Spectra of $p\text{−}p$ and $\pi \text{−}p$ scattering at beam momenta between 6 and 30 GeV/c have been reanalyzed. These show strong excitation of $N^{*}$ resonances, the strongest one corresponding to the “scalar” $P_{11}$ excitation (breathing mode) at $m_0=1400\pm 10\text{MeV}$ with $\Gamma =200\pm 20\text{MeV}$. The result of a strong scalar excitation is supported by a large longitudinal amplitude $S_{1/2}$ extracted from $e\text{−}p$ scattering. From exclusive data on $p+p\to \mathit{pp}{\pi }^{+}{\pi }^{-}$, a large $2\pi \text{−}N$ decay branch for the $P_{11}$ resonance of $B_{2\pi }=75\pm 20$% has been extracted.

The differential cross sections were described in a double-folding approach, assuming multigluon exchange as the dominant part of the effective interaction between the constituents of projectile and target. First, the parameters of the interaction were fitted to elastic scattering; then, with this interaction, the inelastic cross sections were described in the distorted wave Born approximation (DWBA). A good description of the data requires a surface peaked transition density, quite different from that of a pure radial mode. In contrast, the electron scattering amplitude $S_{1/2}$ is quite well described by a breathing mode transition density with radial node. This large difference between charge and matter transition densities suggests that in $p\text{−}p$ scattering the coupling to the multigluon field is much more important than the coupling to the valence quarks. A multigluon (or sea-quark) transition density is derived, which also shows breathing, indicating a rather complex multiquark structure of N and $N^{*}$ including additional multigluon (or $q^{2n}{\overline{q}}^{2n}$) creation out of the ground state vacuum.

The axial-vector Ward-Takahashi identity places constraints on particular properties of every pseudoscalar meson. For example, in the chiral limit all pseudoscalar mesons, except the Goldstone mode, decouple from the axial-vector current. Nevertheless, all neutral pseudoscalar mesons couple to two photons. The strength of the ${\pi }_n^0\gamma \gamma$ coupling, where $n=0$ denotes the Goldstone mode, is affected by the Abelian anomaly's continuum contribution. The effect is material for $n\ne 0$. The ${\gamma }^{*}{\pi }_n{\gamma }^{*}$ transition form factor, ${\mathcal{T}}_{{\pi }_n}(Q^2)$, is nonzero $\forall n$, and ${\mathcal{T}}_{{\pi }_n}(Q^2)\approx (4{\pi }^2/3)(f_{{\pi }_n}/Q^2)$ at large $Q^2$. For all pseudoscalars but the Goldstone mode, this leading contribution vanishes in the chiral limit. In this instance the ultraviolet power-law behavior is $1/Q^4$ for $n\ne 0$, and we find numerically ${\mathcal{T}}_{{\pi }_1}(Q^2)\simeq (4{\pi }^2/3)(-\langle \overline{q}q\rangle /Q^4)$. This subleading power-law behavior is always present. In general its coefficient is not simply related to $f_{{\pi }_n}$. The properties of $n\ne 0$ pseudoscalar mesons are sensitive to the pointwise behavior of the long-range piece of the interaction between light quarks.

We have modeled the parton distribution in nuclei using a suitably modified nuclear Fermi motion. The modifications concern the nucleon rest energy which changes the Björken x in a nuclear medium. We also introduce final state interactions between the scattered nucleon and the rest of the nucleus. The energy-momentum sum rule is saturated. Good agreement with experimental data of the EMC effect for $x>0.15$ and nuclear lepton pair production data has been obtained.

The most commonly accepted interpretation of the light Pt isotopes invokes the coexistence and mixing with proton intruder states from above the Z = 82 shell gap. Using an alternative description, interacting boson model (IBA) calculations are performed for the Pt isotopes with a simple, single configuration, two-parameter Hamiltonian. Excellent agreement is obtained for energies and electromagnetic transition strengths over the entire isotopic chain, spanning a wide variety of structures, and suggesting that these nuclei can be described more simply without the introduction of an intruder configuration. The Pt nuclei close to midshell are found to lie close to a region of phase/shape coexistence.

Two independent calculations of proton-deuteron elastic scattering observables including Coulomb repulsion between the two protons are compared in the proton laboratory energy region between 3 and 65 MeV. The hadron dynamics is based on the purely nucleonic charge-dependent AV18 potential. Calculations are done in both coordinate space and momentum space. The coordinate-space calculations are based on a variational solution of the three-body Schrödinger equation using a correlated hyperspherical expansion for the wave function. The momentum-space calculations proceed via the solution of the Alt-Grassberger-Sandhas equation using the screened Coulomb potential and the renormalization approach. Both methods agree to the order of 1% on all observables, showing the reliability of both numerical techniques in that energy domain. At energies below the three-body breakup threshold, the coordinate-space method remains favored; at energies higher than 65 MeV, the momentum-space approach seems to be more efficient.

The recent experimental observation of collective rotational bands up to $I>60\hslash$ in ${}^{175}\mathrm{Hf}$ presents theoretical challenges. It is shown here that total Routhian surface calculations are able to explain the yrast high-spin behavior, with collective oblate states favored at $I~35\hslash$ and strongly deformed prolate states at the highest spins. The collective oblate rotation terminates in noncollective prolate states. Comparisons are made with ultimate cranker calculations, and theoretical quadrupole moments are evaluated.

We have investigated negative-parity $\mathit{uudd}\overline{s}$ pentaquarks by employing a quark model with the meson exchange and the effective gluon exchange as qq and $q\overline{q}$ interactions. The system of five quarks is dynamically solved; the qq and $q\overline{q}$ correlations are taken into account in the wave function. The masses of the pentaquarks are found to be reasonably low. It is found that the lowest-mass state is $T{J}^P=0{\frac{1}{2}}^{-}$ and the next lowest one is $0{\frac{3}{2}}^{-}$. The former is reported to have a large width. We argue that the observed narrow peak corresponds to the latter state. It is still necessary to introduce an extra attraction to reduce the mass further by 140–280 MeV to reproduce the observed ${\Theta }^{+}$ mass. Since their level splitting is less than 80 MeV, the lower level will not become a bound state below the NK threshold even after such an attraction is introduced. It is also found that the relative distance of two quarks with the attractive interaction is found to be by about 1.2–1.3 times closer than that of the repulsive one. The two-body correlation seems important in the pentaquark systems.

The S-wave $\Lambda K$ and $\Sigma K$ states with isospin $I=1/2$ are dynamically investigated within the framework of the chiral SU(3) quark model by solving a resonating group method equation. The model parameters are taken from our previous work, which gave a good description of the energies of the baryon ground states, the binding energy of the deuteron, and the experimental data of the nucleon-nucleon (NN) and nucleon-hyperon (NY) scattering. Assumed not to give important contributions in the scattering processes, the s-channel quark-antiquark ($q\overline{q}$) annihilation interactions are not included as a first step. The results show a strong attraction between Σ and K, which consequently results in a $\Sigma K$ quasibound state with about 17-MeV binding energy, unlike the case of $\Lambda K$, which is unbound. When the channel coupling of $\Lambda K$ and $\Sigma K$ is considered, a sharp resonance state near 1670 MeV with spin-parity $J^P=1/2^{-}$ is found. The narrow gap of the $\Lambda K$ and $\Sigma K$ thresholds, the strong attraction between Σ and K, and the sizable off-diagonal matrix elements of $\Lambda K$ and $\Sigma K$ are responsible for the appearance of this resonance.

We consider the relationship between p-wave $\pi N$ scattering and the strength of the p-wave two-pion-exchange three-nucleon interaction (TPE3NI). We explain why effective theories that do not contain the Delta resonance as an explicit degree of freedom tend to overestimate the strength of the TPE3NI. The overestimation can be remedied by higher-order terms in these “Delta-less” theories, but such terms are not yet included in state-of-the-art chiral effective field theory calculations of the nuclear force. This suggests that these calculations can predict the strength of the TPE3NI only to an accuracy of $\pm 25$%.

We perform calculations for the production of ϕ mesons in nuclei at energies just above threshold and study the A dependence of the cross section. We use results for the ϕ self-energy in the medium obtained within a chiral unitary approach. We find a strong A dependence which is tied to the distortion of the incident proton and to the absorption of the ϕ on its way out of the nucleus. The effect of this latter process reduces the cross section by about a factor of 2 in heavy nuclei, proving that the A dependence of the cross section bears valuable information on the ϕ width in the nuclear medium. Calculations are done for energies accessible in an experimental facility like COSY.

Excited states in neutron-rich ${}^{187}\mathrm{W}$ have been populated via deep inelastic collisions of a 630-MeV ${}^{82}\mathrm{Se}$ beam on a ${}^{186}\mathrm{W}$ target. Projectilelike fragments were measured by an annular Si detector for reaction channel selection. Delayed γ rays from target residues were detected by means of the so-called recoil shadow technique. A new isomer at 411 keV, based on the $11/2^{+}$[615] Nilsson configuration, has been identified with a half-life of 1.55(13) μs. The decay rates of the isomers are discussed in terms of the K quantum number by comparison with the systematics from neighboring nuclei.

The new neutron-rich rare-earth isotopes ${}^{159}\mathrm{Pm}$, ${}^{162}\mathrm{Sm}$, and ${}^{166}\mathrm{Gd}$ produced in the proton-induced fission of ${}^{238}\mathrm{U}$ were identified using the JAERI on-line isotope separator (JAERI-ISOL) coupled to a gas-jet transport system. The half-lives of ${}^{159}\mathrm{Pm}$, ${}^{162}\mathrm{Sm}$, and ${}^{166}\mathrm{Gd}$ were determined to be 1.5 ± 0.2, 2.4 ± 0.5, and 4.8 ± 1.0 s respectively. The partial decay scheme of ${}^{166}\mathrm{Gd}$ was constructed from $\gamma \gamma$-coincidence data. A more accurate half-life value of 25.6 ± 2.2 s was obtained for the previously identified isotope ${}^{166}\mathrm{Tb}$. The half-lives measured in the present study are in good agreement with the theoretical predictions calculated by the second generation of the gross theory with the atomic masses evaluated by Audi and Wapstra.

We propose a simple model to describe cluster-shell competition. Introducing only one parameter (Λ) to the wave function makes it possible to describe the asymptotic transition of two valence neutrons in ${}^{10}\mathrm{Be}$ ($\alpha +\alpha +n+n$) from a di-neutron to independent particles when the contribution of the spin-orbit interaction is taken into account. Similarly in ${}^{12}\mathrm{C}$, a transition from a 3α configuration to a $2\alpha +4N$ configuration is represented, and we show a strong contribution of the spin-orbit interaction in the ground state. We investigate further this transition from the cluster state ($\alpha +{}^{16}\mathrm{O}$) to the shell-model state (${}^{16}\mathrm{O}$ + four nucleons) in ${}^{20}\mathrm{Ne}$. In these examples, the wave functions for cluster-breaking states are prepared in the same general way.

A systematic study of the total β-decay half-lives and β-delayed neutron emission probabilities is performed. The β-strength function is treated within a self-consistent density-functional + continuum-quasiparticle-random-phase-approximation framework including the Gamow-Teller and first-forbidden transitions. The experimental total β-decay half-lives for the Ni isotopes with $A\le 76$ are described satisfactorily. The half-lives predicted from $A=70$ up to $A=86$ reveal fairly regular A behavior which results from simultaneous account for the Gamow-Teller and first-forbidden transitions. For $Z\approx 28$ nuclei, a suppression of the delayed neutron emission probability is found when the $N=50$ neutron closed shell is crossed and the neutron excess becomes more than one major shell. The effect originates from the high-energy first-forbidden transitions to the states outside the $Q_{\beta }\text{−}{B}_n$ window in the daughter nuclei.

We discuss the one-body potentials for protons and neutrons obtained from Dirac-Brueckner-Hartree-Fock calculations of neutron-rich matter, in particular their dependence upon the degree of proton/neutron asymmetry. The closely related symmetry potential is compared with empirical information from the isovector component of the nuclear optical potential.

Local scale transformations are made to vary the long-range properties of harmonic oscillator orbitals conventionally used in model structure calculations of nuclear systems. The transformations ensure that those oscillator states asymptotically have exponentially decaying forms consistent with a set of chosen single-nucleon energies, leaving the structure essentially unchanged within the body of the nucleus. Application has been made to the radioactive nuclei ${}^{6,8}\mathrm{He}$ and ${}^{11}\mathrm{Li}$, and the resulting wave functions are used to generate g-folding optical potentials for elastic scattering of those ions from hydrogen. As a consistency test, application has been made to form wave functions for ${}^{40}\mathrm{Ca}$, and they have been used also to specify relevant proton-${}^{40}\mathrm{Ca}$ optical potentials with which elastic scattering has been predicted.

A new evaluation of the $\pi N\Sigma$ term is presented that incorporates recent s-channel phase shifts and t-channel $\pi \pi$ phase shifts. We also introduce analyticity-based extrapolation techniques that, along with standard dispersion relation methods, produce a more reliable extrapolation to the Cheng-Dashen point. A recent George Washington University (GWU) phase-shift analysis leads to a Σ term of $81\pm 6\text{MeV}$.

The so-called semirelativistic expansion of the weakly charged current in powers of the initial nucleon momentum is performed to describe charge-changing, quasielastic neutrino reactions $({\nu }_{\mu },{\mu }^{-})$ at intermediate energies. The quality of the expansion is tested by comparing it with the relativistic Fermi gas model using several choices of kinematics of interest for ongoing neutrino oscillation experiments. The new current is then implemented in a continuum shell model together with relativistic kinematics to investigate the scaling properties of $(e,e^{\text{'}})$ and $({\nu }_{\mu },{\mu }^{-})$ cross sections.

In Eqs. (43) and (44), the factor $(1+{\alpha }_0{\overline{J}}_3){}^{-\frac{1}{2}}$ should be replaced by $(1+{\alpha }_2{\overline{J}}_3){}^{-\frac{1}{2}}$. Similarly, in Eqs. (46) and (47), the factor $(1+q_3{\alpha }_{0}M{\mu }^3){}^{-\frac{1}{2}}$ should be replaced by $(1+q_3{\alpha }_{2}M{\mu }^3){}^{-\frac{1}{2}}$. The results and conclusions of the article are not affected.

We estimate the decrease of the Coulomb-barrier height between colliding partners due to charge polarizations in the entrance channel for cold-fusion reactions. The resulting charge displacements between protons and neutrons are the sum of the surface- and volume-charge components. We show the difference between the charge polarization of light and heavy nuclei and the decrease of the Coulomb barrier height for synthesizing superheavy elements.