We studied dipole excitations in ${}^{10}\mathrm{Be}$ based on an extended version of the antisymmetrized molecular dynamics, which can describe 1p-1h excitations and large amplitude cluster modes. Toroidal and compressive dipole operators are found to be good proves to separate the low-energy and high-energy parts of the isoscalar dipole excitations, respectively. Two low-energy $1^{-}$ states, the toroidal dominant $1_1^{-}$ state at $E\sim 8$ MeV and the $E1$ dominant $1_2^{-}$ state at $E\sim 16$ MeV, were obtained. By analysis of transition current densities, the $1_1^{-}$ state is understood as a toroidal dipole mode with exotic toroidal neutron flow caused by rotation of a deformed ${}^6\mathrm{He}$ cluster, whereas the $1_2^{-}$ state is regarded as a neutron-skin oscillation mode, which are characterized by surface neutron flow with inner isoscalar flow caused by the surface neutron oscillation against the $2\alpha$ core.

The high-spin states in ${}^{133}\mathrm{Cs}$, populated using the reaction ${}^{130}\mathrm{Te}({}^7\mathrm{Li},4n)$ with 45-MeV beam energy, have been extended up to an excitation energy of 5.265 MeV using the Indian National Gamma Array. The observed one- and three-quasiparticle bands in ${}^{133}\mathrm{Cs}$, built on the $\pi h_{11/2},\pi g_{7/2}$, $\pi d_{5/2}$; and ${\left(\pi g_{7/2}\pi d_{5/2}\right)}^1\otimes \nu h_{11/2}^{-2}$ configurations, respectively, have similar structure as seen in the lighter odd-$A$ Cs isotopes. The experimental level scheme has been compared with the large-scale shell model calculation without truncation using the $jj55pna$ interaction, showing a good agreement for both positive- and negative-parity states.

The neutron-rich nucleus ${}^{200}\mathrm{Pt}$ is investigated via in-beam $\gamma$-ray spectroscopy to study the shape evolution in the neutron-rich platinum isotopes towards the $N=126$ shell closure. The two-neutron transfer reaction ${}^{198}\mathrm{Pt}$(${}^{82}\mathrm{Se}, {}^{80}\mathrm{Se}$)${}^{200}\mathrm{Pt}$ is used to populate excited states of ${}^{200}\mathrm{Pt}$. The Advanced Gamma Ray Tracking Array (AGATA) demonstrator coupled with the PRISMA spectrometer detects $\gamma$ rays coincident with the ${}^{80}\mathrm{Se}$ recoils, the binary partner of ${}^{200}\mathrm{Pt}$. The binary partner method is applied to extract the $\gamma$-ray transitions and build the level scheme of ${}^{200}\mathrm{Pt}$. The level at 1884 keV reported by Yates et al. [S. W. Yates, E. M. Baum, E. A. Henry, L. G. Mann, N. Roy, A. Aprahamian, R. A. Meyer, and R. Estep, Phys. Rev. C 37, 1889 (1988)] was confirmed to be at 1882.1 keV and assigned as the $\left(6_1^{+}\right)$ state. An additional $\gamma$ ray was found and it presumably deexcites the $\left(8_1^{+}\right)$ state. The results are compared with state-of-the-art beyond mean-field calculations, performed for the even-even ${}^{190-204}\text{Pt}$ isotopes, revealing that ${}^{200}\mathrm{Pt}$ marks the transition from the $\gamma$-unstable behavior of lighter Pt nuclei towards a more spherical one when approaching the $N=126$ shell closure.

For the first time, we apply the temperature-dependent relativistic mean-field (TRMF) model to study the ternary fragmentation of heavy nuclei using the level density approach. The relative fragmentation probability of a particular fragment is obtained by evaluating the convolution integrals that employ the excitation energy and the level density parameter for a given temperature calculated within the TRMF formalism. To illustrate, we have considered the ternary fragmentations in ${}^{252}\mathrm{Cf}, {}^{242}\mathrm{Pu}$, and ${}^{236}\mathrm{U}$ with a fixed third fragment $A_3={}^{48}\mathrm{Ca}, {}^{20}\mathrm{O}$, and ${}^{16}\mathrm{O}$, respectively. The relative fragmentation probabilities are studied for the temperatures $T=1$, 2, and 3 MeV. For the comparison, the relative fragmentation probabilities are also calculated from the single-particle energies of the finite range droplet model (FRDM). In general, the larger phase space for the ternary fragmentation is observed indicating that such fragmentations are most probable ones. For $T=2$ and 3 MeV, $\mathrm{Sn}+\mathrm{Ni}+\mathrm{Ca}$ is the most probable combination for the nucleus ${}^{252}\mathrm{Cf}$. However, for the nuclei ${}^{242}\mathrm{Pu}$ and ${}^{236}\mathrm{U}$, the maximum fragmentation probabilities at $T=2$ MeV differ from those at $T=3$ MeV. For $T=3$ MeV, the closed shell ($Z=8$) light-mass fragment with its corresponding partners has larger scission point probabilities. But, at $T=2$ MeV, Si, P, and S are favorable fragments with the corresponding partners. It is noticed that the symmetric binary fragmentation along with the fixed third fragment for ${}^{242}\mathrm{Pu}$ and ${}^{236}\mathrm{U}$ is also favored at $T=1$ MeV.

The calcium isotopes have emerged as a critical testing ground for new microscopically derived shell-model interactions, and a great deal of experimental and theoretical focus has been directed toward this region. We investigate the relative spectroscopic strengths associated with $1f_{7/2}$ neutron hole states in ${}^{47,49}\mathrm{Ca}$ following one-neutron knockout reactions from ${}^{48,50}\mathrm{Ca}$. The observed reduction of strength populating the $7/2_1^{-}$ state in ${}^{49}\mathrm{Ca}$, as compared to ${}^{47}\mathrm{Ca}$, is inconsistent with shell-model calculations using both phenomenological interactions such as GXPF1, and interactions derived from microscopically based two- and three-nucleon forces. The result suggests a fragmentation of the $l=3$ strength to higher-lying states as suggested by the microscopic calculations, but the observed magnitude of the reduction is not reproduced in any shell-model description.

First, we present a concise glossary of formulas for composition of standard, cumulant, factorial, and factorial cumulant moments in superposition (compound) models, where final particles are created via independent emission from a collection of sources. Explicit mathematical formulas for the composed moments are given to all orders. We discuss the composition laws for various types of moments via the generating-function methods and list the formulas for the unfolding of the unwanted fluctuations. Second, the technique is applied to the difference of the scaled multiplicities of two particle types. This allows for a systematic derivation and a simple algebraic interpretation of the so-called strongly intensive fluctuation measures. With the help of the formalism we obtain several new strongly intensive measures involving higher-rank moments. The reviewed as well as the new results may be useful in investigations of mechanisms of particle production and event-by-event fluctuations in high-energy nuclear and hadronic collisions, and in particular in the search for signatures of the QCD phase transition at a finite baryon density.

We present a microscopic calculation of $\alpha$-cluster formation in heavy nuclei by using the quartetting wave function approach. The interaction of the quartet with the core nucleus is taken in local density approximation. The $\alpha$-cluster formation is found to be particularly sensitive to the interplay of the mean field felt by the $\alpha$-cluster and the Pauli blocking as a consequence of antisymmetrization. The striking feature of $\alpha$-cluster formation probability across the major shell closures of 82 protons and 126 neutrons is reproduced. The shell (or subshell) effects on the $\alpha$-cluster formation in superheavy nuclei are also analyzed.

For the first time, the complete neutron multiplicity distribution has been measured from the photofission of ${}^{235}\mathrm{U}$ induced by high-energy spallation $\gamma$ rays arriving ahead of the neutron beam at the Los Alamos Neutron Science Center. The resulting average neutron multiplicity $3.80\pm 0.08$ (stat.) neutrons per photofission is in general agreement with previous measurements. In addition, unique measurements of the prompt fission energy spectrum of the neutrons from photofission and the angular correlation of two-neutron energies emitted in photofission also were made. The results are compared to calculations with the complete event fission model freya.

Photoproduction of $K{\mathrm{\Sigma }}^{*}\left(1385\right)$ on the nucleon is investigated within the Regge framework, and the reaction mechanism is analyzed based on the data existing in the channels $\gamma p\to K^{+}{\mathrm{\Sigma }}^{*0}$ and $\gamma n\to K^{+}{\mathrm{\Sigma }}^{*-}$. The Reggeization of the $t$-channel meson exchanges $K\left(494\right)+K^{*}\left(892\right)+K_2^{*}\left(1430\right)$ is employed to construct the photoproduction amplitude. The Rarita-Schwinger formalism is applied for the spin-$3/2^{+}$ strangeness-baryon ${\mathrm{\Sigma }}^{*}$ with a special gauge prescription utilized for the convergence of these reaction processes. Within a set of coupling constants determined from the symmetry argument for $K$ and $K^{*}$ and from the duality and vector dominance for $K_2^{*}$, the data of both processes are reproduced to a good degree. The production mechanism of these processes is featured by the dominance of the contact term over the $K$ exchange. The role of $K_2^{*}$ is found to be more important than that of $K^{*}$.

We undertake a covariance error analysis of the pion-nucleon-nucleon coupling constants from the Granada-2013 $np$ and $pp$ database, comprising a total of 6720 scattering data below laboratory energy of 350 MeV. Assuming a unique pion-nucleon coupling constant in the one-pion exchange potential above a boundary radius $r_c=3\mathrm{fm}$ we obtain $f^2=0.0763\left(1\right)$. The effects of charge symmetry breaking on the ${}^{3}P_0$, ${}^{3}P_1$, and ${}^{3}P_2$ partial waves are analyzed and we find $f_p^2=0.0761\left(4\right)$, $f_0^2=0.0790\left(9\right)$, and $f_c^2=0.0772\left(6\right)$ with a strong anticorrelation between $f_c^2$ and $f_0^2$. We successfully test normality for the residuals of the fit. Potential tails in terms of different boundary radii as well as chiral two-pion-exchange contributions as sources of systematic uncertainty are also investigated.

The beyond-mean-field effects on nuclear triaxiality are studied by applying the projected total energy surface (PTES) calculations to the light tungsten isotopes ${}^{170\text{–}178}\text{W}$, which have been well described as prolate rotors within the mean-field approximation. The present PTES calculations have well reproduced the experimental energies of the yrast states and the available experimental transition quardrupole moment ($Q_t$) in function of spin. In particular, the results present a considerable large triaxiality for their ground states, with an average triaxial deformation $\gamma \sim {15}^{\circ }$. For a comparison, the total Routhian surface calculations have also been performed for these nuclei, the results show a well-established axial quadrupole deformation in their ground states. The presence of the significant triaxial deformation can be attributed to the beyond-mean-field effect as the angular momentum projection. This effect is therefore essential for a variety of mean-field approaches since it is only associated with the necessary restoration of the rotational symmetry in the laboratory frame, which is spontaneously broken in the intrinsic frame.

We investigate the effect of nontrivial spatial correlations between proton constituents, considered in this work to be gluonic hot spots, on the initial conditions of proton-proton collisions from ISR to Large Hadron Collider energies, i.e., $\sqrt{s}=52.6$, 7000, and 13 000 GeV. The inclusion of these correlations is motivated by their fundamental role in the description of a recently observed new feature of $pp$ scattering at $\sqrt{s}=7$ TeV, the hollowness effect. Our analysis relies on a Monte Carlo Glauber approach including fluctuations in the hot spot positions and their entropy deposition in the transverse plane. We explore both the energy dependence and the effect of spatial correlations on the number of wounded hot spots, their spatial distribution, and the eccentricities, ${\varepsilon }_n$, of the initial state geometry of the collision. In minimum bias collisions we find that the inclusion of short-range repulsive correlations between the hot spots reduces the value of the eccentricity (${\varepsilon }_2$) and the triangularity (${\varepsilon }_3$). In turn, upon considering only the events with the highest entropy deposition, i.e., the ultracentral ones, the probability of having larger ${\varepsilon }_{2,3}$ increases significantly in the correlated scenario. Finally, the eccentricities show a quite mild energy dependence.

Background: The interplay between collective and single-particle degrees of freedom is an important structure aspect to study. The nuclei in the $A\approx 180$ mass region are often denoted as good examples to study such problems because these nuclei are known to exhibit many rotational bands based on multi-quasiparticle $K$ isomers.

Purpose: A large set of high-quality experimental data on high-$K$ isomeric states in the $A\approx 180$ mass region has accumulated. A systematic description of them is a theoretical challenge as it requires a method going beyond the usual mean field with multi-quasiparticle configurations built in the shell-model basis. The $K$-isomer data provide an ideal testing ground for theoretical models.

Method: The recently extended projected shell model (PSM) by the Pfaffian method is employed with a sufficiently large configuration space including up to 10 quasiparticles. The restoration of rotational symmetry which is broken in the deformed mean field is obtained by means of angular-momentum projection. With axial symmetry in the basis deformation, each multi-quasiparticle state, classified by a $K$ quantum number, represents the major component of a rotational $K$ band. Shell-model diagonalization in such a projected basis defines the $K$ mixing, which is the key ingredient of the present method.

Results: Quasiparticle structure and rotational properties of high-$K$ isomers in even-even neutron-rich ${}^{174-186}\mathrm{W}$ isotopes are described. The rotational evolution of the yrast and near-yrast bands is discussed with successive band crossings. Multi-quasiparticle $K$ isomers and associated rotational bands in each W isotope are studied with detailed quasiparticle configurations given. Electromagnetic transition properties are also studied and the calculated $B\left(E2\right),B\left(M1\right)$, and $g$-factors are compared with experiment if data exist.

Conclusions: Many nuclei of the $A\approx 180$ mass region exhibit properties of an axially symmetric shape and $K$ is approximately a good quantum number. For such nuclei, the extended PSM assuming an axially symmetric basis but including $K$ mixing through diagonalization of the two-body Hamiltonian is an appropriate method to study multi-quasiparticle $K$ isomers and $K$ violations in these states. For special examples where one finds highly $K$-forbidden transitions the present model needs to be further improved.

We apply alternative representations of Holstein-Primakoff boson expansion to the particle-rotor model as useful probes to test the stability and the physical contents of the exact solution. The diagonal representations with the total and single-particle angular momenta along the same axis (longitudinal case) and along two perpendicular axes (transverse case) are employed according to the system with rigid or hydrodynamical moments of inertia (MoI). The longitudinal case gives the normal wobbling mode for rigid MoI, but does not give a stable solution for hydrodynamical MoI. The transverse case applied for hydrodynamical MoI describes a few low spin states with reduced alignment of the total spin in the parallel direction to the single-particle spin, but these states differ from the wobbling mode which involves a quantized unit of rotational angular momentum. Employing the angular-momentum-dependent rigid MoI which is derived from the self-consistent Hartree-Fock-Bogoliubov equation together with angular momentum and particle-number constraints, we obtain good fitting not only to the energy-level scheme, but also to the electromagnetic transition rates and the mixing ratio for ${}^{135}\mathrm{Pr}$.

We have developed a fully coupled-channels complex scaling method (ccCSM) for the study of the simplest (and thus most important) kaonic nucleus, $``K^{-}pp$”, which is a resonant state of a $\overline{K}NN\text{−}\pi \mathrm{\Sigma }N\text{−}\pi \mathrm{\Lambda }N$ coupled-channel system based on theoretical viewpoint. By employing the ccCSM and imposing the correct boundary condition for a resonance, the coupled-channel problem is solved using a phenomenological energy-independent potential. As a result of the ccCSM calculation of $``K^{-}pp$”, in which all three channels are treated explicitly, we have obtained a three-body resonance as a Gamow state. The resonance pole indicates that the binding energy of $``K^{-}pp$” and the half value of its mesonic decay width are 51 and 16 MeV, respectively. In the analysis of the ccCSM resonant wave function, we clarify the spatial configuration and channel composition of $``K^{-}pp$”. Compared with past single-channel calculations based on effective $\overline{K}N$ potentials, the current study provides a guideline for the determination of the $\overline{K}N$ energy to be used in such effective potentials.

The weak magnetism correction and its uncertainty to nuclear $\beta$ decay play a major role in determining the significance of the reactor neutrino anomaly. Here we examine the common approximation used for one-body weak magnetism in the calculation of fission antineutrino spectra, wherein matrix elements of the orbital angular-momentum operator contribution to the magnetic-dipole current are assumed to be proportional to those of the spin operator. Although we find this approximation invalid for a large set of nuclear structure situations, we conclude that it is valid for the relevant allowed $\beta$ decays between fission fragments. In particular, the uncertainty in the fission antineutrino due to the uncertainty in the one-body weak magnetism correction is found to be less than 1%. Thus, the dominant uncertainty from weak magnetism for reactor neutrino fluxes lies in the uncertainty in the two-body meson-exchange magnetic-dipole current.

We calculate $p_T$ spectra and elliptic flow for tip-tip and body-body configurations of full-overlap uranium-uranium $\left(\text{U}+\text{U}\right)$ collisions by using a hydrodynamic model with smooth initial density distribution and compare the results with those obtained from $\text{Au}+\text{Au}$ collisions at the BNL Relativistic Heavy Ion Collider (RHIC). Production of thermal photons is seen to be significantly larger for tip-tip collisions compared with body-body collisions of uranium nuclei in the region $p_T>1$ GeV. The difference in the results for the two configurations of $\text{U}+\text{U}$ collisions depends on the initial energy deposition which is yet to be constrained precisely from hadronic measurements. The thermal photon spectrum from body-body collisions is found to be close to the spectrum from most-central $\text{Au}+\text{Au}$ collisions at RHIC. The elliptic-flow parameter calculated for body-body collisions is found to be large and comparable to the $v_2\left(p_T\right)$ for mid-central collisions of Au nuclei. On the other hand, as expected, $v_2\left(p_T\right)$ is close to zero for tip-tip collisions. The qualitative nature of the photon spectra and elliptic flow for the two different orientations of uranium nuclei is found to be independent of the initial parameters of the model calculation. We show that the photon results from fully overlapping $\text{U}+\text{U}$ collisions are complementary to the results from $\text{Au}+\text{Au}$ collisions at RHIC.

Measurements of di-hadron azimuthal correlations at different centralities for Au+Au collisions at $200A$ GeV were reported by the PHENIX Collaboration. The data were presented for different ranges of transverse momentum. In particular, it was observed that the away-side correlation evolves from a double- to a single-peak structure when the centrality decreases. In this work, we show that these features naturally appear due to an interplay between the centrality-dependent smooth background elliptic flow and the one produced by event-by-event fluctuating peripheral tubes. To compare with the PHENIX data, we also carry out numerical simulations by using a hydrodynamical code nexspherio, and calculate the correlations by both cumulant and the ZYAM method employed by the PHENIX Collaboration. Our results are in reasonable agreement with the data. A brief discussion on the physical content of the present model and its difference from other viewpoints is also presented.

High-spin-level schemes of ${}^{118,119}\mathrm{Ag}$ are established for the first time by analyzing the high statistics $\gamma \text{−}\gamma \text{−}\gamma$ and $\gamma \text{−}\gamma \text{−}\gamma \text{−}\gamma$ coincidence data from the spontaneous fission of ${}^{252}\mathrm{Cf}$ at Gammasphere. Two bands with 12 new levels in ${}^{118}\mathrm{Ag}$ and three bands with 14 new levels in ${}^{119}\mathrm{Ag}$ have been identified. A total Routhian surface calculation and projected shell model calculation have been performed to understand the behavior of these two nuclei. The calculations indicate oblate shape in ${}^{118,119}\mathrm{Ag}$.

Excited states in the ${}^{101}\mathrm{Pd}$ nucleus were investigated through the ${}^{75}\mathrm{As}({}^{31}\mathrm{P},2p3n)$ fusion-evaporation reaction at $E_{\mathrm{lab}}=125$ MeV by using the Indian National Gamma Array spectrometer equipped with 21 clover Ge detectors. The level scheme is considerably extended for medium spin values. New positive-parity band structures in ${}^{101}\mathrm{Pd}$ have been studied within the framework of the projected shell model and are found to undergo transition from single quasiparticle to high-$K$ three quasiparticle configuration after band crossing, i.e., from principal-axis rotation to tilted-axis rotation. The negative-parity band structures are discussed in the framework of the hybrid version of tilted-axis cranking shell model calculations. The observed alignment gain in the lowest excited $\nu h_{11/2}$ negative-parity band results from successive ${\left(\nu g_{7/2}\right)}^2$ and ${\left(\pi g_{9/2}\right)}^2$ pair alignments. The higher excited negative-parity bands are reproduced for the $\nu \left[h_{11/2}{(g_{7/2}/d_{5/2})}^2\right]$ and ${\left(\pi g_{9/2}\right)}^{-2}\otimes \nu h_{11/2}$ configurations.