The features of net-baryon productions and collective flow in relativistic heavy-ion collisions at energies reached at the CERN Large Hadron Collider (LHC), BNL Relativistic Heavy Ion Collider (RHIC), CERN Super Proton Synchrotron (SPS), and BNL Alternating Gradient Synchrotron (AGS) with the model of nonuniform flow model (NUFM) are systematically studied in this paper. In particular we predict the feature of net-baryon productions and collective flow at LHC $\sqrt{s_{\mathit{NN}}}=5500$ GeV based on the detailed study at RHIC $\sqrt{s_{\mathit{NN}}}=62.4$ and 200 GeV. The dependencies of the features of baryon stopping and collective flow on the collision energies and centralities are investigated.

We report fragmentation cross sections measured at 0${}^{ˆ}$ for beams of ${}^{14}\mathrm{N}$, ${}^{16}\mathrm{O}$, ${}^{20}\mathrm{Ne}$, and ${}^{24}\mathrm{Mg}$ ions, at energies ranging from 290 MeV/nucleon to 1000 MeV/nucleon. Beams were incident on targets of C, CH${}_2$, Al, Cu, Sn, and Pb, with the C and CH${}_2$ target data used to obtain hydrogen-target cross sections. Using methods established in earlier work, cross sections obtained with both large-acceptance and small-acceptance detectors are extracted from the data and, when necessary, corrected for acceptance effects. The large-acceptance data yield cross sections for fragments with charges approximately half of the beam charge and above, with minimal corrections. Cross sections for lighter fragments are obtained from small-acceptance spectra, with more significant, model-dependent corrections that account for the fragment angular distributions. Results for both charge-changing and fragment production cross sections are compared to the predictions of the Los Alamos version of the quark gluon string model (LAQGSM) as well as the NASA Nuclear Fragmentation (NUCFRG2) model and the Particle and Heavy Ion Transport System (PHITS) model. For all beams and targets, cross sections for fragments as light as He are compared to the models. Estimates of multiplicity-weighted helium production cross sections are obtained from the data and compared to PHITS and LAQGSM predictions. Summary statistics show that the level of agreement between data and predictions is slightly better for PHITS than for either NUCFRG2 or LAQGSM.

This paper considers a spin-dependent neutron interaction with optical potentials (fields) from the strong interaction, the weak interaction, and an assumed $T$-violating interaction. The vector sum of these fields and their interferences determines an effective field of the target with an angular position in space due to polar and azimuthal angles. The phase of the azimuthal component is found to be the sum of two angles. The tangent of the first angle is equal to the ratio of the $T$-violating forward-scattering amplitude $D$ to the weak-interaction amplitude $C.$ The quantity is of interest. The tangent of the second angle depends on the spin rotation in the residual pseudomagnetic field of the target, and it can be treated as a background effect. This paper shows that the second angle has different signs in measurements with polarized and unpolarized neutrons; thus, two measurements allow it to be compensated for. In addition, the use of the Ramsey method of separated oscillatory fields for measurement of the neutron spin rotation angle, depending on the phase of the rf field in the Ramsey cell, allows a cosine-like spectrum to be measured. This spectrum is called a phase spectrum. The phase spectra measured with polarized and unpolarized targets have a phase shift. The measurements of this phase shift with polarized and nonpolarized neutrons at a $p$-wave resonance enable the ratio $D/C$ to be isolated. We also describe the algorithm for separating the ratio $D/C$, taking into account the influence of the fringing fields of the Ramsey coil magnet and the target magnet.

Gamma-ray telescopes in orbit around the earth are searching for evidence of the elusive radionuclide ${}^{22}\mathrm{Na}$ produced in novae. Previously published uncertainties in the dominant destructive reaction, ${}^{22}\mathrm{Na}$($p,\gamma$)${}^{23}\mathrm{Mg}$, indicated new measurements in the proton energy range of 150 to 300 keV were needed to constrain predictions. We have measured the resonance strengths, energies, and branches directly and absolutely by using protons from the University of Washington accelerator with a specially designed beam line, which included beam rastering and cold vacuum protection of the ${}^{22}\mathrm{Na}$ implanted targets. The targets, fabricated at TRIUMF-ISAC, displayed minimal degradation over a $~$20 C bombardment as a result of protective layers. We avoided the need to know the absolute stopping power, and hence the target composition, by extracting resonance strengths from excitation functions integrated over proton energy. Our measurements revealed that resonance strengths for $E_p=213$, 288, 454, and 610 keV are stronger by factors of 2.4–3.2 than previously reported. Upper limits have been placed on proposed resonances at 198, 209, and 232 keV. These substantially reduce the uncertainty in the reaction rate. We have re-evaluated the ${}^{22}\mathrm{Na}$($p,\gamma )$ reaction rate, and our measurements indicate the resonance at 213 keV makes the most significant contribution to ${}^{22}\mathrm{Na}$ destruction in novae. Hydrodynamic simulations including our rate indicate that the expected abundance of ${}^{22}\mathrm{Na}$ ejecta from a classical nova is reduced by factors between 1.5 and 2, depending on the mass of the white-dwarf star hosting the nova explosion.

Quasielastic scattering of ${}^6\mathrm{He}$ on a ${}^{12}\mathrm{C}$ target was measured at 82.3 MeV/nucleon. Special care was taken to treat the background subtraction at very small angles. The measured differential cross-sections show a large enhancement at small angles relative to the Rutherford cross-section, similar to those observed at lower energies for the scattering of halo nuclei. The overall structure of the cross-section is reasonably reproduced by the optical model calculations. The inelastic channels which populate two low-lying excited states of ${}^{12}\mathrm{C}$ target nucleus were included in the framework of the coupled channel analysis. Further systematic theoretical analysis is encouraged.

High-spin states in ${}^{161}\mathrm{Er}$ have been studied experimentally using the ${}^{150}\mathrm{Nd}$(${}^{16}\mathrm{O}$,5$\mathit{n}$) reaction at a beam energy of 86 MeV. The $5/2^{+}[642]$, $3/2^{-}[521]$, and $11/2^{-}[505]$ bands are extended up to high-spin states, and particularly the $\alpha =-1/2$ branch of the ground state $3/2^{-}[521]$ band is revised significantly. The relatively enhanced $E1$ transitions from the $3/2^{-}[521]$ band to the $5/2^{+}[642]$ band are observed. The band properties are analyzed within the framework of a triaxial particle-rotor model, and near-prolate shape and triaxial deformation are proposed to the $3/2^{-}[521]$ and $5/2^{+}[642]$ bands, respectively. Signature inversion occurs in the $3/2^{-}[521]$ band after the band crossing in ${}^{161}\mathrm{Er}$, and the systematics of the signature inversion associated with the $3/2^{-}[521]$ configuration are discussed. By analyzing the properties of the relatively enhanced $E1$ transitions, it is found that the $R(E1/E2)$ values show angular momentum dependence before the band crossing, and these enhanced $E1$ transitions could be attributed to octupole softness.

An improved description of single neutron stripping from ${}^{34,36,46}\mathrm{Ar}$ beams at 33 MeV/nucleon by a hydrogen target is presented and the dependence on the neutron-proton asymmetry of the spectroscopic factors is further investigated. A finite range adiabatic model is used in the analysis and compared to previous zero range and local energy approximations. Full three-body Faddeev calculations are performed to estimate the error in the reaction theory. In addition, errors from the optical potentials are also evaluated. From our new spectroscopic factors extracted from transfer, it is possible to corroborate the neutron-proton asymmetry dependence reported from knockout measurements.

All possible ternary fragmentations in fission of ${}^{252}\mathrm{Cf}$ are studied in collinear configuration within a spherical approximation using the recently proposed “three cluster model.” The potential energy surface of collinear configuration exhibits a strong valley around ${}^{48}\mathrm{Ca}$ and its neighboring nuclei ${}^{50}\mathrm{Ca}$, ${}^{54}\mathrm{Ti}$, and ${}^{60}\mathrm{Cr}$. Such strong minima are not seen in the potential energy surface of an equatorial configuration. As a consequence of strong minima in the potential, the overall relative yield is higher for the ternary fragmentation with ${}^{48}\mathrm{Ca}$, ${}^{50}\mathrm{Ca}$, ${}^{54}\mathrm{Ti}$, ${}^{60}\mathrm{Cr}$, and ${}^{82}\mathrm{Ge}$ as the third fragment. The results of potential energy and relative yield calculations reveal that collinear configuration increases the probability of emission of heavy fragments like ${}^{48}\mathrm{Ca}$ (doubly magic nucleus) and its neighboring nuclei as the third fragment. The obtained results indicate that the collinear configuration is the preferred configuration for intermediate nuclei (${}^{48}\mathrm{Ca}$, ${}^{50}\mathrm{Ca}$, ${}^{54}\mathrm{Ti}$, and ${}^{60}\mathrm{Cr}$) as the third fragment in particle accompanied fission while the equatorial configuration may be a preferred configuration for light nuclei (${}^4\mathrm{He}$, ${}^{10}\mathrm{Be}$) as the third fragment.

We introduce a new framework of highly anisotropic hydrodynamics that includes dissipation effects. Dissipation is defined by the form of the entropy source that depends on the pressure anisotropy and vanishes for the isotropic fluid. With a simple ansatz for the entropy source obeying general physical requirements, we are led to a nonlinear equation describing the time evolution of the anisotropy in purely longitudinal boost-invariant systems. Matter that is initially highly anisotropic approaches naturally the regime of the perfect fluid. Thus, the resulting evolution agrees with the expectations about the behavior of matter produced at the early stages of relativistic heavy-ion collisions. The equilibration is identified with the processes of entropy production.

The existence of the giant pairing vibration (GPV) in ${}^{120}\mathrm{Sn}$ and ${}^{208}\mathrm{Pb}$ was investigated using the ($p$,$t$) reaction at incident proton energies of 50 MeV and 60 MeV for the scattering angles 0${}^{°}$ and 7${}^{°}$. No clear signature for the GPV was found, providing an upper limit for the cross section of ${\sigma }_{\max }$ = 0.2 mb. Theoretical interpretations for the low cross section of the GPV are discussed.

The similarity renormalization group (SRG) is a continuous series of unitary transformations that can be implemented as a flow equation. When the relative kinetic energy ($T_{\mathrm{rel}}$) is used in the SRG generator, nuclear structure calculations have shown greatly improved convergence with basis size because of the decoupling of high-energy and low-energy physics. However this generator can sometimes be problematic. A test case is provided by a study of initial interactions from chiral effective field theories with large cutoffs, which can lead to spurious deeply bound states. We would like the SRG to decouple these from the physical shallow bound states. However, with $T_{\mathrm{rel}}$ the high- and low-energy bound states are not decoupled in the usual sense. Replacing $T_{\mathrm{rel}}$ by the momentum-space diagonal of the Hamiltonian ($H_d$) in the SRG generator does produce decoupling, such that the shallow states are in the low-momentum region and the deeply bound states are at higher momentum. The flow toward universal low-momentum interactions is also restored.

We study the sensitivity of transverse flow to symmetry energy in the Fermi energy region as well as at high energies. We find that transverse flow is sensitive to symmetry energy and its density dependence in the Fermi energy region. We also show that the transverse flow can address the symmetry energy at densities about twice the saturation density; however, it shows insensitivity to the symmetry energy at densities $\rho /{\rho }_0>2$. The mechanism for the sensitivity of transverse flow to symmetry energy and its density dependence is also discussed.

We study inclusive charged-current reaction through total cross sections of neutrino-nucleus scattering within the framework of a relativistic single-particle model in the quasielastic region. To describe the final-state interaction between knocked-out nucleons and the residual nucleus, a real potential of final nucleons, which is generated by a relativistic mean field, is used with the assumption of no loss of flux, which leads to current conservation and gauge invariance. We calculate $({\nu }_{\mu },{\mu }^{-})$ and $({\mathrm{\nu ̄}}_{\mu },{\mu }^{+})$ reactions. In these calculations, ${}^{12}\mathrm{C}$, ${}^{40}\mathrm{Ca}$, and ${}^{208}\mathrm{Pb}$ are used as target nuclei and the incident neutrino (antineutrino) energies are exploited up to 4 GeV. We find that the effect of the final-state interaction by the real potential of the knocked-out nucleons reduces cross sections by about 15%, similar to the effect of electron scattering. Furthermore, the effect of the Coulomb distortion for the outgoing leptons is shown to be different from the electron scattering. Finally, our total cross sections by scaling number of participated nucleons are presented to compare with experimental data.

The cross section of the reaction ${}^{197}\mathrm{Au}$($n,\gamma$) was measured with the time-of-flight technique at the n_TOF (neutron time-of-flight) facility in the unresolved resonance region between 5 and 400 keV using a pair of ${\mathrm{C}}_6$D${}_6$ (where D denotes ${}^2\mathrm{H}$) liquid scintillators for the detection of prompt capture $\gamma$ rays. The results with a total uncertainty of $3.9\%–6.7$$\%$ for a resolution of 20 bins per energy decade show fair agreement with the Evaluated Nuclear Data File Version B-VII.0 (ENDF/B-VII.0), which contains the standard evaluation. The Maxwellian-averaged cross section (MACS) at 30 keV is in excellent agreement with the one according to the ENDF/B-VII.0 evaluation and 4.7$\%$ higher than the MACS measured independently by activation technique. Structures in the cross section, which had also been reported earlier, have been interpreted as being due to clusters of resonances.

For understanding an anomalous nuclear effect experimentally observed for the beryllium-9 nucleus at the Thomas Jefferson National Accelerator Facility, clustering aspects are studied in structure functions of deep inelastic lepton-nucleus scattering by using momentum distributions calculated in antisymmetrized (or fermionic) molecular dynamics (AMD) and also in a simple shell model for comparison. According to AMD, the ${}^9\mathrm{Be}$ nucleus consists of two $\alpha$-like clusters with a surrounding neutron. The clustering produces high-momentum components in nuclear wave functions, which affects nuclear modifications of the structure functions. We investigated whether clustering features could appear in the structure function $F_2$ of ${}^9\mathrm{Be}$ along with studies for other light nuclei. We found that nuclear modifications of $F_2$ are similar in both AMD and shell models within our simple convolution description although there are slight differences in ${}^9\mathrm{Be}$. It indicates that the anomalous ${}^9\mathrm{Be}$ result should be explained by a different mechanism from the nuclear binding and Fermi motion. If nuclear-modification slopes $d(F_2^A/F_2^D)/\mathit{dx}$ are shown by the maximum local densities, the ${}^9\mathrm{Be}$ anomaly can be explained by the AMD picture, namely by the clustering structure, whereas it certainly cannot be described in the simple shell model. This fact suggests that the large nuclear modification in ${}^9\mathrm{Be}$ should be explained by large densities in the clusters. For example, internal nucleon structure could be modified in the high-density clusters. The clustering aspect of nuclear structure functions is an unexplored topic which is interesting for future investigations.

The $Q$ values of the neutrinoless double-electron capture transitions in ${}^{96}\text{Ru}$, ${}^{162}\text{Er}$, and ${}^{168}\text{Yb}$ have been determined by Penning-trap mass-ratio measurements. Based on our new high-precision results for the $Q$ values, neither of these transitions shows a resonant enhancement of the capture rate. At present, this excludes these nuclides from the list of suitable candidates in the search for neutrinoless double-electron capture.

Measurements consisting of $\gamma$-ray excitation functions and angular distributions were performed using the ($n,n^{\prime }\gamma$) reaction on ${}^{62}\mathrm{Ni}$. The excitation function data allowed us to check the consistency of the placement of transitions in the level scheme. From $\gamma$-ray angular distributions, the lifetimes of levels up to $~3.8$ MeV in excitation energy were extracted with the Doppler-shift attenuation method. The experimentally deduced values of reduced transition probabilities were compared with the predictions of the quadrupole vibrator model and with large-scale shell model calculations in the $\mathit{fp}$ shell configuration space. Two-phonon states were found to exist with some notable deviation from the predictions of the quadrupole vibrator model, but no evidence for the existence of three-phonon states could be established. $Z=28$ proton core excitations played a major role in understanding the observed structure.

We use simple analytic considerations and a Monte Carlo calculation of nucleons in a box to argue that the use of Jastrow functions as short-range correlators in the commonly employed two-body cluster approximation causes significant errors in the matrix elements for double-$\beta$ decay. The Jastrow approach appears to agree with others, however, if many-body clusters are included. A careful treatment of the charge-changing analog of the nuclear pair density shows, in addition, that differences between the unitary correlation operator method and Brueckner methods for treating short-range correlations in double-$\beta$ decay are less significant than suggested by previous work.