A comparison between full few-body Faddeev/Alt-Grassberger-Sandhas (Faddeev/AGS) and continuum-discretized coupled-channels calculations is made for the resonant and nonresonant breakup of ${}^{11}\mathrm{Be}$ on proton target at 63.7 MeV/u incident energy. A simplified two-body model is used for ${}^{11}\mathrm{Be}$ which involves an inert ${}^{10}\mathrm{Be}$($0^{+}$) core and a valence neutron. The sensitivity of the calculated observables to the nucleon-nucleon potential dynamical input is analyzed. We show that with the present $\mathit{NN}$ and $N$-core dynamics the results remain a puzzle for the few-body problem of scattering from light exotic halo nuclei.

The potential energy surfaces of even-even ${}^{146–156}\mathrm{Sm}$ are investigated in the constrained reflection-asymmetric relativistic mean-field approach with parameter set PK1. It is shown that the critical-point candidate nucleus ${}^{152}\mathrm{Sm}$ marks the shape/phase transition not only from $U(5)$ to $\mathit{SU}(3)$ symmetry, but also from the octupole-deformed ground state in ${}^{150}\mathrm{Sm}$ to the quadrupole-deformed ground state in ${}^{154}\mathrm{Sm}$. By including the octupole degree of freedom, an energy gap near the Fermi surface for single-particle levels in ${}^{152}\mathrm{Sm}$ with ${\beta }_2=0.14~0.26$ is found and the important role of the octupole deformation driving pair $\nu 2f_{7/2}$ and $\nu 1i_{13/2}$ is demonstrated.

High-spin states in the neutron-deficient nucleus ${}^{107}\mathrm{In}$ were studied via the ${}^{58}\mathrm{Ni}$(${}^{52}\mathrm{Cr}$,3p) reaction. In-beam $\gamma$ rays were measured using the JUROGAM detector array. A rotational cascade consisting of ten $\gamma$-ray transitions, which decays to the 19/$2^{+}$ level at 2.002 MeV, was observed. The band exhibits the features typical for smooth terminating bands that also appear in rotational bands of heavier nuclei in the $A\hspace{0.5em}~$ 100 region. The results are compared with total Routhian surface and cranked Nilsson-Strutinsky calculations.

Isomeric low-lying states were identified and investigated in the ${}^{75}\mathrm{Cu}$ nucleus. Two states at $61.8(5)$- and $128.3(7)$-keV excitation energies with half-lives of $370(40)$- and $170(15)$-ns were assigned as ${}^{75m1}\mathrm{Cu}$ and ${}^{75m2}\mathrm{Cu}$, respectively. The measured half-lives combined with the recent spin assignment of the ground state allow one to deduce tentatively spin and parity of the two isomers and the dominant multipolarities of the isomeric transitions with respect to the systematics of the Cu isotopes. Shell-model calculations using an up-to-date effective interaction reproduce the evolution of the $1/2^{-}$, $3/2^{-}$, and $5/2^{-}$ states for the neutron-rich odd-mass Cu isotopes when filling the $\nu g_{9/2}$. The results indicate a significant change in the nuclear structure in this region, where a single-particle $5/2^{-}$ state coexists with more and more collective $3/2^{-}$ and $1/2^{-}$ levels at low excitation energies.

Dense hadronic matter at low temperatures is expected to be in a crystalline state and at high density to make a transition to a chirally restored but color-confined state, which is a novel phase hitherto unexplored. This phase transition is predicted in both skyrmion matter in four dimensions and instanton matter in five dimensions, the former in the form of half-skyrmions and the latter in the form of half-instantons or dyons. We predict that when $K^{-}$’s are embedded in this half-skyrmion or half-instanton (dyonic) matter, which may be reached not far past the normal density, there arises an enhanced attraction from both the soft dilaton field figuring for the trace anomaly of QCD and the Wess-Zumino term. This attraction may have relevance for a possible strong binding of antikaons in dense nuclear matter and for kaon condensation in neutron-star matter. Such kaon property in the half-skyrmion phase is highly nonperturbative and may not be accessible by low-order chiral perturbation theory. Relevance of the half-skyrmion or dyonic matter to compact stars is discussed.

Based on experimental evidence from the ${}^{144}\mathrm{Sm}$($\alpha ,2n$) reaction, the $3484.7$-keV $6^{+}$ state in ${}^{146}\mathrm{Gd}$ is identified as the highest-spin member of the $3^{-}\otimes 3^{-}$ two-phonon octupole quartet. A previously unknown $\gamma$ line of $1905.8$ keV and $E3$ character feeding the $3^{-}$ octupole state has been observed. These results represent the first observation of a $6^{+}\to 3^{-}\to 0^{+}$ cascade of two $E3$ transitions in an even-even nucleus and provide strong support for the interpretation of the $6^{+}$ state as a two-phonon octupole excitation.

Aligned fragment emission associated with peripheral and midperipheral dissipative collisions of ${}^{124}\mathrm{Xe}$$+$${}^{124}\mathrm{Sn}$ at $E/A=50$ MeV is examined. Binary decay of the excited projectile-like fragment (PLF${}^{*}$) is correlated with significant velocity damping from the projectile velocity. Both a forward emission component, attributed to standard statistical emission, and a backward component are observed. The backward component arises from both statistical and dynamical decay processes. This backward component manifests a strong alignment with the direction of the PLF${}^{*}$ velocity and is found to depend sensitively on the atomic number of the light fragment, $Z_L$, and the velocity of the PLF${}^{*}$. The yield of the backward component is significantly enhanced relative to the forward component. The composition of fragments emitted in the backward direction reveals that a correlation between alignment and neutron excess exists for fragments with $Z<8$. From the measured asymmetry of the angular distributions, the angular distribution for dynamical fragment emission is deduced. Comparison with a schematic one-dimensional Langevin model allows extraction of both the magnitude and the dependence on $Z_L$ of the transient initial deformation of the PLF${}^{*}$. Fragment emission times of the order of $0.25–1.5\times {10}^{-21}$ s are extracted.

The nuclear–mass dependence of azimuthal cross-section asymmetries with respect to charge and longitudinal polarization of the lepton beam is studied for hard exclusive electroproduction of real photons. The observed beam-charge and beam-helicity asymmetries are attributed to the interference between the Bethe-Heitler and the deeply virtual Compton scattering processes. For various nuclei, the asymmetries are extracted for both coherent and incoherent-enriched regions, which involve different (combinations of) generalized parton distributions. For both regions, the asymmetries are compared to those for a free proton, and no nuclear-mass dependence is found.

In this Rapid Communication we discuss some observations concerning the possible local parity violation in heavy ion collisions recently announced by the STAR Collaboration. Our results can be summarized as follows (i) the measured correlations for same-charge pairs are mainly in-plane and not out of plane, (ii) if there is a parity-violating component it is large and surprisingly of the same magnitude as the background, and (iii) the observed dependence of the signal on the transverse momentum ($p_t$) is consistent with a soft boost in $p_t$ and thus in line with expectations from the proposed chiral magnetic effect.

A zone of reactions is determined and then exploited as a tool in studying the space-time structure of an interacting system formed in a collision of relativistic nuclei. The time dependence of the reaction rates integrated over spatial coordinates is also considered. Evaluations are made with the help of the microscopic transport model UrQMD. The relation of the boundaries of different zones of reactions and the hypersurfaces of sharp chemical and kinetic freeze-outs is discussed.

The transverse electron scattering response function of ${}^3\mathrm{He}$ is studied in the quasielastic peak region for momentum transfers between 500 and 700 MeV/$c$. A conventional description of the process leads to results that vary substantially from experiment. To improve the results, the present calculation is done in a reference frame [the active nucleon Breit (ANB) frame] that diminishes the influence of relativistic effects on nuclear states. The laboratory frame response function is then obtained via a kinematics transformation. In addition, a one-body nuclear current operator is employed that includes all leading-order relativistic corrections. Multipoles of this operator are listed. It is shown that the use of the ANB frame leads to a sizable shift in the quasielastic peak to lower energy and, contrary to the relativistic current, also to an increase in the peak height. The additionally considered meson exchange current contribution is quite small in the peak region. In comparison with experiment, there is excellent agreement of the peak positions. The peak height agrees well with experiment for the lowest considered momentum transfer (500 MeV/$c$) but tends to be too high for higher momentum transfer (10% at 700 MeV/$c$).

The effects of quantal and thermal fluctuations beyond the BCS quasiparticle mean field on the chemical potential are studied within a model, which consists of $N$ particles distributed amongst $\Omega$ doubly folded equidistant levels interacting via a pairing force with parameter $G$. The results obtained at zero and finite temperatures $T$ within several approaches, which include the fluctuations beyond the BCS theory, are compared with the exact results. The chemical potential, defined as the Lagrangian multiplier to preserve the average number of particles, is compared with the corresponding quantity, which includes the effect from fluctuations of particle and quasiparticle numbers beyond the BCS quasiparticle mean field. The analysis of the results shows that the latter differs significantly from the former as functions of $G$ and $T$. The chemical potential loses its physical meaning in the system with a fixed number of particles or after eliminating quantal fluctuations of particle (quasiparticle) numbers by means of particle number projection. The validity of the criterion for the signature of the transition to Bose-Einstein condensation, which occurs in infinite systems when the chemical potential hits the bottom of the energy spectrum, is reexamined for the finite multilevel model.

Geo-neutrino studies are based on theoretical estimates of geo-neutrino spectra. We propose a method for a direct measurement of the energy distribution of antineutrinos from decays of long-lived radioactive isotopes. We present preliminary results for the geo-neutrinos from ${}^{214}\mathrm{Bi}$ decay, a process that accounts for about one-half of the total geo-neutrino signal. The feeding probability of the lowest state of ${}^{214}\mathrm{Bi}$—the most important for geo-neutrino signal—is found to be $p_0=0.177\pm 0.004\text{ (stat)}{}_{-0.001}^{+0.003}\text{ (sys)}$, under the hypothesis of universal neutrino spectrum shape (UNSS). This value is consistent with the (indirect) estimate of the table of isotopes. We show that achievable larger statistics and reduction of systematics should allow for the testing of possible distortions of the neutrino spectrum from that predicted using the UNSS hypothesis. Implications on the geo-neutrino signal are discussed.

A method is presented for analysis of correlation function of two nonidentical particles with strong and Coulomb interactions, resonance formation, channel coupling, and spin structure. For resonance reactions we derive a formula giving the small distance contribution to the correlation function. The formalism is used to analyze the preliminary Relativistic Heavy Ion Collider data on ${\pi }^{\pm }{\Xi }^{\mp }$ correlation measurements. The ${\Xi }^{*}(1530)$ resonance is successfully described. The $\pi \Xi$ source size is obtained.

The relation between equal-time and light-front wave functions is studied using models for which the four-dimensional solution of the Bethe-Salpeter wave function can be obtained. The popular prescription of defining the longitudinal momentum fraction using the instant-form free kinetic energy and third component of momentum is found to be incorrect except in the nonrelativistic limit. One may obtain light-front wave functions from rest-frame, instant-form wave functions by boosting the latter wave functions to the infinite momentum frame. Despite this difficulty, we prove a relation between certain integrals of the equal-time and light-front wave functions.

We derive a novel model-independent result for the pion susceptibility in QCD via the isovector-pseudoscalar vacuum polarization. In the neighbourhood of the chiral limit, the pion susceptibility can be expressed as a sum of two independent terms. The first expresses the pion-pole contribution. The second is identical to the vacuum chiral susceptibility, which describes the response of QCD's ground state to a fluctuation in the current-quark mass. In this result one finds a straightforward explanation of a mismatch between extant estimates of the pion susceptibility.

All existing positive results on two-neutrino double-$\beta$ decay in different nuclei were analyzed. Using the procedure recommended by the Particle Data Group, weighted average values for half-lives of ${}^{48}\mathrm{Ca}$, ${}^{76}\mathrm{Ge}$, ${}^{82}\mathrm{Se}$, ${}^{96}\mathrm{Zr}$, ${}^{100}\mathrm{Mo}$, ${}^{100}\mathrm{Mo}$-${}^{100}\mathrm{Ru}$ ($0_1^{+}$), ${}^{116}\mathrm{Cd}$, ${}^{130}\mathrm{Te}$, ${}^{150}\mathrm{Nd}$, ${}^{150}\mathrm{Nd}$-${}^{150}\mathrm{Sm}$ ($0_1^{+}$), and ${}^{238}\mathrm{U}$ were obtained. Existing geochemical data were analyzed, and recommended values for half-lives of ${}^{128}\mathrm{Te}$, ${}^{130}\mathrm{Te}$, and ${}^{130}\mathrm{Ba}$ are proposed. Given the measured half-life values, nuclear matrix elements were calculated. I recommend the use of these results as the most currently reliable values for the half-lives and nuclear matrix elements.

We present a Brueckner theory analysis of proton-scattering data from Sn isotopes at 295 MeV. A soft-core Urbana $v_{14}$ internucleon potential has been used to calculate reaction matrices that are folded with point-nucleon (both proton and neutron) densities obtained in the relativistic mean field (RMF) framework to calculate the optical potential. We get reasonably satisfactory agreement with the differential cross-section and analyzing-power data using only three scaling parameters for all isotopes. It is observed that the calculated neutron skin increases smoothly as the neutron number increases, in conformity with earlier findings.

A resonance-like structure of internal conversion coefficients (ICCs) at low $\gamma$-ray energy ($\lesssim$100 keV) is studied. Our calculations revealed new, previously unknown resonance minima in the energy dependence of ICCs for the $\mathit{ns}$ shells at $E2$–$E5$ transitions. The resonances are the most defined for ICCs in light and medium elements with $Z\lesssim$ 50. It is shown that ICCs may have up to four resonances for outer shells while it has been assumed so far that only one resonance exists. Well-pronounced resonances in ICCs at $E1$ transition were discovered for the $\mathit{ns}$ shells with $n⩾2$ as well as for the $\mathit{np}$ shells with $n⩾3$ and the $\mathit{nd}$ shells with $n⩾4$ of all elements up to superheavy ones. Simple expressions for approximate values of the $E1$ resonance energy were obtained which are of importance for determination of the resonance energy range where the interpolation of ICCs taken from tables or databases may give significant errors. The occurrence of resonances in ICCs is explained by vanishing conversion matrix elements under changes of sign. The peculiarities of the behavior of the matrix elements and electron wave functions at the resonance energy are considered. Available experimental ICCs for electric transitions with energies near the expected position of resonances satisfactory agree with our calculations.