In the past, Dirac phenomenology has been used to determine global proton-nucleus optical potentials for a number of targets. ${}^4\mathrm{He}$ has not been previously included in these analyses. This paper addresses $p+$${}^4\mathrm{He}$ using medium-energy proton elastic scattering data with proton kinetic energies in the laboratory from 156 to 1728 MeV. The characteristic features of the optical potentials for $p+$${}^4\mathrm{He}$ are shown as well as the the predictive power of the global approach for this nucleus.

Quasi-elastic-scattering and transfer reaction cross-section measurements were made for the ${}^7\mathrm{Be}+{}^{27}\mathrm{Al}$ system at $E_{\mathrm{lab}}=17$, 19, and 21 MeV in the angular range ${\theta }_{c.m.}={12}^{°}-{43}^{°}$. An optical model (OM) analysis of the quasi-elastic scattering data was carried out. The fusion cross sections were derived at these energies by subtraction of the integrated transfer cross sections from the reaction cross sections obtained from the fits to quasi-elastic-scattering data. These fusion cross sections were found to be consistent with those obtained from the coupled-channels calculations. Elastic scattering and fusion cross sections were measured for the ${}^7\mathrm{Li}+{}^{27}\mathrm{Al}$ system at $E_{\mathrm{lab}}=10$, 13, 16, 19, and 24 MeV. For elastic scattering the angular coverages were in the ${\theta }_{\mathrm{lab}}={12}^{°}-{72}^{°}$ range and for fusion the α-evaporation spectra from the compound nucleus were measured in the angular range ${\theta }_{\mathrm{lab}}={52}^{°}-{132}^{°}$ (142° at 10 MeV). The elastic-scattering angular distributions were subjected to OM analysis. The α-evaporation spectra were reproduced with the statistical model calculations, and the fusion cross sections were extracted from them. The fusion cross sections were also extracted by subtraction of the integrated inelastic-scattering cross sections from the reaction cross sections obtained from the OM fits to the elastic-scattering data, and these fusion data were found to be consistent. The CCDEF calculations describe these data quite well. A comparison of the fusion data for the ${}^7\mathrm{Be}+{}^{27}\mathrm{Al}$ and ${}^7\mathrm{Li}+{}^{27}\mathrm{Al}$ systems shows a similar and consistent behavior.

Inelastic proton scattering to the $2_1^{+}$ state of neutron-rich ${}^{16}\mathrm{C}$ is studied in inverse kinematics using a 33-MeV/nucleon beam. The deformation parameter ${\beta }_{{\mathit{pp}}^{\text{'}}}=0.47(5)$ obtained is consistent with the global systematics of even-even nuclei, based on the homogeneous quantum liquid-drop model. This result contrasts that of a recent lifetime measurement for the $2_1^{+}$ state in ${}^{16}\mathrm{C}$, where an anomalously reduced $E2$ transition strength is observed. A combination of these two results yields a large $M_n/M_p$ ratio of about 7, indicating a dominant neutron contribution to the quadrupole collectivity.

We report values for the neutron electric to magnetic form factor ratio, $G_{\mathit{En}}/G_{\mathit{Mn}}$, deduced from measurements of the neutron's recoil polarization in the quasielastic ${}^2\mathrm{H}$$(\overrightarrow{e},e^{\text{'}}\overrightarrow{n})$${}^1\mathrm{H}$ reaction, at three $Q^2$ values of 0.45, 1.13, and 1.45 (GeV/c)${}^2$. The data at $Q^2=1.13$ and 1.45 (GeV/c)${}^2$ are the first direct experimental measurements of $G_{\mathit{En}}$ employing polarization degrees of freedom in the $Q^2>1$ (GeV/c)${}^2$ region and stand as the most precise determinations of $G_{\mathit{En}}$ for all values of $Q^2$.

Knowledge of the energy spectrum of ${}^8\mathrm{B}$ neutrinos is important for interpreting experiments that detect energetic neutrinos from the Sun. The neutrino spectrum deviates from the allowed $\beta$-decay approximation because of the broad $\alpha$-unstable ${}^8\mathrm{Be}$ final state and recoil order corrections. We have measured the total energy of the $\alpha$ particles emitted following the $\beta$ decay of ${}^8\mathrm{B}$. The measured $\alpha$ spectrum is inconsistent with a recent measurement of comparable precision. The $\alpha$ spectrum is fit using the R-matrix approach, which gives a functional form for the $\beta$-decay strength function for the transition from ${}^8\mathrm{B}$ to the accessible excitation energies in ${}^8\mathrm{Be}$. Both the positron and neutrino energy spectra, corrected for recoil order effects, are constructed from the strength function. The positron spectrum is in good agreement with a previous direct measurement. The neutrino spectrum disagrees with previous experiments.

The $\mathit{ep}\to e^{\text{'}}{\pi }^{+}n$ reaction was studied in the first and second nucleon resonance regions in the $0.25$ GeV${}^2<Q^2<0.65$ GeV${}^2$ range by use of the CLAS detector at Thomas Jefferson National Accelerator Facility. For the first time, to our knowledge, the absolute cross sections were measured, covering nearly the full angular range in the hadronic center-of-mass frame. We extracted the structure functions ${\sigma }_{\mathit{TL}},{\sigma }_{\mathit{TT}}$, and the linear combination ${\sigma }_T+\epsilon {\sigma }_L$ by fitting the $\varphi$ dependence of the measured cross sections and compared them with the MAID and Sato-Lee models.

The method of intermediate-energy Coulomb excitation has been widely used to determine absolute $B(E2;0_1^{+}\to 2_1^{+})$ quadrupole excitation strengths in exotic nuclei with even numbers of protons and neutrons. Transition rates measured with intermediate-energy Coulomb excitation are compared to their respective adopted values and for the example of ${}^{26}\mathrm{Mg}$ to the $B(E2;0_1^{+}\to 2_1^{+})$ values obtained with a variety of standard methods. Intermediate-energy Coulomb excitation is found to have an accuracy comparable to those of long-established experimental techniques.

The systematics of the $\pi h_{11/2}\otimes \nu h_{11/2}$ and $\pi h_{11/2}\otimes \nu s_{1/2}$ isomeric configurations was studied for the odd-Z $N=77$ isotones near the proton drip line. The isomeric decays in ${}^{140}\mathrm{Eu}$, ${}^{142}\mathrm{Tb}$, ${}^{144}\mathrm{Ho}$, and ${}^{146}\mathrm{Tm}$ were measured by means of x-ray, γ-ray, and charged particle spectroscopy at the Recoil Mass Spectrometer at the Holifield Radioactive Ion Beam Facility (ORNL). The spin and parity of $I^{\pi }=8^{+}$ and $5^{-}$ were deduced for the isomers in ${}^{140}\mathrm{Eu}$ and ${}^{142}\mathrm{Tb}$. New decay schemes were established, and the half-lives of the $8^{+}$ isomers were measured to be 302(4) ns for ${}^{140m2}\mathrm{Eu}$ and 25(1) μs for ${}^{142m2}\mathrm{Tb}$. No evidence for the expected $1^{+}$ ground-state was found in the ${}^{144}\mathrm{Ho}$ decay data. The proton-emission from ${}^{146}\mathrm{Tm}$ was restudied. Five proton transitions were assigned to two proton-emitting states. The half-lives of 198(3) ms and 68(3) ms and the spin and parity values of $I^{\pi }={10}^{+}$ and $5^{-}$ were established for ${}^{146m}\mathrm{Tm}$ and ${}^{146\mathrm{gs}}\mathrm{Tm}$, respectively. For the first time for an odd-odd nucleus, the interpretation of the observed decay properties and structure of the proton-emitting states was made by accounting for deformation and proton and neutron coupling to the core excitations. A complex wave-function structure was obtained, with dominating components of $\pi h_{11/2}\otimes \nu h_{11/2}$ for the ${10}^{+}$ isomer and $\pi h_{11/2}\otimes \nu s_{1/2}$ for the $5^{-}$ ground state.

The quantum chromodynamics phase diagram shows the phase transitions that can take place in matter at different temperatures and densities. In this work we discuss the possibility that γ-ray bursts might result from a phase change in the interior of a neutron star and calculate the energy released in the conversion of a metastable star into a stable star. We consider several different initial and several different final configurations. Initial metastable stars are taken as hadronic, hybrid, and quark stars with unpaired quarks; possible stable stars are hybrid and quark stars, taken both with unpaired and paired phases to study the deconfinement phase transition and normal quark matter–superconducting quark matter phase transition within a large number of relativistic models used to describe compact stars. The models used for the hadron matter are the nonlinear Walecka model and the quark-meson coupling model with and without hyperons. For the quark matter we have used the MIT bag model, the bag model with paired quarks to which we refer as the color-flavor-locked phase model, and the Nambu–Jona-Lasinio model. Within this mechanism we obtain energies of the order of ${10}^{50}-{10}^{53}$ erg, accounting for both long and short γ-ray bursts.

Calculations of two-particle correlations usually assume that particles interact only pairwise after their final collisions with third bodies. By considering classical trajectories, I show that interactions with the mean field can alter the spatial dimensions of the outgoing phase-space-density profiles, consistent with more complicated quantum complications. We find that if the pion dispersion relation is strongly modified, these distortions can be of the order of 10% or more.

A quantum chromodynamics phase transition may reflect in a inhomogeneous decoupling surface of hadrons produced in relativistic heavy-ion collisions. We show that because of the nonlinear dependence of the particle densities on the temperature and baryon-chemical potential such inhomogeneities should be visible even in the integrated, inclusive abundances. We analyze experimental data from Pb+Pb collisions at the Super Proton Synchrotron at Centre Européen de Recherches Nucléaires and Au+Au collisions at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory to determine the amplitude of inhomogeneities.

The liquid-gas phase transition in strange hadronic matter is reexamined by using the new parameters about the $\Lambda -\Lambda$ interaction deduced from recent observations of the ${}_{\Lambda \Lambda }^6\mathrm{He}$ double hypernucleus. The extended Furnstahl-Serot-Tang model with nucleons and hyperons is utilized. The binodal surface, the limit pressure, the entropy, the specific heat capacity and the caloric curves are addressed. We find that the liquid-gas phase transition can occur more easily in strange hadronic matter with weak Y-Y interaction than that of the strong Y-Y interaction.

A full fp calculation is performed for states which were degenerate in a single j-shell calculation in which isospin-zero two-body matrix elements were set to zero energy. Most of the splitting in a complete shell calculation (but not all) comes from the $T=0$ part of the interaction.

The well-known splitting of the isovector giant dipole resonance is traditionally explained as a phenomenon of the nuclear isospin asymmetry (isospin splitting model) or the nuclear deformation. We suggest a new mechanism of the splitting of the giant multipole resonances in spherical neutron-rich nuclei resulting from the interplay of the isovector and isoscalar sounds with different velocities. Our approach is based on the collisional Landau kinetic theory and can be used for description of the splitting phenomena for both the isoscalar and the isovector modes in a wide region of nuclear masses $A~40\text{−}240$. For the isovector dipole modes, the evaluated values of the splitting energy, the relative strength of the main and satellite resonance peaks, and the contribution to the energy-weighted sum rule are in agreement with experimental data.

The nucleus ${}^{49}\mathrm{Cr}$ has been studied by analyzing $\gamma \text{−}\gamma$ coincidences in the reaction ${}^{46}\mathrm{Ti}$($\alpha ,n$)${}^{49}\mathrm{Cr}$ at the bombarding energy of 12 MeV. The level scheme has been greatly extended at low excitation energy, and several lifetimes have been determined by means of the Doppler shift attenuation method. Shell model calculations in the full pf configuration space reproduce well the negative parity levels. Satisfactory agreement is obtained for positive parity levels by extending the configuration space to include a nucleon-hole in either the $1d_{3/2}$ or $2s_{1/2}$ orbitals. A nearly one-to-one correspondence is found between experimental and theoretical levels up to an excitation energy of 4 MeV. Experimental data and shell model calculations are interpreted in terms of the Nilsson diagram and the particle-rotor model, showing the strongly coupled nature of the bands in this prolate nucleus. Nine values of $K^{\pi }$ are proposed for the levels observed in this experiment. As a secondary result, it is shown that the values of the experimental magnetic moments in $1f_{7/2}$ nuclei are well reproduced without quenching the nucleon g factors.

The yrast level structure of ${}^{216}\mathrm{Rn}$ has been studied using in-beam spectroscopy α-γ-γ coincidence techniques through the ${}^{208}\mathrm{Pb}$(${}^{18}\mathrm{O}$, $2\alpha 2n$) reaction in the 91–93 MeV energy range, using the 8π GASP-ISIS spectrometer at Legnaro. The level scheme of ${}^{216}\mathrm{Rn}$ resulting from this study shows alternating parity bands only above a certain excitation energy. From this result, the lightest nucleus showing evidence of octupole collectivity at low spins is still ${}^{216}\mathrm{Fr}$, thereby defining the lowest-mass corner for this kind of phenomenon as $N\ge 129$ and $Z\ge 87$.

The final state distribution of the first six electronic states of ${}^3\mathrm{HeT}{}^{+},{}^3\mathrm{HeD}{}^{+}$ and ${}^3\mathrm{HeH}{}^{+}$ resulting from the β decay of $T_2$, DT, and HT are calculated, to satisfy the higher-resolution requirements and increased sensitivity of the future tritium neutrino mass experiments. The sensitivity of the initial temperature, ortho-para ratio, and isotopic composition of the source is considered. Estimates of the error in the value of the neutrino mass deduced from fitting, due to uncertainties in the temperature, the ortho-para ratio of $T_2$, and the percentage of DT molecules in the source are presented.

Analyzing powers in low-energy neutron scattering from ${}^{12}\mathrm{C}$ are calculated in an algebraic momentum-space coupled-channel formalism, that is, a multichannel algebraic scattering (MCAS) theory. The results are compared with recently obtained experimental data. The channel-coupling potentials have been defined previously to reproduce the total cross section and subthreshold bound states of the compound system. Without further adjustment, good agreement with data for the analyzing powers is obtained.

Dynamical instability modes of low-density asymmetric nuclear matter (ANM) neutralized by electrons as found in supernova core and neutron star crust are studied in the framework of relativistic mean-field hadron models with the inclusion of electron and photon fields. The dynamical and thermodynamical instability zones are compared. It is shown that the Coulomb field quenches large structure formation but has little effect on medium and small-size fluctuations that are, however, partially stabilized by the finite range of the nuclear forces. The electron dynamics tends to restore the large-wavelength instabilities but is moderated by the high-electron Fermi energy.

We propose to identify the new “intermediate” morphology in subsaturation nuclear matter observed in a recent quantum molecular dynamics simulation with the ordered bicontinuous double-diamond structure known in block copolymers. We estimate its energy density by incorporating the normalized area-volume relation given in a literature into the nuclear liquid drop model. The resulting energy density is higher than the other five known morphologies.