We determined the structure function ratio $R_{\mathrm{EMC}}^d=F_2^d/(F_2^n+F_2^p)$ from recently published $F_2^n/F_2^d$ data taken by the BONuS experiment using CLAS at Jefferson Lab. This ratio deviates from unity, with a slope $d{R}_{\mathrm{EMC}}^d/dx=-0.10\pm 0.05$ in the range of Bjorken $x$ from 0.35 to 0.7, for invariant mass $W>1.4$ GeV and $Q^2>1{\mathrm{GeV}}^2$. The observed EMC effect for these kinematics is consistent with conventional nuclear physics models that include off-shell corrections, as well as with empirical analyses that find the EMC effect proportional to the probability of short-range nucleon-nucleon correlations.

We study the diversities in the properties of the neutron stars arising due to the different choices for the cross coupling between various mesons, which governs the density dependence of the nuclear symmetry energy in the extended relativistic mean-field (RMF) model. For this purpose, we obtain two different families of the extended RMF model corresponding to different nonlinear cross-coupling terms in the isovector part of the effective Lagrangian density. The lowest-order contributions for the $\delta$ mesons are also included. The different models within the same family yield wide variation in the value of neutron-skin thickness in the ${}^{208}\mathrm{Pb}$ nucleus. These models are employed to compute the neutron-star properties such as core-crust transition density, radius and red shift at canonical mass $(1.4M_{\odot })$, tidal polarizability parameter, and threshold mass required for the enhanced cooling through the direct Urca process. Most of the neutron-star properties considered are significantly different(10–40%) for the different families of models at a smaller neutron-skin thickness $(\sim 0.15\mathrm{fm})$ in the ${}^{208}\mathrm{Pb}$ nucleus.

Measurement of nuclear cross sections at astrophysical energies involving unstable species is one of the most challenging tasks in experimental nuclear physics. The use of indirect methods is often unavoidable in this scenario. In this paper the Trojan horse method is applied for the first time to a radioactive ion beam-induced reaction studying the ${}^{18}\mathrm{F}(p,\alpha$)${}^{15}\mathrm{O}$ process at low energies relevant to astrophysics via the three-body reaction ${}^2\mathrm{H}{(}^{18}\mathrm{F},{\alpha }^{15}\mathrm{O})n$. The knowledge of the ${}^{18}\mathrm{F}{(p,\alpha )}^{15}\mathrm{O}$ reaction rate is crucial to understand the nova explosion phenomena. The cross section of this reaction is characterized by the presence of several resonances in ${}^{19}\mathrm{Ne}$ and possibly interference effects among them. The results reported in literature are not satisfactory and new investigations of the ${}^{18}\mathrm{F}{(p,\alpha )}^{15}\mathrm{O}$ reaction cross section will be useful. In the present work the spin-parity assignments of relevant levels have been discussed and the astrophysical $S$ factor has been extracted considering also interference effects.

An $R$-matrix model for three-body final states is presented and applied to a recent measurement of the neutron energy spectrum from the ${}^3\mathrm{H}+{}^3\mathrm{H}\to 2n+\alpha$ reaction. The calculation includes the $n\alpha$ and $nn$ interactions in the final state, angular momentum conservation, antisymmetrization, and the interference between different channels. A good fit to the measured spectrum is obtained, where clear evidence for the ${}^5\mathrm{He}$ ground state is observed. The model is also used to predict the $\alpha$-particle spectrum from ${}^3\mathrm{H}+{}^3\mathrm{H}$ as well as particle spectra from ${}^3\mathrm{He}+{}^3\mathrm{He}$. The $R$-matrix approach presented here is very general and can be adapted to a wide variety of problems with three-body final states.

Background: For nuclei heavier than ${}^{208}\mathrm{Pb}\alpha$ decay is a dominating decay mode. $\alpha$ decay of odd nuclei can give spectroscopic information because different states in the daughter nucleus can be populated in the decay.

Purpose: To explore and test microscopic descriptions of $\alpha$ decay of odd nuclei based on self-consistent models with effective nuclear interactions. To predict the hindrance of $\alpha$ decay of odd-$A$ superheavy nuclei.

Methods: We apply the method of our previous work [D. E. Ward, B. G. Carlsson, and S. Åberg, Phys. Rev. C 88, 064316 (2013)] to the case of odd-$A$ near-spherical nuclei. The Skyrme effective interaction SLy4 is used. Starting from the obtained Hartree-Fock-Bogoliubov vacuum and quasiparticle excitations, the $\alpha$-particle formation amplitude is calculated giving the decay rates and hindrance of different $\alpha$-decay channels.

Result: The calculated relative decay rates show good agreement with available data. The hindrance of decay channels where the odd nucleon changes orbital is reasonably described by the microscopic calculation. Several hindered ground-state decays of superheavy nuclei are predicted, implying possible $\alpha \text{−}\gamma$ coincidences.

Conclusions: The approach offers a practical method of making quantitative predictions for the relative hindrance of different $\alpha$-decay channels.

In this paper we report on a new study of prompt $\gamma$-rays from the spontaneous fission of ${}^{252}\mathrm{Cf}$. Photons were measured in coincidence with fission fragments by employing four different lanthanide halide scintillation detectors. Together with results from a previous work of ours, we determined characteristic parameters with high precision, such as the average $\gamma$-ray multiplicity ${\overline{\nu }}_{\gamma }=(8.29\pm 0.13)$, the average energy per photon ${\epsilon }_{\gamma }=(0.80\pm 0.02)$ MeV, and the total $\gamma$-ray energy release per fission $E_{\gamma ,\text{tot}}=(6.65\pm 0.10)$ MeV. The excellent agreement between the individual results obtained in all six measurements proves the good repeatability of the applied experimental technique. The impact of low-energy photons, i.e., below 500 keV, on prompt fission $\gamma$-ray spectra characteristics has been investigated as well by comparing our results with those taken with the DANCE detector system, which appears to suffer from absorption effects in the low-energy region. Correction factors for this effect were estimated, giving results comparable to ours as well as to historical ones. From this we demonstrate that the different techniques of determining the average $\gamma$-ray multiplicity, either from a properly measured and normalized spectrum or a measured multiplicity distribution, give equivalent and consistent results.

We investigate the structure of the light nuclei based on the modified chiral quark model $\left(\chi \mathrm{QM}\right)$, for the first time. To this end, we first calculate the parton distribution functions (PDFs) of the bounded nucleons using the $\chi \mathrm{QM}$ and then compute those of the light nuclei. For this purpose, it is first needed to obtain the bare quark densities inside the bounded nucleons of the nucleus. These bare distributions are calculated by applying the quark exchange model (QEM) in this article. Finally, we obtain the quark, antiquark, and gluon distributions and also the structure functions (SFs) of the bound state nucleons and the light nuclei at low $Q^2$ scale $(Q^2=0.35{\mathrm{GeV}}^2)$. These distributions can be evolved to the higher scales using DGLAP evolution equations. It is shown that the results of our theoretical framework are in good agreement with the experimental data and they also have appropriate behavior in comparison with the different parametrization models.

In this work, we study the arising of correlations among some isoscalar $(K_o$, $Q_o$, and $I_o)$ and isovector $(J$, $L_o$, $K_{\text{sym}}^o$, $Q_{\text{sym}}^o$, and $I_{\text{sym}}^o)$ bulk parameters in nonrelativistic and relativistic hadronic mean-field models. For the former, we investigate correlations in Skyrme and Gogny parametrizations, as well as in the nonrelativistic (NR) limit of relativistic point-coupling models. We provide analytical correlations among bulk parameters for the NR limit, discussing the conditions in which they are linear ones. Based on a recent study [Santos et al., Phys. Rev. C 90, 035203 (2014)], we also show that some correlations presented in the NR limit are reproduced for relativistic models presenting cubic and quartic self-interactions in the scalar field $\sigma$, mostly studied in this work in the context of the relativistic framework. We also discuss how the crossing points, observed in the density dependence of some bulk parameters, can be seen as a signature of linear correlations between the specific bulk quantity presenting the crossing and its immediately next order parameter.

Proton pairing vibrational states in ${}^{208}\mathrm{Pb}$ isotones with $76\le Z\le 88$ protons are described like neutron pairing vibrational states in lead isotopes with $120\le N\le 132$ neutrons within the model of pair addition and pair removal phonons. The anharmonicity calculated with three parameters reproduces the known energies within less than 5%. The interaction between the pairing phonons for protons and neutrons is similar in a striking manner.

Collective quadrupole and octupole states are described in a series of Sm and Gd isotopes within the framework of the interacting boson model (IBM), whose Hamiltonian parameters are deduced from mean-field calculations with the Gogny energy density functional. The link between both frameworks is the (${\beta }_2{\beta }_3$) potential energy surface computed within the Hartree-Fock-Bogoliubov framework in the case of the Gogny force. The diagonalization of the IBM Hamiltonian provides excitation energies and transition strengths of an assorted set of states including both positive- and negative-parity states. The resultant spectroscopic properties are compared with the available experimental data and also with the results of the configuration mixing calculations with the Gogny force within the generator coordinate method (GCM). The structure of excited $0^{+}$ states and its connection with double-octupole phonons is also addressed. The model is shown to describe the empirical trend of the low-energy quadrupole and octupole collective structure fairly well and turns out to be consistent with GCM results obtained with the Gogny force.

The production of hassium isotopes ${}^{266–271}\mathrm{Hs}$ in various reactions ${}^{22}\mathrm{Ne}+{}^{249}\mathrm{Cf},{}^{25,26}\mathrm{Mg}+{}^{248}\mathrm{Cm},{}^{30}\mathrm{Si}+{}^{244}\mathrm{Pu},{}^{34,36}\mathrm{S}+{}^{238}\mathrm{U},{}^{40}\mathrm{Ar}+{}^{232}\mathrm{Th}$, and ${}^{48}\mathrm{Ca}+{}^{226}\mathrm{Ra}$ is studied within the dinuclear system model. The experimental excitation functions of the isotopes ${}^{266–271}\text{Hs}$ are well described and predictions are made for future experiments.

In view of new constraints put forth by recent observations and measurements in the realm of astrophysics and nuclear physics, we update the nonlinear realization of the $\sigma$ model as to reflect such constraints. By doing this, we obtain new equations of state that may be used to describe neutron stars. Such equations of state are obtained by investigating different ways by which the vector mesons self-interact. Furthermore, we also investigate the role played by $\delta$ mesons in the model. As a result, we are able to develop equations of state that are in better agreement with data, such as nuclear compressibility and slope of the symmetry energy at saturation, star masses, radii, and cooling profiles.

Excited states in the odd-odd, highly neutron-deficient nucleus ${}^{166}\mathrm{Re}$ have been investigated via the ${}^{92}\mathrm{Mo}({}^{78}\mathrm{Kr},3p1n){}^{166}\mathrm{Re}$ reaction. Prompt $\gamma$ rays were detected by the JUROGAM II $\gamma$-ray spectrometer, and the recoiling fusion-evaporation products were separated by the recoil ion transport unit (RITU) gas-filled recoil separator and implanted into the Gamma Recoil Electron Alpha Tagging spectrometer located at the RITU focal plane. The tagging and coincidence techniques were applied to identify the $\gamma$-ray transitions in ${}^{166}\mathrm{Re}$, revealing two collective, strongly coupled rotational structures, for the first time. The more strongly populated band structure is assigned to the $\pi h_{11/2}\left[514\right]9/2^{-}\otimes \nu i_{13/2}\left[660\right]1/2^{+}$ Nilsson configuration, while the weaker structure is assigned to be built on a two-quasiparticle state of mixed $\pi h_{11/2}\left[514\right]9/2^{-}\otimes \nu \left[h_{9/2}{f}_{7/2}\right]3/2^{-}$ character. The configuration assignments are based on the electromagnetic characteristics and rotational properties, in comparison with predictions from total Routhian surface and particle-rotor model calculations.

A universal curve is one of the simple ways to get preliminary information about the $\alpha$-decay half-life times of heavy nuclei. We try to find parametrization for the universal curve of $\alpha$ decay based on semi-microscopic calculations starting from the realistic Michigan-three-Yukawa Reid nucleon-nucleon interaction. Within the deformed density-dependent cluster model, the penetration probability and the assault frequency are calculated using the Wentzel-Kramers-Brillouin approximation. The deformations of daughter nuclei and the ground-state spin and parity of the involved nuclei are considered. For all studied decays, we found that it is accurate enough to express the assault frequency either as a function of the mass number of the parent nuclei or as a constant average value. The average preformation probability of the $\alpha$ cluster inside four groups of 166 even- $\left(Z\right)$ -even $\left(N\right)$, 117 odd-even, 141 even-odd, and 72 odd-odd $\alpha$ emitters is obtained, individually. The effects of participating unpaired nucleons in the involved nuclei as well as the influence of any differences in their ground-state spin and/or parity appear in the obtained average values of the preformation probability. We suggested a single universal curve for $\alpha$ decay with only one parameter. This parameter varies according to the classified four groups. It includes the preformation probability and the average assault frequency in addition to the pairing contribution.

We present new experimental results for the ${}^3\mathrm{He}$ spin structure function $g_2$ in the resonance region at $Q^2$ values between 1.2 and 3.$0(\text{GeV}/c){}^2$. Spin dependent moments of the neutron were extracted. Our main result, the inelastic contribution to the neutron $d_2$ matrix element, was found to be small at $\langle Q^2\rangle =2.4{(\mathrm{GeV}/c)}^2$ and in agreement with the lattice QCD calculation. The Burkhardt-Cottingham sum rule for ${}^3\mathrm{He}$ and the neutron was tested with the measured data and using the Wandzura-Wilczek relation for the low $x$ unmeasured region.

The search for neutrinoless double-beta decay $\left(0\nu \beta \beta \right)$ requires extremely low background and a good understanding of their sources and their influence on the rate in the region of parameter space relevant to the $0\nu \beta \beta$ signal. We report on studies of various $\beta$ and $\gamma$ backgrounds in the liquid-xenon-based EXO-$2000\nu \beta \beta$ experiment. With this work we try to better understand the location and strength of specific background sources and compare the conclusions to radioassay results taken before and during detector construction. Finally, we discuss the implications of these studies for EXO-200 as well as for the next-generation, tonne-scale nEXO detector.

Based on Bohr model, I have presented a general formalism describing the collective motion for any deformed system, in which the collective Hamiltonian is expressed as vibrations in the body-fixed frame, rotation of whole system around the laboratory frame, and coupling between vibrations and rotation. Under the condition of decoupling approximation, I have derived the quantized Hamiltonian operator. Based on the operator, I have calculated the rotational spectra for some special octupole and hexadecapole deformed systems and shown their dependencies on deformation. The result indicates that the contribution of octupole or hexadecapole deformations to the lowest band is regular, while that to higher bands is dramatic. These features reflecting octupole and hexadecapole deformations are helpful in recognizing the properties of real nuclei with octupole and/or hexadecapole deformations coexisting with quadrupole deformations.

The curvature correction term to the surface tension is used as a criterion for the efficiency of the Skyrme interaction in describing surface properties. Based on the nuclear equation of state, the curvature correction term to the surface tension coefficient is calculated for 97 standard Skyrme interaction parameter sets in the vicinity of nuclear saturation density at zero temperature. The main idea is to find those parametrizations that give the Tolman $\delta$ correction close to the available theoretical predictions from the statistical theory. Only 59 out of 97 models give satisfactory results. Comparison of the obtained results with the results of the implementation of different macroscopic and microscopic constraints to Skyrme parametrizations available in the literature allows us to select four models that satisfy all the constraints.

The magnetic form factors of the odd-$As\text{−}d$ shell nuclei ${}^{17}\mathrm{O},{}^{25}\mathrm{Mg},{}^{27}\mathrm{Al},{}^{29}\mathrm{Si}$, and ${}^{31}\mathrm{P}$ are studied within the relativistic frame with single-nucleon wave functions generated using the relativistic mean field model. Single valence-nucleon contributions to the nuclear magnetic form factors are calculated, and two sets of quenching ratios of the nuclear magnetic form factors relative to the single valence-nucleon contributions are extracted for each nucleus. It is found that the single valence-nucleon contributions can generally give a good approximate description for the shapes of the nuclear magnetic form factors, including the positions of the minima and maxima, and after the quenching ratios are applied the experimental data can be very well reproduced. The quenching ratios are compared with those obtained within some other nuclear models, and the physical implications for each nucleus are discussed. Calculations also show that no reasonable quenching ratios could be found for ${}^{27}\mathrm{Al}$ when ${\mu }_{\mathrm{expt}.}/{\mu }_{s.n.}$ is chosen as the $M1$ multipole quenching ratio. This implies that the common way of choosing ${\mu }_{\mathrm{expt}.}/{\mu }_{s.n.}$ as the $M1$ multipole quenching ratio for the odd-$A$ nuclei is not always valid.