In this work, we study the quark energy spectrum in an MIT bag using the quark-meson coupling model. In particular, thermal distribution functions of quarks at finite temperature are explicitly incorporated into the calculations. It is found that when temperature is less than 50 MeV, the probability for a quark to occupy an exciting state is very rare and negligible, therefore the corresponding contributions to the thermodynamic potential under mean-field theory are strongly suppressed. In this context, if one calculates other physical quantities derived from thermodynamic potential, effects due to quark distribution functions are also likely to be unimportant.

The cross sections of the ${}^{130}$Sn($n,\gamma$)${}^{131}$Sn and ${}^{132}$Sn($n,\gamma$)${}^{133}$Sn reactions are calculated in the direct capture model at low energies below 1.5 MeV. Using recent data from ($d,p$) transfer experiments on ${}^{130}$Sn and ${}^{132}$Sn, it is possible to avoid global input parameters with their inherent uncertainties and to determine all inputs to the direct capture model by local adjustments. The calculated direct capture cross sections of ${}^{130}$Sn and ${}^{132}$Sn are almost identical and have uncertainties of less than a factor of 2. The stellar reaction rates $N_A〈\sigma v〉$ show a slight increase with temperature. Finally, an estimate for the influence of low-lying resonances to the stellar reaction rates is given.

Background: The density of the nucleus has been important in explaining the nuclear dependence of the quark distributions, also known as the EMC effect, as well as the presence of high-momentum nucleons arising from short-range correlations (SRCs). Recent measurements of both of these effects on light nuclei have shown a clear deviation from simple density-dependent models.

Purpose: A better understanding of the nuclear quark distributions and short-range correlations requires a careful examination of the experimental data on these effects to constrain models that attempt to describe these phenomena.

Methods: We present a detailed analysis of the nuclear dependence of the EMC effect and the contribution of SRCs in nuclei, comparing to predictions and simple scaling models based on different pictures of the underlying physics. We also make a direct, quantitative comparison of the two effects to further examine the connection between these two observables related to nuclear structure.

Results: We find that, with the inclusion of the new data on light nuclei, neither of these observables can be well explained by common assumptions for the nuclear dependence. The anomalous behavior of both effects in light nuclei is consistent with the idea that the EMC effect is driven by either the presence of high-density configurations in nuclei or the large virtuality of the high-momentum nucleons associated with these configurations.

Conclusions: The unexpected nuclear dependence in the measurements of the EMC effect and SRC contributions appear to suggest that the local environment of the struck nucleon is the most relevant quantity for explaining these results. The common behavior suggests a connection between the two seemingly disparate phenomena, but the data do not yet allow for a clear preference between models which aim to explain this connection.

The branching ratios of $K^{-}$ absorption in nuclear matter are theoretically investigated in order to understand the mechanism of $K^{-}$ absorption into nuclei. For this purpose mesonic and nonmesonic absorption potentials are evaluated as functions of nuclear density, the kaon momentum, and energy from one- and two-body $K^{-}$ self-energy, respectively. By using a chiral unitary approach for the $s$-wave $\overline{K}N$ amplitude we find that both the mesonic and nonmesonic absorption potentials are dominated by the $\Lambda \left(1405\right)$ contributions. The fraction of the mesonic and nonmesonic absorptions are evaluated to be respectively about $70\%$ and $30\%$ at the saturation density almost independently of the kaon momentum. We also observe different behavior of the branching ratios to ${\pi }^{+}{\Sigma }^{-}$ and ${\pi }^{-}{\Sigma }^{+}$ channels in mesonic absorption due to the interference between $\Lambda \left(1405\right)$ and the $I=1$ nonresonant background, which is consistent with experimental results. The nonmesonic absorption ratios $\left[\Lambda p\right]/\left[{\Sigma }^{0}p\right]$ and $\left[\Lambda n\right]/\left[{\Sigma }^{0}n\right]$ are about unity while $\left[{\Sigma }^{+}n\right]/\left[{\Sigma }^{0}p\right]$ and $\left[{\Sigma }^{-}p\right]/\left[{\Sigma }^{0}n\right]$ are about 2 due to the $\Lambda \left(1405\right)$ dominance in absorption. Taking into account the kaon momenta and energies, the absorption potentials become weaker due to the downward shift of the initial $K^{-}N$ two-body energy, but this does not drastirally change the nonmesonic fraction. The $\Sigma \left(1385\right)$ contribution in the $p$-wave $\overline{K}N$ amplitude is examined and found to be very small compared to the $\Lambda \left(1405\right)$ contribution in slow $K^{-}$ absorption.

The recently reported branching ratio (BR) for the 4${}^{+}$ state in ${}^{18}$Ne at E${}_{\mathrm{x}}$ = 7.06 MeV strongly disagrees with the BR computed using the known properties of this state.

We have reinvestigated the $\beta$ decay of ${}^{120}$Ag to levels in ${}^{120}$Cd. Significant deviations in the decays of low-lying states from that expected from a $\mathrm{U}\left(5\right)$ nucleus have been observed. The results from this paper which include the 0${}_2^{+}$ and 3${}_1^{+}$ states (which have now been correctly identified) and previous work on lighter Cd isotopes strongly suggest that the anharmonic vibrator description of the even-even Cd isotopes is inadequate. Analysis of the decay patterns and half-life information led to the determination that there are three $\beta$-decaying isomers in ${}^{120}$Ag, with $J^{\pi }$ assignments of (0${}^{-}$, 1${}^{-}$), 4(${}^{+}$), and 7(${}^{-}$). In addition, we have identified four candidates of the quadrupole-octupole quintuplet. These states are $J^{\pi }=\left(5^{-}\right)$ at 2489.5 keV, (4${}^{-}$) at 2208.4 keV, (2${}^{-}$) or (3${}^{-}$) at 2318.4 keV, and (1${}^{-}$) or (2${}^{-}$) at 2448.7 keV. All show strong transitions to the previously known 3${}^{-}$ octupole state at 1898.9 keV. The overall level scheme of ${}^{120}$Cd has been significantly expanded.

Excited states in ${}^{64}$Ni, ${}^{66}$Ni, and ${}^{68}$Ni were populated in quasielastic and deep-inelastic reactions of a 430-MeV ${}^{64}$Ni beam on a thick ${}^{238}$U target. Level schemes including many nonyrast states were established up to respective excitation energies of 6.8, 8.2, and 7.8 MeV on the basis of γ-ray coincidence events measured with the Gammasphere array. Spin-parity assignments were deduced from an angular-correlation analysis and from observed γ-decay patterns, but information from earlier γ-spectroscopy and nuclear-reaction studies was used as well. The spin assignments for nonyrast states were supported further by their observed population pattern in quasielastic reactions selected through a cross-coincidence technique. Previously established isomeric-state decays in ${}^{66}$Ni and ${}^{68}$Ni were verified and delineated more extensively through a delayed-coincidence analysis. A number of new states located above these long-lived states were identified. Shell-model calculations were carried out in the $p_{3/2}{f}_{5/2}{p}_{1/2}{g}_{9/2}$ model space with two effective interactions using a ${}^{56}$Ni core. Satisfactory agreement between experimental and computed level energies was achieved, even though the calculations indicate that all the states are associated with rather complex configurations. This complexity is illustrated through the discussion of the structure of the negative-parity states and of the M1 decays between them. The best agreement between data and calculations was achieved for ${}^{68}$Ni, the nucleus where the calculated states have the simplest structure. In this nucleus, the existence of two low-spin states reported recently was confirmed as well. Results of the present study do not indicate any involvement of collective degrees of freedom and confirm the validity of a shell-model description in terms of neutron excitations combined with a closed $Z$ $=$ 28 proton shell. Further improvements to the calculations are desirable.

Measurements have been performed at Los Alamos Neutron Science Center to acquire neutron fission spectra of ${}^{235}$U in the energy range between 0.5 and 10 MeV. These new data complement the currently available experimental data, which are not well known in the energy range below 1 and above 5 MeV. Organic liquid scintillation detectors (EJ-309s) were used together with a digital data-acquisition system. The EJ-309 detectors show excellent pulse shape discrimination capabilities and this is vital for identifying only neutron pulses and rejecting $\gamma$-ray pulses. The measurement data show the dependence of average fission neutron energy as a function of the inducing neutron energy. The data agree well with previously published measurements and Watt spectra fits for energies up to tens of MeV. At high fission-inducing neutron energies the spectrum deviates from Watt-spectra fits. The increased energy deposited in higher energy neutron-induced fissions does not significantly increase emitted fission neutron energies for up to 10 MeV. A significant decrease in neutron energy around second-chance fission cannot be observed beyond the current measurement uncertainties.

We present two-dimensional (2D) two-particle angular correlations measured with the STAR detector on relative pseudorapidity $\eta$ and azimuth $\varphi$ for charged particles from Au-Au collisions at $\sqrt{s_{\mathit{NN}}}=62$ and 200 GeV with transverse momentum $p_t\ge 0.15$ GeV/$c$, $\left|\eta \right|\le 1$, and $2\pi$ in azimuth. Observed correlations include a same-side (relative azimuth $<$$\pi /2$) 2D peak, a closely related away-side azimuth dipole, and an azimuth quadrupole conventionally associated with elliptic flow. The same-side 2D peak and away-side dipole are explained by semihard parton scattering and fragmentation (minijets) in proton-proton and peripheral nucleus-nucleus collisions. Those structures follow $N$-$N$ binary-collision scaling in Au-Au collisions until midcentrality, where a transition to a qualitatively different centrality trend occurs within one $10\%$ centrality bin. Above the transition point the number of same-side and away-side correlated pairs increases rapidly relative to binary-collision scaling, the $\eta$ width of the same-side 2D peak also increases rapidly ($\eta$ elongation), and the $\varphi$ width actually decreases significantly. Those centrality trends are in marked contrast with conventional expectations for jet quenching in a dense medium. The observed centrality trends are compared to perturbative QCD predictions computed in hijing, which serve as a theoretical baseline, and to the expected trends for semihard parton scattering and fragmentation in a thermalized opaque medium predicted by theoretical calculations and phenomenological models. We are unable to reconcile a semihard parton scattering and fragmentation origin for the observed correlation structure and centrality trends with heavy-ion collision scenarios that invoke rapid parton thermalization. If the collision system turns out to be effectively opaque to few-GeV partons the present observations would be inconsistent with the minijet picture discussed here.

We calculate the charge balance function of the bulk quark system before hadronization and those for the directly produced and the final hadron system in high energy heavy ion collisions. We use the variance coefficient to describe the strength of the correlation between the momentum of the quark and that of the antiquark if they are produced in a pair and fix the parameter by comparing the results for hadrons with the available data. We study the hadronization effects and decay contributions by comparing the results for hadrons with those for the bulk quark system. Our results show that while hadronization via quark combination mechanism slightly increases the width of the charge balance functions, it preserves the main features of these functions such as the longitudinal boost invariance and scaling properties in rapidity space. The influence from resonance decays on the width of the balance function is more significant but it does not destroy its boost invariance and scaling properties in rapidity space either. The balance functions in azimuthal direction are also presented.

The neutron-deficient nucleus ${}^{75}$Kr has been studied in two EUROBALL experiments. The analysis yielded a considerably extended level scheme including two newly observed excited high spin bands. The results are interpreted in the framework of the cranked Nilsson-Strutinsky approach. The calculations compare well to the experimentally established level scheme and predict the nucleus to be mainly prolate or triaxially deformed at high spin. Evidence for an oblate-prolate shape coexistence could not be found at high spin.

We study ${}^7$Li${(n,n^{\prime })}^7$Li${}^{*}$ reactions by using the continuum-discretized coupled-channels (CDCC) method with the complex Jeukenne-Lejeune-Mahaux effective nucleon-nucleon interaction. In this study, the ${}^7$Li nucleus is described by an $\alpha +t$ cluster model. The calculated elastic cross sections for incident energies between 11.5 and 24.0 MeV show good agreements with experimental data. Furthermore, we calculate the neutron spectra of ${}^7$Li ground and excited breakup states measured at selected angular points for incident energies of 11.5 and 18.0 MeV. The results reproduce the observed data systematically.

The photoproduction of the $J/\Psi$-${}^3\mathrm{He}$ bound state (${{[}^3\mathrm{He}]}_{J/\Psi }$) on a ${}^4\mathrm{He}$ target has been investigated using the impulse approximation. The calculations have been performed using several $\gamma +N\to J/\Psi +N$ models based on the Pomeron-exchange and accounting for the pion-exchange mechanism at low energies. The $J/\Psi$ wave functions in ${{[}^3\mathrm{He}]}_{J/\Psi }$ are generated from various $J/\Psi$-nucleus potentials which are constructed by either using a procedure based on the Pomeron-quark coupling mechanism or folding a $J/\Psi$-$N$ potential ($v_{J/\Psi ,N}$) into the nuclear densities. We consider $v_{J/\Psi ,N}$ derived from the effective field theory approach, lattice QCD, and Pomeron-quark coupling mechanism. The upper bound of the predicted total cross sections is about 0.1–0.3 pb. We also consider the possibility of photoproduction of a six quark-$J/\Psi$ bound state (${\left[q^6\right]}_{J/\Psi })$ on the ${}^3\mathrm{He}$ target. The compound bag model of $NN$ scattering and the quark cluster model of nuclei are used to estimate the $\left[q^6\right]$-$N$ wave function in ${}^3\mathrm{He}$ by imposing the condition that the calculated ${}^3\mathrm{He}$ charge form factor must be consistent with what is predicted by the conventional nuclear model. The upper bound of the predicted total cross sections of $\gamma +{}^3\mathrm{He}\to {\left[q^6\right]}_{J/\Psi }+N$ is about 2–4 pb, depending on the model of $\gamma +N\to J/\Psi +N$ used in the calculations. Our results call for the need of precise measurements of $\gamma +p\to J/\Psi +p$ and also the $\gamma +{}^2\mathrm{H}\to J/\Psi +n+p$ reactions near the threshold.

We have used the ${}^{10}$B(${}^3$He$,p\alpha$$\alpha$$\alpha$) reaction at 4.9 MeV and the ${}^{11}$B(${}^3$He$,d\alpha$$\alpha$$\alpha$) reaction at 8.5 MeV to determine the energy, width, and decay mechanism of resonances in ${}^{12}$C above the triple-$\alpha$ threshold up to 21 MeV in excitation energy. Comparison with various models has allowed us to estimate the degree of clustering of the states studied.

The restoration of parity symmetry has been performed in the framework of the highly truncated diagonalization approach, which is suited to treat correlations in an explicitly particle-number-conserving microscopic approach. To do so we have assumed axial symmetry and used a generalized Wick's theorem attributable to Löwdin in a projection-after-variation scheme. We have chosen the Skyrme SkM${}^{*}$ energy-density functional for the particle-hole channel and a density-independent $\delta$ force for the residual interaction. We have applied this approach in the region of the outer fission barrier of the ${}^{240}$Pu nucleus. As a result, we have shown that the $K^{\pi }=0^{+}$ fission isomeric state is statically unstable against intrinsic parity-breaking modes, while the projection does not affect the energy at the top of the intrinsic outer fission barrier. Altogether, this leads to an increase of the height of the outer fission barrier, with respect to the fission isomeric state, by about 350 keV, thus affecting significantly the spontaneous-fission half-life of the considered fission isomer.

Recent antisymmetrized molecular dynamics (AMD) calculations for ${}^{28}$Si suggest the presence of a superdeformed (SD) band with a dominant ${}^{24}\mathrm{Mg}+\alpha$ clustering for its configuration, with firm predictions for its location and associated moment of inertia. This motivates a review of the experimental results reported in the literature with a particular focus on ${}^{24}$Mg($\alpha$,$\gamma$) studies, as well as on $\alpha$-like heavy-ion transfer reactions such as ${}^{12}$C(${}^{20}$Ne,$\alpha$)${}^{28}$Si. Combining this information for the first time leads to a set of candidate SD states whose properties point to their $\alpha$-cluster structure and strong associated deformation. Analysis of data from Gammasphere allows the electromagnetic decay of these candidate states to be probed and reveals further supporting evidence for such a structure. This paper appraises this body of information and finds the evidence for an SD band is strong.

The shape isomers of the ${}^{28}$Si nucleus are derived from Nilsson model calculations combined with quasidynamical $\mathrm{SU}\left(3\right)$ symmetry considerations, and their possible binary clusterizations are determined. The results are compared with those of other calculations. Concerning the superdeformed state our finding gives support to the new candidate suggested by Jenkins et al. [Phys. Rev. C 86, 064308 (2012)].

We investigate the superfluid properties of the inner crust of neutron stars at finite temperature for different pairing functionals. We generalize the formalism adopted in Pastore et al. [Phys. Rev. C 84, 065807 (2011)] to include the effect of the temperature to calculate the specific heat of each given Wigner-Seitz cell. The calculations are done for two pairing forces, Gogny D1 and $V_{\mathrm{low}k}$, with finite range and a density-dependent contact interaction. We compare in such a way the effect of the pairing strength and of the range on the thermal properties of the inner crust.

The paper presents an analysis of pairings of mirror states above the proton threshold in ${}^{20}$Na with known states in ${}^{20}$F, including the astrophysically important resonance for the ${}^{19}$Ne($p$,$\gamma$)${}^{20}$Na reaction. This results in a fully comprehensive matching between the mirror levels in ${}^{20}$Na and ${}^{20}$F in this excitation energy region.