$p\Lambda$ emission in coincidence following $K^{-}$ absorption at rest in nuclei is studied using quantum-mechanical scattering theory and nuclear wave functions. $K^{-}$ absorption is assumed to occur on two protons in the nucleus. In the formalism, emphasis is put on the study of the final state interaction (FSI) effects of $p$ and $\Lambda$ with the recoiling nucleus. We include elastic scattering and single-nucleon knock-out (KO) channels in the FSI. Calculations are presented for the ${}^{12}\mathrm{C}$ nucleus, using shell-model wave functions, and without any extra mass modification of the $K^{-}\mathit{pp}$ system in the nucleus. Calculated results are presented for the angular correlation distribution between $p$ and $\Lambda$, their invariant mass distribution, and the momentum spectra of $p$ and $\Lambda$. These results are compared with the corresponding experimental measurements of M. Agnello et al., [Phys. Rev. Lett. 94, 212303 (2005)]. With only elastic scattering FSI included, the angular correlation distribution and the momentum spectra are found to be in good accord with the corresponding measurements. With full FSI, the calculated $p\Lambda$ invariant mass distribution is found to have two peaks, one corresponding to the elastic scattering FSI and another to single-nucleon KO FSI. The KO peak agrees fully, in position and shape, with the peak observed by M. Agnello et al. The peak corresponding to elastic scattering FSI does not seem to exist in the measured distribution. Considering that such a two-peak structure is always seen in the inclusive ($p,p^{\prime }$) and ($e,e^{\prime }$) reactions in nuclei at intermediate energies, absence of the elastic scattering peak in the $p\Lambda$ reaction is intriguing.

A chiral constituent quark model approach, embodying $s$- and $u$-channel exchanges, complemented with a Reggeized treatment for the $t$ channel is presented. A model is obtained allowing data for ${\pi }^{-}p\to \eta n$ and $\gamma p\to \eta p$ to be described satisfactorily. For the latter reaction, recently released data by the CLAS and CBELSA/TAPS Collaborations in the system total energy range $1.6\lesssim W\lesssim 2.8$ GeV are well reproduced by the inclusion of Reggeized trajectories instead of simple $\rho$ and $\omega$ poles. The contribution from “missing” resonances, with masses below 2 GeV, is found to be negligible in the considered processes.

We present a study of neutrino-nucleus interactions at the T2K experiment based on the GiBUU transport model. The aim of T2K is to measure ${\nu }_e$ appearance and ${\theta }_{13}$, but it will also be able to do a precise measurement of ${\nu }_{\mu }$ disappearance. The former requires a good understanding of ${\pi }^0$ production, while the latter is closely connected with a good understanding of quasielastic scattering. For both processes we investigate the influence of nuclear effects and particular final-state interactions on the expected event rates, taking into account the T2K detector setup.

The proton-neutron interaction in determining the evolution of nuclear structure has been studied by using the Brillouin-Wigner perturbation expansion. The particle-hole and particle-particle $p$-$n$ interactions are unifiedly described in the theory. The obtained formulas of level energies and excitation energies scaled in the small- and large-$N_p{N}_n$ limits can well explain the linearity of the extracted proton-neutron interaction energies and the attenuation of the $2_1^{+}$ excitation energies against the valence nucleon product $N_p{N}_n$for five mass regions from $A=100–200$.

We study the $K\Lambda (1405)$ configuration of the $K\mathrm{K̄}N$ system by considering $K\pi \Sigma$ as a coupled channel. We solve the Faddeev equations for these systems and find confirmation of the existence of a new $N^{*}$ resonance around 1920 MeV, with $J^{\pi }=1/2^{+}$ predicted in a single-channel potential model and also found in a Faddeev calculation as an $a_0(980)N$ state, with the $a_0(980)$ generated in the $K\mathrm{K̄}$, $\pi \eta$ interaction.

A three-quasiparticle isomer with $\tau =170(8)$ $\mu$s and $K^{\pi }=$ ($19/2^{+}$) has been identified in the neutron-rich isotope ${}^{169}\mathrm{Ho}$. The isomer decays with $K$-forbidden transitions to members of a band associated with the $7/2^{-}$[523] proton configuration, whose structure is characterized through analysis of the in-band $\gamma$-ray branching ratios. In the isotone ${}^{171}\mathrm{Tm}$, the rotational band based on the known $19/2^{+}$, three-quasiparticle isomer has also been observed. Alternative one-proton two-neutron configurations for the isomer in ${}^{169}\mathrm{Ho}$ are discussed in terms of multiquasiparticle calculations and through a comparison with the structures observed in ${}^{171}\mathrm{Tm}$.

Low-spin excited states of ${}^{140}\mathrm{Nd}$ have been studied via the ${}^{140}\mathrm{Ce}$(${}^3\mathrm{He}$,$3n$)${}^{140}\mathrm{Nd}$ reaction. The data show that one of the candidates for the one-phonon mixed-symmetry state (MSS) of ${}^{140}\mathrm{Nd}$, namely, the $2_3^{+}$ state at 2140 keV with an effective lifetime of 220(90) fs, exhibits a fast $M1$ decay to the $2_1^{+}$ state. Thus, this state can be considered, at least, as a fragment of the one-phonon MSS of ${}^{140}\mathrm{Nd}$. This is the first example where mixed symmetry character is tentatively assigned to a state of an unstable nucleus from the mass $A\approx 140$ region based on the data on absolute $M1$ transition rates. However, the data are not conclusive on whether this decay exhausts the total $M1$ strength or whether the one-phonon MSS of ${}^{140}\mathrm{Nd}$ is fragmented.

The dead-cone effect has been predicted to reduce the magnitude of energy loss and jet quenching for heavy flavors produced with large $p_T$ in heavy-ion collisions. On the contrary, data from the Relativistic Heavy Ion Collider demonstrate a strong suppression of high-$p_T$ electrons from charm and bottom decays. We show that vacuum radiation of a highly virtual quark produced at high $p_T$ with a stripped-off color field develops a much wider dead cone, which screens the one related to the quark mass. Lacking the field, gluons cannot be radiated within this cone until the color field is regenerated and the quark virtuality cools down to the scale of the order of the quark mass. However, this takes longer than is essential for the observed jet quenching, leading to similar nuclear effects for the light and charm quark jets. Open beauty is expected to radiate much less within the $p_T$ range studied so far in heavy-ion collisions.

The extended vector meson dominance model, which allows one to describe the electromagnetic form factors of nucleons obeying the asymptotic quark counting rule prescriptions and contains the minimal number of free parameters, is presented. We obtain a reasonable fit of form factors over the experimentally available spacelike region of momentum transfer and reasonable results in the timelike region.

The Woods-Saxon-Strutinsky method (the microscopic-macroscopic method) combined with the Kruppa prescription for positive-energy levels, which is necessary to treat neutron-rich nuclei, is studied to clarify the reason for its success and to propose improvements for its shortcomings. The reason why the plateau condition is met for the Nilsson model but not for the Woods-Saxon model is understood in a new interpretation of the Strutinsky smoothing procedure as a low-pass filter. Essential features of the Kruppa level density is extracted in terms of the Thomas-Fermi approximation modified to describe spectra obtained from diagonalization in truncated oscillator bases. A method is proposed, which weakens the dependence on the smoothing width by applying the Strutinsky smoothing only to the deviations from a reference level density. The BCS equations are modified for the Kruppa spectrum, which is necessary to treat the pairing correlation properly in the presence of a continuum. The potential depth is adjusted for the consistency between the microscopic and macroscopic Fermi energies. It is shown, with these improvements, that the microscopic-macroscopic method is now capable to reliably calculate binding energies of nuclei far from stability.

A recent measurement of the ${}^{11}\mathrm{Be}+{}^{64}\mathrm{Zn}$ quasielastic scattering angular distribution exhibits a non-Fresnel-type pattern, in contrast to ${}^6\mathrm{He}+{}^{64}\mathrm{Zn}$ elastic scattering but similar to that for the elastic scattering of ${}^6\mathrm{He}$ from heavy targets. We show by means of continuum discretized coupled-channels (CDCC) calculations that this unusual behavior of ${}^{11}\mathrm{Be}$ is caused by the much greater importance of nuclear coupling to the continuum in ${}^{11}\mathrm{Be}$ compared to ${}^6\mathrm{He}$, where Coulomb dipole coupling is mainly responsible for the non-Fresnel-like shape, when present. We also show that the dynamic polarization potentials derived from the CDCC calculations seem to follow a universal form as a function of radius.

Fast induced decay of the long-lived nuclear isomer ${}^{178}\mathrm{Hf}$${}^{m2}$ via an intermediate state is shown to be possible in a deuterium-tritium laser thermonuclear plasma as a result of inelastic scattering of $\alpha$ particles and fast electrons on isomeric nuclei. A similar phenomenon also takes place in deuterium-deuterium plasma, where the intermediate state is exited by protons, thermal electrons, and photons.

We measured the half-life of the superallowed $0^{+}\to 0^{+}$ ${\beta }^{+}$ emitter ${}^{26}\mathrm{Si}$ to be $2245.3(7)$ ms. We used pure sources of  ${}^{26}\mathrm{Si}$ and employed a high-efficiency gas counter, which was sensitive to positrons from both this nuclide and its daughter ${}^{26}\mathrm{Al}$${}^m$. The data were analyzed as a linked parent-daughter decay. To contribute meaningfully to any test of the unitarity of the Cabibbo-Kobayashi-Maskawa (CKM) matrix, the $\mathit{ft}$ value of a superallowed transition must be determined to a precision of $0.1\%$ or better. With a precision of $0.03\%$, the present result is more than sufficient to be compatible with that requirement. Only the branching ratio now remains to be measured precisely before a $\pm 0.1\%$ $\mathit{ft}$ value can be obtained for the superallowed transition from ${}^{26}\mathrm{Si}$.

High-spin states in the odd-odd nucleus ${}^{168}\mathrm{Ta}$ have been populated in the ${}^{120}\mathrm{Sn}$(${}^{51}\mathrm{V}$,3$n$) reaction. Two multi-quasiparticle structures have been extended significantly from spin $~20\hslash$ to above $40\hslash$. As a result, the first rotational alignment has been fully delineated and a second band crossing has been observed for the first time in this nucleus. Configurations for these strongly coupled rotational bands are proposed based on signature splitting, $B(M1)/B(E2)$ ratio information, and observed rotation-alignment behavior. Properties of the observed bands in ${}^{168}\mathrm{Ta}$ are compared to related structures in the neighboring odd-$Z$, odd-$N$, and odd-odd nuclei and are discussed within the framework of the cranked shell model.

The energy and angular dependence of double differential cross sections $d^2\sigma /d\Omega \mathit{dE}$ were measured for $p,d,t$, ${}^{3,4,6}\mathrm{He}$, ${}^{6,7,8}\mathrm{Li}$, ${}^{7,9,10}\mathrm{Be}$, ${}^{10,11}\mathrm{B}$, and C produced in collisions of 1.2, 1.9, and 2.5 GeV protons with a Ni target. The shape of the spectra and angular distributions almost does not change whereas the absolute value of the cross sections increases by a factor $~$1.7 for all ejectiles in this beam energy range. It was found that energy and angular dependencies of the cross sections cannot be reproduced by microscopic models of intranuclear cascade including coalescence of nucleons coupled to statistical model for evaporation of particles from excited, equilibrated residual nuclei. The inclusion of nonequilibrium processes, described by a phenomenological model of the emission from fast and hot moving sources, resulting from break up of the target nucleus, leads to very good reproduction of data. Cross sections of these processes are quite large, exhausting approximately half of the total production cross sections. Due to good reproduction of energy and angular dependencies of $d^2\sigma /d\Omega \mathit{dE}$ it was possible to determine total production cross sections for all studied ejectiles. Results obtained in this work point to the analogous reaction mechanism for proton induced reactions on Ni target as that observed previously for Au target in the same beam energy range.

A next-to-leading order QCD calculation of non-singlet spin structure function, $g_1^{\mathrm{NS}}$ is presented within the valon representation of hadrons. In the valon model, it is assumed that a nucleon is composed of three dressed valence quarks: the valons. Each valon has its own internal structure, the valence quark with its associated sea quarks and gluons. The results are in good agreement with all available data from SMC, E143, HERMES, and with the newly released data from COMPASS experiments. It appears that the small-$x$ tail of $g_1^{\mathrm{NS}}$ can be described by a single Regge-type exchange. The relevant parameter of this exchange is given. Finally we show that the polarized proton structure function has a scaling behavior at small $x$. The relevant parameters of this behavior are given, too.

This paper is dedicated to the study of even-even ${}^{8-14}\mathrm{Be}$ isotopes, which uses the particle-particle random-phase approximation that accounts for two-body correlations in the core nucleus. A better description of energies and two-particle amplitudes is obtained in comparison with models that assume a neutron closed-shell (or subshell) core. A Woods-Saxon potential corrected by a phenomenological particle-vibration coupling term has been used for the neutron-core interaction and the D1S Gogny force for the neutron-neutron interaction. Calculated ground-state properties as well as excited-state ones are discussed and are compared to experimental data. In particular, results suggest the same $2s_{1/2}-1p_{1/2}$ shell inversion in ${}^{13}\mathrm{Be}$ as in ${}^{11}\mathrm{Be}$.

Cooper pair sizes are evaluated in a simple harmonic oscillator model reproducing the values of sophisticated Hartree-Fock-Bogoliubov calculations. Underlying reasons for the very small sizes of 2.0–2.5 fm of Cooper pairs in the surface of nuclei are analyzed. It is shown that the confining properties of the nuclear volume is the dominating effect. It is argued that for Cooper pair sizes the local-density approximation idea is particularly inadapted.

The reported data are given for the mean angles measured rather than for the central angles. The data are normalized to the most recent Evaluated Nuclear Data File evaluated angle-integrated elastic-scattering cross section and refitted with a Legendre polynomial expansion.

Extending the Kruppa’s prescription for the continuum level density, we have recently improved the BCS method with seniority-type pairing force in such a way that the effects of discretized unbound states are properly taken into account for finite depth single-particle potentials. In this paper, it is further shown, by employing the Woods-Saxon potential, that the calculation of spatial observables, such as nuclear radius, converges as increasing the basis size in the harmonic oscillator expansion. Namely the disastrous problem of a “particle gas” surrounding nucleus in the BCS treatment can be circumvented. In spite of its simplicity, the new treatment gives similar results to those by more elaborate Hartree-Fock-Bogoliubov calculations, e.g., it even mimics the pairing antihalo effect. The obtained results as well as the reason of convergence in the new method are investigated by a variant of the Thomas-Fermi approximation within the limited phase space which corresponds to the harmonic oscillator basis truncation.