Level lifetime and side-feeding time measurements were performed on the excited states of the normally deformed bands of ${}^{83}\mathrm{Y}$ using the Doppler-shift attenuation method (DSAM). The high spin states of ${}^{83}\mathrm{Y}$ were populated using the fusion-evaporation reaction ${}^{58}\mathrm{Ni}({}^{32}\mathrm{S},\alpha 3p){}^{83}\mathrm{Y}$ at 135 MeV. Twenty-two level lifetime and side-feeding times were determined in most of the cases by comparing the line shapes gated with transitions above and below the state under study. Quadrupole moments determined from lifetime measurements are in the range $1.1–3.1$ $e\mathrm{b}$, and are similar to the ones found for some of the neighboring nuclei. The measured side-feeding times were compared with predictions made by simulations carried out with the Gammapace code. The results were in agreement with the experimental values by assuming reduced transition probabilities of the collective transitions in the continuum region, lying in the range $40–80$ W.u. The discrete excited states were studied with paired cranked Nilsson-Strutinsky-Bogoliubov (CNSB) calculations carried out for the first time for an $A\approx 80$ nucleus. Unpaired cranked Nilsson-Strutinsky (CNS) calculations were used to specify configurations and study the band crossings. The measured $|Q_t|$ values show a general agreement with CNSB calculations. Cranked shell model analysis evinced that the smallest quadrupole moment appears at the sharpest band crossing of the bands studied and CNSB calculations show an increase of the deformation thereinafter.

We used the phasotron of the Laboratory of Nuclear Problems at JINR to irradiate isotopically pure ${}^{209}\mathrm{Bi}$ target with 660 MeV protons. Cross sections of the fragment production with mass numbers $24\le A\le 210$ u were measured for the first time using the direct $\gamma$-spectrometry method with a high-resolution HpGe detector. The $\gamma$ lines of the fragments have been identified, and the cross sections determined by the deimos code. The results of the measured nuclide cross section have been parametrized in terms of a three-parameter equation in order to reproduce the real isobaric distribution. Fission and spallation mass yields have been reconstructed on the base of charge distribution of reaction products. The main reaction results have been compared with other experimental data obtained from the proton-induced reaction at 600 MeV as well as with theoretical model calculations using the crisp code.

Recently, the bound and continuum spectrum of ${}^{11}\mathrm{Be}$ has been calculated within the ab initio no-core shell model with continuum (NCSMC) method, with the parity inversion in the ground state successfully reproduced. The continuum spectrum obtained is in agreement with known experimental levels. The S matrix contained in the NCSMC continuum wave functions of the $\mathrm{n}+{}^{10}\mathrm{Be}$ system is used in this work for the first time in a transfer-to-the-continuum (TC) reaction calculation. The TC approach is applied to study the excitation energy spectrum of ${}^{11}\mathrm{Be}$ measured in the ${}^9\mathrm{Be}({}^{18}\mathrm{O},{}^{16}\mathrm{O}){}^{11}\mathrm{Be}$ reaction at 84 MeV. Previously known levels are confirmed and theoretical and experimental evidence for a 9/$2^{+}$ state at $E_x=5.8$ MeV is given, whose configuration is thought to be ${}^{10}\mathrm{Be}\left(2^{+}\right)+\mathrm{n}\left(d_{5/2}\right)$.

We study if commonly used nucleon-nucleon effective interactions, obtained from fitting the properties of cold nuclear matter and of finite nuclei, can properly describe the hot dense nuclear matter produced in intermediate-energy heavy-ion collisions. We use two representative effective interactions, i.e., an improved isospin- and momentum-dependent interaction with its isovector part calibrated by the results from the ab initio nonperturbative self-consistent Green's function (SCGF) approach with chiral forces, and a Skyme-type interaction fitted to the equation of state of cold nuclear matter from chiral effective many-body perturbation theory and the binding energy of finite nuclei. In the mean-field approximation, we evaluate the equation of state and the single-nucleon potential for nuclear matter at finite temperatures and compare them to those from the SCGF approach. We find that the improved isospin- and momentum-dependent interaction reproduces reasonably well the SCGF results due to its weaker momentum dependence of the mean-field potential than in the Skyrme-type interaction. Our study thus indicates that effective interactions with the correct momentum dependence of the mean-filed potential can properly describe the properties of hot dense nuclear matter and are thus suitable for use in transport models to study heavy-ion collisions at intermediate energies.

We measured both the differential cross section (${\sigma }_{p,p^{\prime }}=d^2\sigma /d\mathrm{\Omega }d{E}_x$) and the $\gamma$-ray emission probability [$R_{\gamma }\left(E_x\right)={\sigma }_{p,p^{\prime }\gamma }/{\sigma }_{p,p^{\prime }}$] from the giant resonances excited by ${}^{12}\mathrm{C}(p,p^{\prime })$ reaction at 392 MeV and $0^{\circ }$, using a magnetic spectrometer and an array of NaI(Tl) counters. The absolute value of $R_{\gamma }\left(E_x\right)$ was calibrated by using the well-known $\gamma$-ray emission probability from ${}^{12}\mathrm{C}^{*}(15.11$ MeV, $1^{+},T=1$) and ${}^{16}\mathrm{O}^{*}(6.9$ MeV, $2^{+},T=0$) states within 5% uncertainty. We found that $R_{\gamma }\left(E_x\right)$ starts from zero at $E_x=16$ MeV, increases to a maximum of $53.3\pm 0.4\pm 3.9$% at $E_x=27$ MeV, and then decreases. We also compared the measured values of $R_{\gamma }\left(E_x\right)$ with statistical model calculation based on the Hauser-Feshbach formalism in the energy region $E_x=16–32$ MeV and discussed the features of $\gamma$-ray emission probability quantitatively.

Two-particle correlations have been used extensively to study hydrodynamic flow patterns in heavy-ion collisions. In small collision systems, such as $p+p$ and $p+A$, where particle multiplicities are much smaller than in $A+A$ collisions, nonflow effects from jet correlations, momentum conservation, particle decays, etc. can be significant, even when imposing a large pseudorapidity gap between the particles. A number of techniques to subtract the nonflow contribution in two-particle correlations have been developed by experiments at the CERN Large Hadron Collider (LHC) and then used to measure particle flow in $p+p$ and $p+\mathrm{Pb}$ collisions. Recently, experiments at the BNL Relativistic Heavy Ion Collider (RHIC) have explored the possibility of adopting these techniques for small collision systems at lower energies. In this paper, we test these techniques using Monte Carlo generators pythia and hijing, which do not include any collective flow, and ampt, which does. We find that it is crucial to examine the results of such tests both for correlations integrated over particle transverse momentum $p_T$ and differentially as a function of $p_T$. Our results indicate reasonable nonflow subtraction for $p+p$ collisions at the highest LHC energies, while failing if applied to $p+p$ collisions at RHIC. In the case of $p+\mathrm{Au}$ collisions at RHIC, both hijing and ampt results indicate a substantial over-estimate of nonflow for $p_T\gtrsim \mathrm{GeV}/c$ and hence an underestimate of elliptic flow and overestimate of triangular flow.

Radiative capture reactions play a crucial role in stellar nucleosynthesis but have proved challenging to determine experimentally. In particular, the large uncertainty ($\approx 100\%$) in the measured rate of the ${}^{12}\mathrm{C}(\alpha ,\gamma ){}^{16}\mathrm{O}$ reaction is the largest source of uncertainty in any stellar evolution model. With development of high-current energy-recovery linear accelerators (ERLs) and high-density gas targets, measurement of the ${}^{16}\mathrm{O}(e,e^{\prime }\alpha ){}^{12}\mathrm{C}$ reaction close to threshold using detailed balance allows a new approach to determine the ${}^{12}\mathrm{C}(\alpha ,\gamma ){}^{16}\mathrm{O}$ reaction rate with significantly increased precision ($<20\%$). We present the formalism to relate photo- and electrodisintegration reactions and consider the design of an optimal experiment to deliver increased precision. Once the new ERLs come online, an experiment to validate the approach we propose should be carried out. This approach has broad applicability to radiative capture reactions in astrophysics.

The level scheme of the compound ${}^{153}\mathrm{Sm}$ nucleus formed via the ${}^{152}\mathrm{Sm}(n_{\text{th}},\gamma )$ reaction is studied by using a $\gamma -\gamma$ coincidence spectrometer at Dalat Nuclear Research Institute, Vietnam. All the $\gamma$ cascades, which correspond to the decays from the compound state to 12 final levels of 0 (${\frac{3}{2}}^{+}$), 7.535 (${\frac{5}{2}}^{+}$), 35.844 (${\frac{3}{2}}^{-}$), 90.875 (${\frac{5}{2}}^{-}$), 126.412 (${\frac{1}{2}}^{-}$), 127.298 (${\frac{3}{2}}^{-}$), 182.902 (${\frac{5}{2}}^{-}$), 321.113 (${\frac{3}{2}}^{+}$), 404.129 (${\frac{1}{2}}^{-}$), 405.470 (${\frac{3}{2}}^{-}$), 414.924 (${\frac{1}{2}}^{+}$), and 481.088 (${\frac{3}{2}}^{+}$) keV, have been measured. A total number of 386 cascades corresponding to 576 $\gamma$ transitions has been detected. Among these cascades, 103 primary $\gamma$ transitions together with their corresponding intermediate levels and 299 secondary transitions have been determined. In addition, 29 primary $\gamma$ transitions, 42 intermediate levels, and 8 secondary transitions have been found to be the same as those extracted from the Evaluated Nuclear Structure Data File (ENSDF) data. The remaining 74 primary $\gamma$ transitions, 61 intermediate levels, and 291 secondary transitions are therefore considered as new data. In particular, based on an assumption that most of the transitions are dipole, we have tentatively assigned the unique spin value of $\frac{3}{2}\hslash$ for 53 observed intermediate levels corresponding to the cascades from the compound state to the final levels of 7.535 (${\frac{5}{2}}^{+}$), 90.875 (${\frac{5}{2}}^{-}$), and 182.902 (${\frac{5}{2}}^{-}$) keV, whereas the remaining levels are assigned with the spin values in the range of $[\frac{1}{2},\frac{3}{2}]\hslash$. Moreover, the total and partial (for the spin range of $[\frac{1}{2},\frac{3}{2}]\hslash$) cumulative numbers of levels have been constructed by combining the ENSDF data with the new data obtained in the present experiment. Comparison between these new cumulative curves and those extracted from the nuclear level density (NLD) data, which are obtained using the Oslo method, shows that the maximum excitation energy $E_{\max }$, defined as the energy threshold below which most of the excited levels are observed, is extended to about 1.2 and 1.8 MeV for the total and partial NLD data, respectively. These values of $E_{\max }$ are higher than those obtained by using the present ENSDF data, which are around 1 MeV. The new cumulative curves have also been compared with different phenomenological and microscopic NLD models, and the recent exact pairing plus independent-particle model at finite temperature ($\mathrm{EP}+\mathrm{IPM}$), in which no fitting parameter has been employed, is found to be the best-fit one. The present findings provide updated information on the nuclear level structure and make a step toward the completed level schemes of excited compound nuclei.

Lifetime measurements of the lower excited states in the yrast band of ${}^{167}\mathrm{Lu}$ have been measured using the recoil distance Doppler shift method. The excited nuclear states in ${}^{167}\mathrm{Lu}$ were populated via ${}^{159}\mathrm{Tb}({}^{12}\mathrm{C},4n)$ fusion-evaporation reaction at a beam energy of 74 MeV. In the experiment, the lifetime of states from ${13/2}^{-}\hslash$ to ${29/2}^{-}\hslash$ spins were obtained. From extracted lifetimes, the reduced transition probabilities $\left[B\right(E2\left)\right]$ and transition quadrupole moments $\left(Q_t\right)$ values have been deduced. The large $\left(Q_t\right)$ values obtained in the experiment indicate high deformation for ${}^{167}\mathrm{Lu}$ near ground state, a typical characteristic of the mass region. The almost constant values of experimental $B\left(E2\right)$ reflects the stability of deformed structure of ${}^{167}\mathrm{Lu}$ nucleus in the yrast configuration. The experimental results are compared with the results of the cranked Hartree-Fock-Bogoliubov model based total Routhian surface (TRS) calculations. The experimental values are in better agreement with the TRS calculations at low frequencies than at high frequencies.

Some aspects of description of the Bohr-Weisskopf effect in hyperfine splitting (HFS) of the H- and Li-like ions of ${}^{209}\mathrm{Bi}$ are considered by application of the surface and volume models of the nuclear currents. Extension of these models, used in internal conversion theory, as a description of the HFS allows one to successfully describe the effect, without resorting to the specific difference. This is shown not to be needed at all. Moreover, it turns out to depend even more strongly on the nuclear model than the HFS values themselves. A comparison of the calculated HFS values to the experiment shows a satisfactory agreement. Both models provide an equally good description of the effect. However, they result in different values of the retrieved rms radius of the magnetization distribution over the nuclear volume. Prospects of future research are discussed.

We construct the QCD equation of state at finite chemical potentials including net baryon, electric charge, and strangeness, based on the conserved charge susceptibilities determined from lattice QCD simulations and the equation of state of the hadron resonance gas model. For the application to relativistic heavy-ion collisions we consider the situation of strangeness neutrality and matter with a fixed electric charge-to-baryon ratio, resembling that of heavy nuclei. The importance of finite electric charge and strangeness chemical potentials for particle production in heavy-ion collisions is demonstrated using hydrodynamic simulations.

A six-quasiparticle isomer with $T{}_{1/2}$ = 57(2) ns has been established in the doubly-odd isotope ${}^{200}\mathrm{Tl}$ and its level scheme is significantly extended. Half-lives of previously reported isomers in ${}^{200}\mathrm{Tl}$ and ${}^{201,202}\mathrm{Pb}$ have been determined and revised values are reported in a few cases, with $T{}_{1/2}$ = 397(17) ns and 7.0(5) ns for the ${\mathit{I}}^{\pi }=5^{+}$ and $7^{-}$ states in ${}^{200}\mathrm{Tl}$, 52(2) ns for the $41/2^{+}$ level in ${}^{201}\mathrm{Pb}$, and 93(4) ns for the ${16}^{+}$ state in ${}^{202}\mathrm{Pb}$. Configurations for the isomers have been assigned and these predominantly involve intrinsic excitations of neutrons from the $i_{13/2}$ subshell. The inferred transition rates for the decay of these isomers compare well with single-particle estimates attesting to their intrinsic character.

In this paper we demonstrate that a simple nucleon-pair picture, previously investigated for semi-magic even-even nuclei, survives in both odd-mass semi-magic nuclei and a few neutron-rich open-shell nuclei. This is exemplified by low-lying states of the semi-magic nuclei ${}^{43-48}\mathrm{Ca}$ and three open-shell nuclei ${}^{132}\mathrm{Cd}$, ${}^{131}\mathrm{Ag}$, and ${}^{130}\mathrm{Pd}$, calculated with effective interactions. Not only the generalized-seniority-zero, -one and -two states, but also states with larger seniority numbers are shown to be well represented by one-dimensional nucleon-pair wave functions. Very interestingly, such one-dimensional nucleon-pair wave functions are readily adopted to be those with the lowest expectation energies among all nucleon-pair basis states. This provides us with a simple approach to study yrast states of semi-magic nuclei as well as yrast states of open-shell nuclei with only a few valence nucleons.

Background: The even cadmium isotopes near the neutron midshell have long been considered among the best examples of vibrational nuclei. However, the vibrational nature of these nuclei has been questioned based on $E2$ transition rates that are not consistent with vibrational excitations. In the neighboring odd-mass nuclei, the $g$ factors of the low-excitation collective states have been shown to be more consistent with a deformed rotational core than a vibrational core. Moving beyond the comparison of vibrational versus rotational models, recent advances in computational power have made shell-model calculations feasible for Cd isotopes. These calculations may give insights into the emergence and nature of collectivity in the Cd isotopes.

Purpose: To investigate the nature of collective excitations in the $A\approx 100$ region through experimental and theoretical studies of magnetic moments and electromagnetic transitions in ${}^{111}\mathrm{Cd}$.

Method: The spectroscopy of ${}^{111}\mathrm{Cd}$ has been studied following Coulomb excitation. Angular correlation measurements, transient-field $g$-factor measurements and lifetime measurements by the Doppler-broadened line shape method were performed. The structure of the nucleus was explored in relation to particle-vibration versus particle-rotor interpretations. Large-scale shell-model calculations were performed with the SR88MHJM Hamiltonian.

Results: Excited-state $g$ factors have been measured, spin assignments examined, and lifetimes determined. Attention was given to the reported $5/2^{+}$ 753-keV and $3/2^{+}$ 755-keV states. The $3/2^{+}$ 755-keV level was not observed; evidence is presented that the reported $3/2^{+}$ state was a misidentification of the $5/2^{+}$ 753-keV state.

Conclusions: It is shown that the $g$ factors and level structure of ${}^{111}\mathrm{Cd}$ are not readily explained by the particle-vibration model. A particle-rotor approach has both successes and limitations. The shell-model approach successfully reproduces much of the known low-excitation structure in ${}^{111}\mathrm{Cd}$.

The transitional nuclei ${}^{134}\mathrm{Ba}$ and ${}^{133}\mathrm{Ba}$ are investigated after multinucleon transfer employing the high-resolution Advanced GAmma Tracking Array coupled to the magnetic spectrometer PRISMA at the Laboratori Nazionali di Legnaro, Italy, and after fusion-evaporation reaction at the FN tandem accelerator of the University of Cologne, Germany. The $J^{\pi }=19/2^{+}$ state at 1942 keV in ${}^{133}\mathrm{Ba}$ is identified as an isomer with a half-life of $66.6\left(20\right)\mathrm{ns}$ corresponding to a $B\left(E1\right)$ value of $7.7\left(4\right)\times {10}^{-6}{e}^2{\mathrm{fm}}^2$ for the $J^{\pi }=19/2^{+}$ to $J^{\pi }=19/2^{-}$ transition. The level scheme of ${}^{134}\mathrm{Ba}$ above the $J^{\pi }={10}^{+}$ isomer is extended to approximately 6 MeV. A pronounced backbending is observed at $\hslash \omega =0.38$ MeV along the positive-parity yrast band. The results are compared to the high-spin systematics of the $Z=56$ isotopes. Large-scale shell-model calculations employing the GCN50:82, SN100PN, SNV, PQM130, Realistic SM, and EPQQM interactions reproduce the experimental findings and elucidate the structure of the high-spin states. The shell-model calculations employing the GCN50:82 and PQM130 interactions reproduce alignment properties and provide detailed insight into the microscopic origin of this phenomenon in transitional ${}^{134}\mathrm{Ba}$.

The level structure of the odd-odd iodine nucleus ${}^{122}\mathrm{I}$ has been studied by the ${}^{120}\mathrm{Sn}$ (${}^7\mathrm{Li}$, $5n){}^{122}\mathrm{I}$ reaction at $E_{\mathrm{lab}}=58$ MeV. Two chopped beams from the 14UD (Unit Doubled) tandem heavy-ion accelerator at the Australian National University were used; one was a nanosecond (ns) pulsed-beam with separation of 1.7 microseconds ($\mu \mathrm{s}$) and the second one was a $60\text{−}\mu \mathrm{s}$ beam separated by $880\mu \mathrm{s}$. Through in-beam and out-of-beam $\gamma$-ray spectroscopy, the complex proton-neutron multiplet states, including isomers with half-lives of a few tens of ns to a few tens of $\mu \mathrm{s}$, have been identified. Collective states based on the proton $h_{11/2}$ orbital exhibit two kinds of structure depending upon the coupled neutron orbital: a quadrupole vibration when involving the $h_{11/2}$ orbital and a $\gamma$-soft deformed rotation when involving the $g_{7/2}$ orbital. With spherical shell model and deformed shell-model calculations, the observed level structures are explained.

Background: A transparent approach for the study of nuclear shapes and sizes in excited states requires knowledge about dynamic deformations of both neutron and proton distributions, by means of their independent excitations at the same energy. Heavy-ion scattering could be a reliable approach, facilitating a simultaneous study of deformations of charge and matter densities in nuclei.

Purpose: Measurement of angular distributions of the inelastic scattering cross sections for excitations to low-lying $2_1^{+}$ and $3_1^{-}$ states in ${}^{112,116,118,120,122,124}\mathrm{Sn}$ nuclei using ${}^{12}\mathrm{C}$ beam as a probe at $E_{\mathrm{lab}}=60\mathrm{MeV}$, and determination of neutron and proton transition matrix elements involved in each excitation.

Methods: Projectilelike fragments have been detected using ten sets of Si-surface barrier detector telescopes to measure the cross sections for elastic and inelastic scattering channels. Coupled reaction channels calculations are performed to understand the measured differential cross sections.

Results: Homogeneous nature of surface vibrations (similar deformation for proton and neutron distributions) for the $2_1^{+}$ and $3_1^{-}$ states in Sn isotopes is observed.

Conclusions: A comparison with recent results using ${}^7\mathrm{Li}$ projectile at similar $E_{\mathrm{c}.\mathrm{m}.}/V_{\mathrm{B}}$, which showed damped neutron vibrations particularly for the $3_1^{-}$ state, confirms that such measurements are probe dependent. Intrinsic transition matrix elements of nuclei can be deduced by removing the effects of finite projectile size in the extraction of nuclear shapes.

The respective contributions of cold-matter and hot-medium effects to the suppression of $\mathrm{{\rm Y}}\left(1\mathrm{S}\right)$ and $\mathrm{{\rm Y}}\left(2\mathrm{S}\right)$ mesons in $p\mathrm{Pb}$ collisions at energies reached at the CERN Large Hadron Collider (LHC) are investigated. Whereas known alterations of the parton density functions in the lead nucleus and coherent parton energy loss account for the leading fraction of the modifications in cold nuclear matter (CNM), the hot-medium (quark-gluon plasma, QGP) effects turn out to be relevant in spite of the small initial spatial extent of the fireball. We compare our transverse-momentum-, rapidity-, and centrality-dependent theoretical results for the $\mathrm{{\rm Y}}$ suppression in $p\mathrm{Pb}$ collisions at a center-of-mass energy of $\sqrt{s_{NN}}=8.16\mathrm{TeV}$ with recent LHCb and preliminary ALICE data from the LHC. Both cold-matter and hot-medium effects are needed to account for the data. The initial central temperature of the fireball is found to be $T_0\simeq 460\mathrm{MeV}$, but depends on the bottomonium formation time.

Properties of the baryon-baryon interactions in the strangeness $S=-2$ sector of chiral effective field theory at the next-to-leading order (NLO) level are explored by calculating $\mathrm{\Xi }$ single-particle potentials in symmetric nuclear matter. The results are transformed to the $\mathrm{\Xi }$ potential in finite nuclei by a local-density approximation with convolution by a Gaussian form factor to simulate finite-range effects. The $\mathrm{\Xi }$ potential is repulsive in a central region, and attractive in a surface area when the $\mathrm{\Xi }$ energy is low. The attractive pocket can lower the ${\mathrm{\Xi }}^{-} s$ and $p$ atomic states. The obtained binding energies in ${}^{12}\mathrm{C}$ and ${}^{14}\mathrm{N}$ are found to be conformable with those found in emulsion experiments at Japan's National Laboratory for High Energy Physics (KEK). $K^{+}$ spectra of $(K^{-},K^{+}) \mathrm{\Xi }$ production inclusive processes on ${}^9\mathrm{Be}$ and ${}^{12}\mathrm{C}$ are also evaluated, using a semiclassical distorted wave method. The absolute values of the cross section are properly reproduced for ${}^9\mathrm{Be}$, but the peak locates at a lower energy position than that of the experimental data. The calculated spectrum of ${}^{12}\mathrm{C}$ should be compared with the forthcoming result from the new experiments recently carried out at KEK with better resolution than before. The comparison would be valuable to improve the understanding of the $\mathrm{\Xi }N$ interaction, the parametrization of which has still large uncertainties.

One new pair of positive-parity chiral doublet bands have been identified in the odd-$A$ nucleus ${}^{135}\mathrm{Nd}$ which together with the previously reported negative-parity chiral doublet bands constitute a third case of multiple chiral doublet ($\mathrm{M}\chi \mathrm{D}$) bands in the $A\approx 130$ mass region. The properties of the $\mathrm{M}\chi \mathrm{D}$ bands are well reproduced by constrained covariant density functional theory and particle rotor model calculations. The newly observed $\mathrm{M}\chi \mathrm{D}$ bands in ${}^{135}\mathrm{Nd}$ represents an important milestone in supporting the existence of $\mathrm{M}\chi \mathrm{D}$ in nuclei.