Pionless effective field theory with dibaryon fields is reexamined for observables involving the deuteron. The electromagnetic form factors of the deuteron and the total cross section of radiative neutron capture on the proton, $np\to d\gamma$, are calculated. The low-energy constants of vector-(photon-)dibaryon-dibaryon vertices in the effective Lagrangian are fixed primarily by the one-body vector-(photon-)nucleon-nucleon interactions. This scheme for fixing the values of the low-energy constants satisfactorily reproduces the results of the effective range theory. We also show that, by including higher-order corrections, we can obtain results that are close to those of the Argonne v18 potential model.

Level structures of ${}^{113,115,117}\mathrm{Pd}$ have been studied using the Gammasphere and a spontaneous fission source of ${}^{252}\mathrm{Cf}$. A new 85.1-keV transition was identified in ${}^{113}\mathrm{Pd}$. This indicates that the spin and parity of the isomeric state is 9/2${}^{-}$ rather than the previously assigned ${11/2}^{-}$. New low-energy transitions are confirmed in ${}^{115,117}\mathrm{Pd}$. In ${}^{115}\mathrm{Pd}$, the 39.0.- and 49.0-keV transitions are shown to be in prompt coincidence. This coincidence relationship indicates a spin and parity assignment of ${1/2}^{+}$ for the ground state rather than the previously assigned ${3/2}^{+}$.

Coupled-channel calculations are performed for the ${}^{12}\mathrm{C}$($d,p$)${}^{13}\mathrm{C}$ and ${}^{13}\mathrm{C}$($p,d$)${}^{12}\mathrm{C}$ reactions between 7 and 60 MeV to study the effect of inelastic couplings in transfer reactions. The effect of treating transfer beyond Born approximation is also addressed. The coupling to the ${}^{12}\mathrm{C}$ $2^{+}$ state is found to change the peak cross section by up to 15%. Effects beyond Born approximation lead to a significant renormalization of the cross sections, between 5% and 10% for deuteron energies above 10 MeV and larger than 10% for lower energies. We also performed calculations including the remnant term in the transfer operator, which has a small impact on the ${}^{12}\mathrm{C}$($d,p$)${}^{13}\mathrm{C}$(g.s.) and ${}^{13}\mathrm{C}$($p,d$)${}^{12}\mathrm{C}$(g.s.) reactions (where g.s. indicates ground state). Above 30-MeV deuteron energy, the effect of the remnant term is larger than 10% for the ${}^{12}\mathrm{C}$($d,p$)${}^{13}\mathrm{C}$($1/2^{+}$, 3.09 MeV) reaction and is found to increase with decreasing neutron separation energy for the 3.09-MeV state of ${}^{13}\mathrm{C}$. This is of importance for transfer reactions with weakly bound nuclei.

We present a new procedure that enables us to extract a scattering matrix $S\left(l\right)$ as a complex function of angular momentum directly from the scattering data without any a priori model assumptions implied. The key ingredient of the procedure is the evolutionary algorithm with diffused mutation that evolves the population of the scattering matrices by means of their smooth deformations from the primary arbitrary analytical $S\left(l\right)$ shapes to the final ones, giving high-quality fits to the data. Because of the automatic monitoring of the scattering-matrix derivatives, the final $S\left(l\right)$ shapes are monotonic and do not have any distortions. For the ${}^{16}\mathrm{O}$-${}^{16}\mathrm{O}$ elastic-scattering data at 350 MeV, we show the independence of the final results of the primary $S\left(l\right)$ shapes. Contrary to other approaches, our procedure provides an excellent fit by the $S\left(l\right)$ shapes that support the “rainbow” interpretation of the data under analysis.

The characteristics of the chiral phase transition are analyzed within the framework of chiral quark models with nonlocal interactions in the mean-field approximation. In the chiral limit, we develop a semianalytic framework that allows us to explicitly determine the phase transition curve, the position of the critical points, some relevant critical exponents, etc. For the case of finite current quark masses, we show the behavior of various thermodynamical and chiral response functions across the phase transition.

We reanalyze the most recent data on elastic electron-proton scattering. We look for deviation from linearity of the Rosenbluth fit to the differential cross section, which would be the signature of the presence of two-photon exchange. The two-photon contribution is parametrized by a one-parameter formula, based on symmetry arguments. The present data do not show evidence for such deviation.

The β decay of a neutron into a bound $({\mathit{pe}}^{-})$ state and an antineutrino in the presence of a strong uniform magnetic field ($B\gtrsim {10}^{13}$ G) is considered. The β decay process is treated within the framework of the standard model of weak interactions. A Bethe-Salpeter formalism is employed for description of the bound $({\mathit{pe}}^{-})$ system in a strong magnetic field. For the field strengths ${10}^{13}\lesssim B\lesssim {10}^{18}$ G the estimate for the ratio of the bound-state decay rate $w_b$ and the usual (continuum-state) decay rate $w_c$ is derived. It is found that in such strong magnetic fields $w_b/w_c~0.1\text{−}0.4$. This is in contrast to the field-free case, where $w_b/w_c\simeq 4.2\times {10}^{-6}$ [J. N. Bahcall, Phys. Rev. 124, 495 (1961); L. L. Nemenov, Sov. J. Nucl. Phys. 15, 582 (1972); X. Song, J. Phys. G: Nucl. Phys. 13, 1023 (1987)]. The dependence of the ratio $w_b/w_c$ on the magnetic field strength B exhibits a logarithmiclike behavior. The obtained results can be important for applications in astrophysics and cosmology.

In-target resonance ionization was applied for the first time, to our knowledge, for isotope-shift and hyperfine splitting measurements at the Investigation of Radioactive Isotopes on Synchrocyclotron (IRIS) facility. The production yield of the short-lived Gd atoms and the selectivity of the laser ionization appear to be nearly two and seven times higher, respectively, compared with those of a conventional target–laser-ion-source system. Changes in mean-square charge radii $\delta \langle r^2\rangle {}_{A,A^{\text{'}}}$ for ${}^{145}\mathrm{Gd}$,${}^{145}\mathrm{Gd}{}^m$, and ${}^{143}\mathrm{Gd}{}^m$ and magnetic moments for ${}^{145}\mathrm{Gd}$ and ${}^{143}\mathrm{Gd}{}^m$ are determined. The stabilization influence of the proton subshell closure on the $\delta \langle r^2\rangle {}_{A,A^{\text{'}}}$ (i.e., on the deformation) behavior at $N<82$ was not observed.

The analytical solution of the confined β-soft (CBS) rotor model is systematically compared to the energies of the ground-state rotational bands of strongly deformed heavy even-even nuclei. The model reproduces with one structural parameter the yrast band energies for all sufficiently well known rare-earth nuclei and actinides with a structural signature of $R_{4/2}=E(4_1^{+})/E(2_1^{+})>3.30$ up to the ${12}^{+}$ state with an accuracy of the order of ${10}^{-3}$. This systematic study of the CBS model demonstrates the regularity of the ground-state bands without exception. Comparison to the Davydov Chaban model suggests that the agreement between data and collective models with soft potentials is insensitive to the details of the potential.

Methodology is presented for analysis of two-particle azimuthal angle correlation functions obtained in collisions at ultrarelativistic energies. We show that harmonic and di-jet contributions to these correlation functions can be reliably decomposed by two techniques to give an accurate measurement of the jet-pair distribution. Results from detailed Monte Carlo simulations are used to demonstrate the efficacy of these techniques in the study of possible modifications to jet topologies in heavy ion reactions.

The influence of finite temperature on the antiferromagnetic (AFM) spin ordering in symmetric nuclear matter with the effective Gogny interaction is studied within the framework of a Fermi liquid formalism. It is shown that the AFM spin polarization parameter of partially polarized nuclear matter for low enough temperatures increases with temperature. The entropy of the AFM spin state for some temperature range is larger than the entropy of the normal state. Nevertheless, the free energy of the AFM spin state is always less than the free energy of the normal state and, hence, the AFM spin polarized state is preferable for all temperatures below the critical temperature.

A six-dimensional Davidson potential, introduced within the framework of the interacting vector boson model (IVBM), is used to describe nuclei that exhibit transitional spectra between the purely rotational and vibrational limits of the theory. The results are shown to relate to a new dynamical symmetry that starts with the $\mathrm{Sp}(12,R)\supset \mathrm{SU}(1,1)\times \mathrm{SO}(6)$ reduction. Exact solutions for the eigenstates of the model Hamiltonian in the basis defined by a convenient subgroup chain of $\mathrm{SO}(6)$ are obtained. A comparison of the theoretical results with experimental data for heavy nuclei with transitional spectra illustrates the applicability of the theory.

Isomeric cross-section ratio and excitation functions have been measured for ${}^{93}\mathrm{Nb}(\alpha ,2n){}^{95}\mathrm{Tc}{}^{m+g}$ reactions up to 120 MeV. The ratio and the excitation functions were interpreted in terms of the theoretical results obtained by two models COMPLET and STAPRE, which include preequilibrium effects. The experimental results were fairly well reproduced by the COMPLET calculations, which take into account the angular momentum removal in preequilibrium emission in an approximate way. Conversely, STAPRE calculations show a better agreement for isomeric ratio, but the experimental excitation function is underestimated by almost a factor of 2.

Spectroscopic factors (SFs) play an important role in nuclear physics and astrophysics. The traditional method of extracting SFs from direct transfer reactions suffers from serious ambiguities. We discuss a modified method that is based on including the asymptotic normalization coefficient of the overlap functions into the transfer analysis. In the modified method the contribution of the external part of the reaction amplitude, typically dominant, is fixed and the SF is determined from the fitting of the internal part. We illustrate the modified method with $(d,p)$ reactions on ${}^{208}\mathrm{Pb},{}^{12}\mathrm{C}$, and ${}^{84}\mathrm{Se}$ targets at different energies. The modified method allows one to extract the SFs, which do not depend on the shape of the single-particle nucleon-target interaction, and has the potential of improving the reliability and accuracy of the structure information. This is specially important for nuclei on dripline, where not much is known.

A possibility of extending the applicability range of nonrelativistic calculations of electronuclear response functions in the quasielasic peak region is studied. We show that adopting a particular model for determining the kinematic inputs of the nonrelativistic calculations can extend this range considerably, almost eliminating the reference frame dependence of the results. We also show that there exists one reference frame where essentially the same result can be obtained with no need of adopting the particular kinematic model. The calculation is carried out with the Argonne V18 potential and the Urbana IX three-nucleon interaction. A comparison of these improved calculations with experimental data shows a very good agreement for the quasielastic peak positions at $q=500,600,700\text{MeV}/c$ and for the peak heights at the two lower q values, while for the peak height at $q=700\text{MeV}/c$, one finds differences of about 20%.

A possible interpretation of the near-threshold enhancement in the $(p\overline{p})$ mass spectrum in $J/\psi \to \gamma p\overline{p}$ is the existence of a narrow baryonium resonance $X$(1860). Mesonic decays of the $(p\overline{p})$ bound state $X(1860)$ because of the nucleon-antinucleon annihilation are investigated in this article. Mesonic coherent states with fixed G parity and P parity have been constructed. The Amado-Cannata-Dedoder-Locher-Shao formulation is extended to the decays of the $X(1860)$. By this method, the branch-fraction ratios of $\mathrm{Br}(X\to \eta 4\pi ),\mathrm{Br}(X\to \eta 2\pi )$, and $\mathrm{Br}(X\to 3\eta )$ are calculated. It is shown that if the $X(1860)$ is a bound state of $(p\overline{p})$, the decay channel ($X\to \eta 4\pi )$ is favored over $(X\to \eta 2\pi )$. In this way, we develop criteria for distinguishing the baryonium interpretation for the near-threshold enhancement effects in the $(p\overline{p})$ mass spectrum in $J/\psi \to \gamma p\overline{p}$ from other possibilities. Experimental checks are expected. An intuitive picture for our results is discussed.

We calculate the density-dependent spin-isospin asymmetry energy $J(k_f)$ of nuclear matter in the three-loop approximation of chiral perturbation theory. The interaction contributions to $J(k_f)$ originate from one-pion exchange, iterated one-pion exchange, and irreducible two-pion exchange with no, single, and double virtual Δ-isobar excitation. We find that the approximation to $1\pi$-exchange and iterated $1\pi$-exchange terms (which leads already to a good nuclear matter equation of state by adjusting an emerging contact term) is spin-isospin stable, since $J(k_{f0})\simeq 24\mathrm{MeV}>0$. The inclusion of the chiral $\pi N\Delta$ dynamics, necessary in order to guarantee the spin stability of nuclear matter, keeps this property intact. The corresponding spin-isospin asymmetry energy $J(k_f)$ stays positive even for extreme values of an undetermined short-distance parameter $J_5$ (whose possible range we estimate from realistic NN potentials). The largest positive contribution to $J(k_f)$ (a term linear in density) comes from a two-body contact term with its strength fitted to the empirical nuclear matter saturation point.

The fission barriers as well as different fission paths of the ${}^{70}\mathrm{Se}$ nucleus have been microscopically investigated within a constrained Skyrme-Hartree-Fock plus BCS approach using the SkM${}^{*}$ effective interaction. The effects of intrinsic reflection asymmetric deformations have been taken into account while axial symmetry around the fission direction has been assumed. The two-body part of the center of mass correction has been included in a perturbative way and has been found to weakly contribute to the calculated barrier heights. Upper limits of the latter have been evaluated as the heights with respect to the ground state energy of the lowest saddle points obtained along continuous paths in a reasonably dimensioned collective space connecting one-body shaped and two-body shaped configurations. They have been found somewhat higher than what is expected from other theoretical studies.