v_2$) measured as a function of transverse momentum in Pb-Pb collisions at energies available at the Large Hadron Collider (LHC) is presented. A compact formula for the calculation of $v_2\left(p_{\mathrm{T}}\right)$ for an elliptic freeze-out surface is used which follows from the Cooper-Frye ansatz without further assumptions. Over the full available $p_{\mathrm{T}}$ range, the $\mathrm{{\rm Y}}$ elliptic flow data is described by the prediction based on the fit to lighter particles. This prediction shows that, due to the large $\mathrm{{\rm Y}}$ mass, a sizable elliptic flow is only expected at transverse momenta above $10\mathrm{GeV}/c$.

We study low-energy dipole excitations in the unstable nucleus ${}^{68}\mathrm{Ni}$ with the beyond-mean-field (BMF) subtracted second random-phase approximation (SSRPA) model based on Skyrme interactions. First, strength distributions are compared with available experimental data and transition densities of some selected peaks are analyzed. The so-called isospin splitting is also discussed by studying the isoscalar-isovector character of such excitations. We estimate then in an indirect way BMF effects on the symmetry energy of infinite matter and on its slope, starting from the BMF SSRPA low-lying strength distribution. For this, several linear correlations are used, the first one being a correlation existing between the contribution (associated with the low-energy strength) to the total energy-weighted sum rule (EWSR) and the slope of the symmetry energy. BMF estimates for the slope of the symmetry energy can be extracted in this way. Correlations between such a slope and the neutron-skin thickness of ${}^{68}\mathrm{Ni}$ and correlations between the neutron-skin thickness of ${}^{68}\mathrm{Ni}$ and the electric-dipole polarizability times the symmetry energy are then used to deduce BMF effects on the symmetry energy.

We derive the values of nuclear symmetry energy, its components, as well as pressure in finite nuclei at saturation density from their corresponding values in nuclear matter obtained in nonrelativistic Brueckner-Hartree-Fock calculations with the realistic Bonn B and Bonn CD potentials using the coherent density fluctuation model in the framework of a self-consistent Skyrme-Hartree-Fock plus BCS method. We focus on three isotopic chains of spherical nuclei (Ni, Sn, and Pb) and compare our results with those obtained with an effective Brueckner density-dependent potential. The role of the three-body forces on the considered quantities is also studied and discussed.

A new transport code “DaeJeon Boltzmann-Uehling-Uhlenbeck” (DJBUU) has been developed and enables us to describe the dynamics of heavy-ion collisions in the low-energy region. To confirm the validity of the new code, we first calculate $\text{Au}+\text{Au}$ collisions at $E_{\mathrm{beam}}=100A$ and $400A\mathrm{MeV}$ and also perform the box calculation to check the detail of collisions and Pauli blocking without using a mean-field potential as suggested by the Transport Code Comparison Project. After confirming the validity of new transport code, we study low-energy heavy-ion collisions by using an extended parity doublet model. Since the distinctive feature of the parity doublet model is the existence of the chiral-invariant mass that contributes to the nucleon mass, we investigate how physical quantities depend on the chiral-invariant mass in heavy-ion collisions at low energies. For this, we calculate physical quantities such as the effective nucleon mass in central collisions and transverse flow in semicentral collisions of $\text{Au}+\text{Au}$ at $E_{\mathrm{beam}}=400A\mathrm{MeV}$ with different values of the chiral-invariant masses.

We investigate the evolution of clustering structure through the momentum distributions in the ${}^{8\text{–}10}\mathrm{Be}$ isotopes. The nucleon dynamics within the intercluster antisymmetrization are discussed via the momentum distribution of a Brink type $\alpha \text{−}\alpha$ wave function. For the state with a small $\alpha \text{−}\alpha$ distance, we observe a significant depression with a dip structure at zero momentum and an enhanced tail in a relatively higher momentum region. In addition, we find the “cluster structure” in the intrinsic frame of momentum space, which is complementary to its significant $\alpha$-cluster dissolution in the coordinate space because of the strong antisymmetrization. For the physical ${}^{8\text{–}10}\mathrm{Be}$ isotopes, the Tohsaki-Horiuchi-Schuck-Röpke (THSR) wave functions are adopted. The evolution from the dilute clustering state to the compact one is demonstrated by a successive depression at zero momentum of nucleon distribution for the two $\alpha$ clusters within ${}^{8\text{–}10}\mathrm{Be}$ isotopes. For the compact ${}^{10}\mathrm{Be}$ nucleus, the momentum distribution of all nucleons shows significant depression at zero momentum with a dip structure, which is found to be contributed by both the intercluster antisymmetrization and the $p$-orbit occupation of the valence neutrons. This study proposes a new window for the investigations of the $\alpha$-clustering effects via the low-momentum components of nuclei, which is expected to be extended to the heavier nuclear clustering states.

The $K^{\pi }=0_1^{+}$, $K^{\pi }=2^{-}$, and $K^{\pi }=0_1^{-}$ bands of ${}^{20}\mathrm{Ne}$ are investigated with microscopic structure and reaction calculations via proton and $\alpha$ inelastic scattering off ${}^{20}\mathrm{Ne}$. Structures of ${}^{20}\mathrm{Ne}$ are calculated with variation after parity and total angular momentum projections in the antisymmetrized molecular dynamics (AMD). The $K^{\pi }=0_1^{+}$ and $K^{\pi }=0_1^{-}$ bands have ${}^{16}\mathrm{O}+\alpha$ cluster structures, whereas the $K^{\pi }=2^{-}$ band shows a ${}^{12}\mathrm{C}+2\alpha$-like structure. Microscopic coupled-channel calculations of proton and $\alpha$ scattering off ${}^{20}\mathrm{Ne}$ are performed by using the proton-nucleus and $\alpha$-nucleus potentials, which are derived by folding the Melbourne $g$-matrix $NN$ interaction with AMD densities of ${}^{20}\mathrm{Ne}$. The calculation reasonably reproduces the observed cross sections of proton scattering at $E_p=25$–35 MeV and $\alpha$ scattering at $E_{\alpha }=104$–386 MeV. Transition properties from the ground to excited states are discussed by reaction analyses of proton and $\alpha$ inelastic processes. Mixing of the $K^{\pi }=2^{-}$ and $K^{\pi }=0_1^{-}$ bands is discussed by detailed analysis of the $0_1^{+}\to 3_1^{-}$ and $0_1^{+}\to 3_2^{-}$ transitions. For the $3_1^{-}$ state, mixing of the $K^{\pi }=0_1^{-}$ cluster component in the $K^{\pi }=2^{-}$ band plays an important role in the transition properties.

Background: The quadratic isobaric multiplet mass equation (IMME) has been very successful at predicting the masses of isobaric analog states in the same multiplet, while its coefficients are known to follow specific trends as functions of mass number. The Atomic Mass Evaluation 2016 [Chin. Phys. C 41, 030003 (2017)] ${}^{44}\mathrm{V}$ mass value results in an anomalous negative $c$ coefficient for the IMME quadratic term; a consequence of large uncertainty and an unresolved isomeric state. The $b$ and $c$ coefficients can provide useful constraints for construction of the isospin-nonconserving Hamiltonians for the $pf$ shell. In addition, the excitation energy of the $0^{+},T=2$ level in ${}^{44}\mathrm{V}$ is currently unknown. This state can be used to constrain the mass of the more exotic ${}^{44}\mathrm{Cr}$.

Purpose: The aim of the experimental campaign was to perform high-precision mass measurements to resolve the difference between ${}^{44}\mathrm{V}$ isomeric and ground states, to test the IMME using the new ground state mass value and to provide necessary ingredients for the future identification of the $0^{+}$, $T=2$ state in ${}^{44}\mathrm{V}$.

Method: High-precision Penning trap mass spectrometry was performed at LEBIT, located at the National Superconducting Cyclotron Laboratory, to measure the cyclotron frequency ratios of [${{}^{44g,m}\mathrm{VO}]}^{+}$ versus [${{}^{32}\mathrm{SCO}]}^{+}$, a well-known reference mass, to extract both the isomeric and ground state masses of ${}^{44}\mathrm{V}$.

Results: The mass excess of the ground and isomeric states in ${}^{44}\mathrm{V}$ were measured to be $-23804.9\left(80\right)$ keV/$c^2$ and $-23537.0\left(55\right)$ keV/$c^2$, respectively. This yielded a new proton separation energy of $S_p=1773\left(10\right)$ keV.

Conclusion: The new values of the ground state and isomeric state masses of ${}^{44}\mathrm{V}$ have been used to deduce the IMME $b$ and $c$ coefficients of the lowest $2^{+}$ and $6^{+}$ triplets in $A=44$. The $2^{+}c$ coefficient is now verified with the IMME trend for lowest multiplets and is in good agreement with the shell-model predictions using charge-dependent Hamiltonians. The mirror energy differences were determined between ${}^{44}\mathrm{V}$ and ${}^{44}\mathrm{Sc}$, in line with isospin-symmetry for this multiplet. The new value of the proton separation energy determined, to an uncertainty of 10 keV, will be important for the determination of the $0^{+}$, $T=2$ state in ${}^{44}\mathrm{V}$ and, consequently, for prediction of the mass excess of ${}^{44}\mathrm{Cr}$.

The composition of hot and dense nuclear matter is calculated including the $1p$-shell nuclei $4\le A\le 16$. In-medium shifts, in particular Pauli blocking, are determined by the intrinsic wave function of the nuclei. Results are given within a shell-model approach for the nucleon wave function. Light nuclei are not always well described by the shell model. The “clustered” nucleus ${}^8\mathrm{Be}$ exhibits strong correlation effects because of $\alpha$-like clustering. Intrinsic cluster structures are also significant for the nuclei ${}^6\mathrm{Li}$, ${}^7\mathrm{Li}$, ${}^7\mathrm{Be}$, and ${}^9\mathrm{Be}$. The contribution of the relatively rare elements Li, Be, and B, to the equation of state (EoS) of matter near the saturation density is overestimated in simple approaches such as the nuclear statistical equilibrium (NSE) model. Both the treatment of continuum correlations and the account of in-medium modifications are considered for the contribution of ${}^5\mathrm{He}$ and ${}^4\mathrm{H}$ clusters. Compared to the extended NSE including unstable nuclei, the contributions of the corresponding $P_{3/2}$ channel with $A=5,Z=2$ and $P_2$ channel with $A=4,Z=1$, respectively, to the EoS are strongly suppressed at high densities owing to Pauli blocking effects. For the shifts of the binding energies of the light $p$-shell nuclei, simple-fit formula are given to calculate the composition of hot and dense matter in a wide parameter range.

The electromagnetic effects of the finite size of the nucleon are implemented self-consistently on top of the Skyrme Hartree-Fock calculation, where the electric form factors of both protons and neutrons are considered. Furthermore, the vacuum polarization and the electromagnetic spin-orbit interaction are taken into account. The self-consistent finite-size effects give a different Coulomb potential from the conventional one and affect the neutrons as well. The contribution of the finite-size effects to the total energy reaches $7\mathrm{MeV}$ in ${}^{208}\mathrm{Pb}$. The vacuum polarization and the electromagnetic spin-orbit interaction are also non-negligible, especially in the heavy nuclei. These effects provide a comparable contribution of the total energy to that of the isospin symmetry-breaking terms of the nuclear interaction. The mirror nuclei mass difference in ${}^{48}\mathrm{Ca}\text{–}{}^{48}\mathrm{Ni}$ is also studied, and its value is improved by approximately one order of magnitude.

Two new USD-type Hamiltonians, USDC and USDI, have been developed that directly incorporate Coulomb and other isospin-breaking interactions. Starting from ab initio interactions, linear combinations of two-body matrix elements were constrained by experimental energy levels in sd-shell nuclei. With this method, binding energies and excitation energies of proton-rich nuclei in the shell can be added to the data set used in the fit. USDC is based on the same renormalized $G$ matrix used in the derivation of previous USD-type Hamiltonians, while USDI is derived from in-medium similarity renormalization group (IMSRG) interactions. Both contain an analytic Coulomb interaction with Miller-Spencer short-range correlations and an effective isotensor interaction. Also presented are modifications to these interactions, USDCm and USDIm, that have had the Coulomb interaction constrained to better reproduce the experimental $b$ coefficients of the isobaric mass multiplet equation. These Hamiltonians are used to provide new predictions for the proton-dripline and to examine isospin-level mixing and other properties of $sd$-shell nuclei. An empirical expression for the Thomas-Ehrman shift in loosely bound and unbound proton-rich states is presented, and several such states are examined.

The low-lying non-yrast states in ${}^{114}\mathrm{Te}$ have been investigated using the Indian National Gamma Array through the fusion-evaporation reaction ${}^{112}\mathrm{Sn}({}^4\mathrm{He},2n)$ at a beam energy of 37 MeV. Eight new $\gamma$ transitions have been placed in the level scheme to establish the quasi-$\gamma$ band in this nucleus. Spin and parity of several excited states have been assigned from the present spectroscopy measurements. The comparison of experimental results on the observed bands with the interacting boson model (IBM) and triaxial projected shell model (TPSM) confirms the existence of the quasi-$\gamma$ band structure in the ${}^{114}\mathrm{Te}$ nucleus.

The ${}^{11}\mathrm{Li}+p$ and ${}^{11}\mathrm{Li}+d$ reactions are investigated in the continuum discretized coupled channel (CDCC) method with a three-body description (${}^9\mathrm{Li}+n+n$) of ${}^{11}\mathrm{Li}$. I first discuss the properties of ${}^{11}\mathrm{Li}$, and focus on $E1$ transition probabilities to the continuum. The existence of a $1^{-}$ resonance at low excitation energies is confirmed, but the associated $E1$ transition from the ground state does not have an isoscalar character, as suggested in a recent experiment. In a second step, I study the ${}^{11}\mathrm{Li}+p$ elastic cross section at $E_{\mathrm{lab}}=66$ MeV in the CDCC framework. I obtain a fair agreement with experiment, and show that breakup effects are maximal at large angles. The breakup cross section is shown to be dominated by the $1^{-}$ dipole state in ${}^{11}\mathrm{Li}$, but the role of this resonance is minor in elastic scattering. From CDCC equivalent ${}^{11}\mathrm{Li}+p$ and ${}^{11}\mathrm{Li}+n$ potentials, I explore the ${}^{11}\mathrm{Li}+d$ cross section within a standard three-body ${}^{11}\mathrm{Li}+(p+n)$ model. At small angles, the experimental cross section is close to the Rutherford scattering cross section, which is not supported by the CDCC. A five-body $({}^9\mathrm{Li}+n+n)+(p+n)$ calculation is then performed. Including breakup states in ${}^{11}\mathrm{Li}$ and in the deuteron represents a numerical challenge for theory, owing to the large number of channels. Although a full convergence could not be reached, the CDCC model tends to overestimate the data at small angles. I suggest that measurements of the ${}^9\mathrm{Li}+p$ elastic scattering would be helpful to determine more accurate optical potentials. The current disagreement between experiment and theory on ${}^{11}\mathrm{Li}+d$ scattering also deserves new experiments at other energies.

We formulate microscopic neutron-nucleus optical potentials from many-body perturbation theory based on chiral two- and three-body forces. The neutron self-energy is first calculated in homogeneous matter to second order in perturbation theory, which gives the central real and imaginary terms of the optical potential. The real spin-orbit term is calculated separately from the density matrix expansion using the same chiral interaction as in the self-energy. Finally, the full neutron-nucleus optical potential is derived within the improved local density approximation utilizing mean-field models consistent with the chiral nuclear force employed. We compare the results of the microscopic calculations to phenomenological models and experimental data up to projectile energies of $E=200\mathrm{MeV}$. Experimental elastic differential scattering cross sections and vector analyzing powers are generally well reproduced by the chiral optical potential, but we find that total cross sections are overestimated at high energies.

Liquid xenon (LXe) is employed in a number of current and future detectors for rare event searches. We use the EXO-200 experimental data to measure the absolute scintillation and ionization yields generated by $\gamma$ interactions from ${}^{228}\mathrm{Th}$ (2615 keV), ${}^{226}\mathrm{Ra}$ (1764 keV), and ${}^{60}\mathrm{Co}$ (1332 keV and 1173 keV) calibration sources, over a range of electric fields. The $W$ value that defines the recombination-independent energy scale is measured to be $11.5\pm 0.5$ (syst.) $\pm 0.1$ (stat.) eV. These data are also used to measure the recombination fluctuations in the number of electrons and photons produced by the calibration sources at the MeV scale, which deviate from extrapolations of lower-energy data. Additionally, a semiempirical model for the energy resolution of the detector is developed, which is used to constrain the recombination efficiency, i.e., the fraction of recombined electrons that result in the emission of a detectable photon. Detailed measurements of the absolute charge and light yields for MeV-scale electron recoils are important for predicting the performance of future neutrinoless double $\beta$-decay detectors.

The framework of the random-phase approximation (RPA) based on the relativistic Hartree-Fock (RHF) theory is extended to achieve a self-consistent calculation with the $\rho$-meson tensor coupling. The model self-consistency is verified by the check of the isobaric analog state, and it is found that the $\rho$-tensor and $\rho$-vector-tensor couplings play significant roles in maintaining the self-consistency. Using the RHF Lagrangian PKA1, the properties of the Gamow-Teller resonances (GTR) are investigated, in which the roles played by the particle-hole residual interaction of various meson-nucleon couplings are clarified in details. Furthermore, the effects of the tensor force, which is introduced naturally via the Fock terms, are analyzed by comparing the calculations with full Lagrangians and the ones artificially dropping the tensor force components. It is found that for the RHF Lagrangians $\mathrm{PKO}i$ $(i=1,2,3)$ and PKA1, the tensor forces play the role mainly via the RHF mean field rather than via the RPA residual interaction in determining the GTR. Moreover, the tensor-force effects are not as strong as those indicated by the Skyrme Hartree-Fock calculations.

Theoretical half-lives of $\alpha$ decay for lead (Pb) isotopes $(Z=82)$ in the range $178\le A\le 220$ systematically have been investigated within the modified generalized liquid drop model (MGLDM). Akrawy, Royer, AKRE, and Modified RenB formulas are used to evaluate $\alpha$-decay half-lives. The experimental $Q$ values are used. The results are compared with the experimental data and with Coulomb and proximity potential model. The standard deviations are evaluated; the results indicate that the MGLDM and Akrawy are the best model and formula for evaluating $\alpha$ decay for Pb isotopes.

Background: Nuclear radius is one of the most important and basic properties of atomic nuclei and its evolution is closely related to the saturation of the nuclear density in the internal region but the systematics of the nuclear radii for the neutron-rich unstable nuclei is not well known.

Purpose: Motivated by the recent interaction cross section measurement which indicates the ${}^{48}\mathrm{Ca}$ core swelling in the neutron-rich Ca isotopes, we explore the mechanism of the enhancement of the neutron and proton radii for spherical nuclei.

Methods: Microscopic Hartree-Fock calculations with three sets of Skyrme-type effective interactions are performed for the neutron-rich Ca, Ni, and Sn isotopes. The total reaction cross sections for the Ca isotopes are evaluated with the Glauber model to compare them with the recent cross section data.

Results: We obtain good agreement with the measured cross sections and charge radii. The neutron and proton radii of the various “core” configurations are extracted from the full Hartree-Fock calculation and discuss the core swelling mechanism.

Conclusions: The core swelling phenomena occur depending on the properties of the occupying valence single-neutron states to minimize the energy loss that comes from the saturation of the densities in the internal region, which appears to be prominent in light nuclei such as Ca isotopes.