The Coulomb excitation experiment to study electromagnetic properties of the heaviest stable Mo isotope, ${}^{100}$Mo, was performed using a 76 MeV ${}^{32}$S beam from the Warsaw cyclotron U-200P. Magnitudes and relative signs of 26 $E1$, $E2$, $E3$, and $M1$ matrix elements coupling nine low-lying states in ${}^{100}$Mo were determined using the least-squares code gosia. Diagonal matrix elements (related to the spectroscopic quadrupole moments) of the 2${}_1^{+}$, 2${}_2^{+}$, and 2${}_3^{+}$ states as well as the 4${}_1^{+}$ state were extracted. The resulting set of reduced $E2$ matrix elements was complete and precise enough to obtain, using the quadrupole sum rules approach, quadrupole deformation parameters of ${}^{100}$Mo in its two lowest 0${}^{+}$ states: ground and excited. The overall deformation of the 0${}_1^{+}$ and 0${}_2^{+}$ states in ${}^{100}$Mo is of similar magnitude, in both cases larger compared to what was found for the neighboring isotopes ${}^{96}$Mo and ${}^{98}$Mo. At the same time, the asymetry parameters obtained for both states strongly differ, indicating a triaxial shape of the ${}^{100}$Mo nucleus in the ground state and a prolate shape in the excited 0${}^{+}$ state. Low-energy quadrupole excitations of the ${}^{100}$Mo nucleus were studied in the frame of the general quadrupole collective Bohr Hamiltonian model (GBH). The potential energy and inertial functions were calculated using the adiabatic time-dependent Hartree-Fock-Bogoliubov (ATDHFB) method starting from two possible variants of the Skyrme effective interaction: SIII and Sly4. The overall quadrupole deformation parameters resulting from the GBH calculations with the SLy4 variant of the Skyrme interaction are slightly closer to the experimentally obtained values than those obtained using SIII.

We report in a systematic way the predictions of the nonrelativistic hypercentral constituent quark model for the electromagnetic excitations of baryon resonances. The longitudinal and transverse helicity amplitudes are calculated with no free parameters for fourteen resonances, for both protons and neutrons. The calculations lead to an overall fair description of data, especially in the medium-$Q^2$ range, where quark degrees of freedom are expected to dominate.

We analyze the depolarization of ultracold neutrons confined in a magnetic field configuration similar to those used in existing or proposed magnetogravitational storage experiments aiming at a precise measurement of the neutron lifetime. We use an extension of the semiclassical Majorana approach as well as an approximate quantum mechanical analysis, both pioneered by Walstrom et al. [Nucl. Instrum. Methods Phys. Res. A 599, 82 (2009)]. In contrast with this previous work we do not restrict the analysis to purely vertical modes of neutron motion. The lateral motion is shown to cause the predominant depolarization loss in a magnetic storage trap. The system studied also allowed us to estimate the depolarization loss suffered by ultracold neutrons totally reflected on a nonmagnetic mirror immersed in a magnetic field. This problem is of preeminent importance in polarized neutron decay studies such as the measurement of the asymmetry parameter $A$ using ultracold neutrons, and it may limit the efficiency of ultracold neutron polarizers based on passage through a high magnetic field.

In two-proton pickup from ${}^{14}$C, the calculated cross-section ratio for the first two 0${}^{+}$ states of ${}^{12}$Be depends on the configuration mixing in these two states and on the amount of core excitation in the ground state (g.s.) of ${}^{14}$C. Using the ${}^{12}$Be wave functions that are reasonably well known, I have calculated this ratio as a function of the core excitation in ${}^{14}$C(g.s.). A measurement of this ratio should allow an independent determination of the ${}^{14}$C mixing—previously estimated to be about 12$\%$.

This paper gives new insight to the study of dynamical effects in proton breakup as compared to neutron breakup from a weakly bound state in an exotic nucleus. To clarify and assess quantitatively which mechanism would dominate the measured observables, we study here several reaction mechanisms separately but also their total effect, including interference. These mechanisms are (i) the recoil effect of the core-target Coulomb potential which we distinguish from the direct proton-target Coulomb potential, and (ii) nuclear breakup, which consists of stripping and diffraction. Direct Coulomb breakup typically gives cross sections about an order of magnitude larger than the recoil term, and the amount of nuclear diffraction vs Coulomb depends on the target. Thus for each mechanism the absolute values of breakup cross sections and parallel momentum distributions for ${}^8$B and ${}^{17}$F projectiles calculated on a light and a heavy target in a range of intermediate incident energies (40$A$–80$A$ MeV) are presented. Furthermore we study in detail the interference among the two Coulomb effects and nuclear diffraction. The calculation of the direct and recoil Coulomb effects separately and of their interference is the new and most relevant aspect of this paper.

We report on a comprehensive study of the phase structure of cold, dilute nuclear matter featuring a ${}^3{S}_1$-${}^3{D}_1$ condensate at nonzero isospin asymmetry, within wide ranges of temperatures and densities. We find a rich phase diagram comprising three superfluid phases, namely, a Larkin-Ovchinnikov-Fulde-Ferrell phase, the ordinary BCS phase, and a heterogeneous, phase-separated BCS phase, with associated crossovers from the latter two phases to a homogeneous or phase-separated Bose-Einstein condensate of deuterons. The phase diagram contains two tricritical points (one a Lifshitz point), which may degenerate into a single tetracritical point for some degree of isospin asymmetry.

We present measurements of the $J/\psi$ invariant yields in $\sqrt{s_{{}_{NN}}}=39$ and 62.4 GeV Au $+$ Au collisions at forward rapidity ($1.2<\left|y\right|<2.2$). Invariant yields are presented as a function of both collision centrality and transverse momentum. Nuclear modifications are obtained for central relative to peripheral Au $+$ Au collisions ($R_{\mathrm{CP}}$) and for various centrality selections in Au $+$ Au relative to scaled $p$ $+$ $p$ cross sections obtained from other measurements ($R_{\mathrm{AA}}$). The observed suppression patterns at 39 and 62.4 GeV are quite similar to those previously measured at 200 GeV. This similar suppression presents a challenge to theoretical models that contain various competing mechanisms with different energy dependencies, some of which cause suppression and others enhancement.

Cluster structures of excited ${}^{10}$Be states are investigated with a hybrid model of dineutron condensate wave functions and ${}^6\text{He}+\alpha$ cluster wave functions. Two kinds of cluster states are theoretically suggested a few MeV above the $\alpha +\alpha +n+n$ threshold energy. They have quite distinct cluster structure; ones have gaslike structures of $\alpha +\alpha +\text{dineutron}$, and the other has ${}^6\text{He}+\alpha$ with an extremely extended $\alpha$ cluster. Although these cluster states have not been confirmed experimentally yet, theoretically suggested properties of these states such as monopole transition strengths and $\alpha$-decay widths may be helpful for possible experimental observation.

In a recent work, Anderson et al. [Phys. Rev. C 82, 054001 (2010)] used the renormalization group (RG) evolution of the momentum distribution to show that, under appropriate conditions, operator expectation values exhibit factorization in the two-nucleon system. Factorization is useful because it provides a clean separation of long- and short-distance physics, and suggests a possible interpretation of the universal high-momentum dependence and scaling behavior found in nuclear momentum distributions. In the present work, we use simple decoupling and scale-separation arguments to extend the results of Anderson et al. to arbitrary low-energy $A$-body states. Using methods that are reminiscent of the operator product expansion (OPE) in quantum field theory, we find that the high-momentum tails of momentum distributions and static structure factors factorize into the product of a universal function of momentum that is fixed by two-body physics, and a state-dependent matrix element that is the same for both and is sensitive only to low-momentum structure of the many-body state. As a check, we apply our factorization relations to two well studied systems, the unitary Fermi gas and the electron gas, and reproduce known expressions for the high-momentum tails of each.

Previously a compact formula for total reaction cross section for heavy-ion collisions as a function of energy was obtained by treating the angular momentum $l$ as a continuous variable. The accuracy of the continuum approximation is assessed and corrections are evaluated. The accuracy of the compact equation can be improved by a simple modification, if a higher accuracy is required. Simple rules to determine the barrier heights and the penetration probability for the $l$ partial wave from experimental data are presented for the collision of identical or nonidentical light nuclei.

Excited states of ${}^{116}$Sb were investigated using in-beam $\gamma$-ray spectroscopy techniques with the ${}^{114}$Cd(${}^7$Li, $5n$) reaction. About 25 new states and 35 new transitions were added into the level scheme of ${}^{116}$Sb. The previously known two rotational bands based on the $\pi g_{9/2}^{}{}^{-1}\otimes \nu h_{11/2}$ and $\pi g_{9/2}^{}{}^{-1}\otimes \nu d_{5/2}$ configurations have been extended up to (16)${}^{-}$ and (13)${}^{+}$ states, respectively. A new $\Delta I=1$ band was identified, and interpreted in terms of the triaxial particle rotor model calculations.

Low-spin, high-excitation energy states in ${}^{88}$Y have been studied using the ${}^{89}$Y($p,d\gamma$) reaction. For this experiment a 25 MeV proton beam was incident upon a monoisotopic ${}^{89}$Y target. A silicon telescope array was used to detect deuterons, and coincident $\gamma$ rays were detected using a germanium clover array. Most of the known low-excitation-energy low-spin states populated strongly via the ($p,d$) reaction mechanism are confirmed. Two states are seen for the first time and seven new transitions, including one which bypasses the two low-lying isomeric states, are observed.

High spin levels of the very neutron-rich ${}^{152}$Ce have been investigated by measuring the prompt $\gamma$ rays in the spontaneous fission of ${}^{252}$Cf. The yrast band is confirmed and a new side-band has been identified. The side-band is tentatively assigned with negative parity and an octupole band structure with $s=+1$ in ${}^{152}$Ce has been proposed. Based on the theoretical calculations and systematic comparisons, the characteristics of the octupole correlations have been discussed.

We present calculations of the energy per particle of pure neutron and symmetric nuclear matter with simplified Argonne nucleon-nucleon potentials for different many-body theories. We compare critically the Brueckner-Hartree-Fock results to other formalisms, such as the Brueckner-Bethe-Goldstone expansion up to third order, self-consistent Green's functions, auxiliary field diffusion Monte Carlo, and Fermi hypernetted chain. We evaluate the importance of spin-orbit and tensor correlations in the equation of state and find these to be important in a wide range of densities.

Considering the nuclear reactions which involve specific features at certain regions of the $x$-Bjorken variable which was first observed by the EMC group, we indicate that the parton distributions in nuclei are not simply as the parton densities in nucleons. In addition to the most commonly analyzed data sets for deep-inelastic scattering of charged leptons off nuclei, we also analyze the Drell-Yan dilepton production. We investigate parametrizations of nuclear parton distributions at the next-to-leading order (NLO) of ${\alpha }_s$. Finally, optimum nuclear structure functions are determined by a ${\chi }^2$ analysis of experimental data for the nuclear structure function $F_2^A$/$F_2^{A^{\prime }}$ and Drell-Yan cross-section ratios. The related uncertainties are estimated by the Hessian method. Our results are in good agreement with the available experimental data and better than the results of some other fitting parametrization methods.

Until now, the mass asymmetry in the nuclear fission process has been understood in terms of the strong influence of the nuclear structure of the nascent fragments. Recently, a surprising asymmetric fission has been discovered in the light mercury region and has been interpreted as the result of the influence of the nuclear structure of the parent nucleus, totally discarding the influence of the fragments' structure. To assess the role of the fragment shell effects in the mass asymmetry in this particular region, a scission-point model, based on a full energy balance between the two nascent fragments, has been developed using one of the best theoretical descriptions of microscopic nuclear structure. As for actinides, this approach shows that the asymmetric splitting of the ${}^{180}$Hg nucleus and the symmetric one of ${}^{198}$Hg can be understood on the basis of only the microscopic nuclear structure of the fragments at scission.

The influence of the structure of projectile and target nuclei on the capture cross sections was investigated for the reactions ${}^{34}\mathrm{S}+{}^{204,206,208}$Pb and ${}^{36}\mathrm{S}+{}^{204,206,208}$Pb. Capture cross sections were deduced by measuring the fission fragments using multiwire proportional counters. An enhancement of the capture cross sections relative to a one-dimensional barrier penetration model was observed for all reactions at energies below the interaction barriers. The enhancement is larger in the case of reactions with ${}^{34}$S than with ${}^{36}$S. This observation is explained by a stronger coupling to the vibrational states in the reactions with ${}^{34}$S. Comparing the capture cross sections and the evaporation-residue cross sections for the reactions ${}^{36}\mathrm{S}+{}^{206}$Pb and ${}^{34}\mathrm{S}+{}^{208}$Pb, both yielding the same compound nucleus ${}^{242}$Cf, it is shown that the latter reaction has a lower fusion probability.

The use of quasielastic electron nucleus scattering is shown to provide significant constraints on models of the proton electromagnetic form factor of off-shell nucleons. Such models can be constructed to be consistent with constraints from current conservation and low-energy theorems, while also providing a contribution to the Lamb shift that might potentially resolve the proton radius puzzle in muonic hydrogen. However, observations of quasielastic scattering limit the overall strength of the off-shell form factors to values that correspond to small contributions to the Lamb shift.

Based on a microscopic description of superfluidity in overflowing nuclear systems, it is shown that continuum coupling plays an important role in the suppression, the persistence, and the reentrance of pairing. In such systems, the structure of the drip-line nucleus determines the suppression and the persistence of superfluidity. The reentrance of pairing with increasing temperature leads to additional critical temperatures between the normal and superfluid phases.