Time reversal invariance-violating (TRIV) effects in low-energy elastic neutron-deuteron scattering are calculated using meson exchange and EFT-type TRIV potentials in a distorted-wave Born approximation with realistic hadronic strong interaction wave functions, obtained by solving the three-body Faddeev equations in configuration space. The relation between TRIV and parity-violating observables is discussed.

A complete high precision set of deuteron analyzing powers for elastic deuteron-proton ($\mathit{dp}$) scattering at 250 MeV/nucleon (MeV/N) has been measured. The new data are presented together with data from previous measurements at 70, 100, 135 and 200 MeV/N. They are compared with the results of three-nucleon (3N) Faddeev calculations based on modern nucleon-nucleon (NN) potentials alone or combined with two models of three nucleon forces (3NFs): the Tucson-Melbourne 99 (TM99) and Urbana IX. At 250 MeV/N large discrepancies between pure NN models and data, which are not resolved by including 3NFs, were found at c.m. backward angles of ${\theta }_{\mathrm{c}.\mathrm{m}.}\gtrsim {120}^{°}$ for almost all the deuteron analyzing powers. These discrepancies are quite similar to those found for the cross section at the same energy. We found small relativistic effects that cannot resolve the discrepancies with the data indicating that other, short-ranged 3NFs are required to obtain a proper description of the data.

Kaons and protons carry large parts of two conserved quantities: strangeness and baryon number. It is argued that their correlation and thus also fluctuations are sensitive to conditions prevailing at the anticipated parton-hadron phase boundary. Fluctuations of the $({\mathrm{K}}^{+}+{\mathrm{K}}^{-})/(\mathrm{p}+\overline{\mathrm{p}})$ and ${\mathrm{K}}^{+}/\mathrm{p}$ ratios have been measured for the first time by NA49 in central $\mathrm{Pb}+\mathrm{Pb}$ collisions at five CERN Super Proton Synchrotron energies between $\sqrt{s_{{}_{\mathrm{NN}}}}=6.3$ and $\sqrt{s_{{}_{\mathrm{NN}}}}=17.3$ GeV. Both ratios exhibit a change of sign in ${\sigma }_{\mathrm{dyn}}$, a measure of nonstatistical fluctuations, around $\sqrt{s_{{}_{\mathrm{NN}}}}=8$ GeV. Below this energy, ${\sigma }_{\mathrm{dyn}}$ is positive, indicating higher fluctuation compared to a mixed event background sample, while for higher energies, ${\sigma }_{\mathrm{dyn}}$ is negative, indicating correlated emission of kaons and protons. The results are compared to hadronic transport model calculations which fail to reproduce the energy dependence.

The decay of a new, $53/2^{+}$, isomer at 8281 keV in ${}^{203}\mathrm{Hg}$ has been studied by $\gamma$ coincidence spectroscopy. A half-life of 146(30) ns was measured. In addition, another isomeric, $39/2^{+}$, level with a half-life of $7.8(1.5)$ ns was observed. Some elements of the Rydstroem shell-model interaction have been adjusted to reproduce level energies in nuclei with two to four holes in the ${}^{208}\mathrm{Pb}$ core. With this interaction, the new states in the five-hole nucleus ${}^{203}\mathrm{Hg}$ are reproduced with an rms error of 105 keV.

The $E1$ strength function for 15 stable and unstable Sn even-even isotopes from $A=100$ to $A=176$ are calculated using a self-consistent microscopic theory which, in addition to the standard (quasiparticle) random-phase approximation [(Q)RPA] approach, takes into account phonon coupling and the single-particle continuum (by means of the discretization procedure) with a cutoff of 100 MeV. Our analysis shows two distinct regions for which the integral characteristics of both the giant and pygmy resonances behave rather differently. For neutron-rich nuclei, starting from ${}^{132}\mathrm{Sn}$, we obtain a giant $E1$ resonance which significantly deviates from the widely used systematics extrapolated from experimental data in the $\beta$-stability valley. We show that the inclusion of phonon coupling is necessary for a proper description of the low-energy pygmy resonances and the corresponding transition densities for $A<132$ nuclei, while in the $A>132$ region the influence of phonon coupling is significantly smaller. The radiative neutron capture cross sections leading to the stable ${}^{124}\mathrm{Sn}$ and unstable ${}^{132}\mathrm{Sn}$ and ${}^{150}\mathrm{Sn}$ nuclei are calculated with both the (Q)RPA and the beyond-(Q)RPA strength functions and shown to be sensitive to both the predicted low-lying strength and the phonon-coupling contribution. The comparison with the widely used phenomenological generalized Lorentzian approach shows considerable differences both for the strength function and the radiative neutron capture cross section. In particular, for the neutron-rich ${}^{150}\mathrm{Sn}$, the reaction cross section is found to be increased by a factor greater than 20. We conclude that the present approach may provide a complete and coherent description of the $\gamma$-ray-strength function for astrophysics applications. In particular, such calculations are highly recommended for a reliable estimate of the electromagnetic properties of exotic nuclei.

Fluctuations in the initial geometry of a nucleus-nucleus collision have been recently shown to result in a new type of directed flow ($v_1$) that, unlike the usual directed flow, is also present at midrapidity. We compute this new $v_1$ versus transverse momentum and centrality for Au-Au collisions at RHIC using the hydrodynamic code NeXSPheRIO. We find that the event plane of $v_1$ is correlated with the angle of the initial dipole of the distribution, as predicted, though with a large dispersion. It is uncorrelated with the reaction plane. Our results are in excellent agreement with results inferred from STAR correlation data.

The recently discovered $Z(4430)$ mesonic resonance is believed to be a strong tetraquark candidate. The photoproduction in the channel $\gamma p\to Z^{+}(4430)n\to {\psi }^{\text{'}}{\pi }^{+}n$ has been proposed as the most effective way to confirm the $Z(4430)$ presence and to measure its quantum numbers. In this work we present a model for high-energy and forward-angle $Z(4430)$ photoproduction in a effective Lagrangian approach. This model is based on the use of Regge trajectories exchange, thus a Regge propagator replaces the usual Feynman propagator. The differential and total cross sections and the asymmetries have been calculated for the $J^P$ quantum numbers $1^{-}$, $1^{+}$, $0^{-}$, and $2^{-}$ in the hypotheses where $Z(4430)$ has isospin $I=1$.

With the use of pionless effective field theory including dibaryon fields, we study the $\gamma d\to \mathrm{n⃗}p$ reaction for the laboratory photon energy $E_{\gamma }{}^{\mathrm{lab}}$ ranging from threshold to 30 MeV. Our main goal is to calculate the neutron polarization $P_{y^{\prime }}$ defined as $P_{y^{\prime }}=({\sigma }_{+}-{\sigma }_{-})/({\sigma }_{+}+{\sigma }_{-})$, where ${\sigma }_{+}$ and ${\sigma }_{-}$ are the differential cross sections for the spin-up and spin-down neutrons, respectively, along the axis perpendicular to the reaction plane. We also calculate the total cross section as well as the differential cross section $\sigma (\theta )$, where $\theta$ is the colatitude angle. Although the results for the total and differential cross sections are found to agree reasonably well with the data, the results for $P_{y^{\prime }}$ show significant discrepancy with the experiment. We comment on this discrepancy.

A study is carried out on the role of the aligned neutron-proton pair with angular momentum $J=9$ and isospin $T=0$ in the low-energy spectroscopy of the $N=Z$ nuclei ${}^{96}\mathrm{Cd}$, ${}^{94}\mathrm{Ag}$, and ${}^{92}\mathrm{Pd}$. Shell-model wave functions resulting from realistic interactions are analyzed in terms of a variety of two-nucleon pairs corresponding to different choices of their coupled angular momentum $J$ and isospin $T$. The analysis is performed exactly for four holes (${}^{96}\mathrm{Cd}$) and carried further for six and eight holes (${}^{94}\mathrm{Ag}$ and ${}^{92}\mathrm{Pd}$) by means of a mapping to an appropriate version of the interacting boson model. The study allows the identification of the strengths and deficiencies of the aligned-pair approximation.

We compute cross sections for incoherent diffractive $J/\Psi$ production in lepton-nucleus deep-inelastic scattering (DIS). The cross section is proportional to $A$ in the dilute limit and to $A^{1/3}$ in the black disk limit, with a large nuclear suppression due to saturation effects. The $t$ dependence of the cross section, if it can be measured accurately enough, is sensitive to the impact parameter profile of the gluons in the nucleus and their fluctuations, a quantity that determines the initial conditions of a relativistic heavy-ion collision. The nuclear suppression in incoherent diffraction shows how the transverse spatial distribution of the gluons in the nucleus gradually becomes smoother at high energy. Since the values of the momentum transfer $\left|t\right|$ involved are relatively large, this process should be easier to measure in future nuclear DIS experiments than coherent diffraction.

Excited states in the neutron-deficient nucleus ${}^{167}\mathrm{Ta}$ were studied through the ${}^{120}\mathrm{Sn}$(${}^{51}\mathrm{V}$,$4n$) reaction. Twelve rotational bands have been observed and the relative excitation energy of each sequence is now known owing to the multiple interband connections. Several quasineutron alignments were observed that aided in the quasiparticle assignments of these bands. The resulting interpretation is in line with observations in neighboring nuclei. Trends in the wobbling phonon energy seen in ${}^{161,163,165,167}\mathrm{Lu}$ and ${}^{167}\mathrm{Ta}$ are also discussed and particle-rotor model calculations (assuming constant moments of inertia) are found to be inconsistent with the experimental data.

Multiple Coulomb-excitation experiments for ${}^{156}\mathrm{Gd}$ were made with a 118 MeV ${}^{32}\mathrm{S}$ beam and a 225 MeV ${}^{58}\mathrm{Ni}$ beam. The ground-state band, the $\beta$ band ($K=0^{+}$), another $K=0^{+}$ band, and the $\gamma$ band ($K=2^{+}$) were observed up to the ${18}^{+}$, ${14}^{+}$, $8^{+}$, and ${12}^{+}$ states, respectively, while the octupole band ($K=1^{-}$) was observed up to the ${15}^{-}$ state, through the analysis of particle-$\gamma$-$\gamma$ data. Compared with the results of the in-beam $\gamma$-ray spectroscopy previously obtained, the present result suggests that a band crossing occurs in the $\gamma$ band. As for the $\beta$ band, the excitation energy of the ${12}^{+}$ state was revised and the ${14}^{+}$ state was newly observed in the present experiment. The intrinsic matrix elements entering the generalized intensity relations were obtained so as to reproduce the spin dependence of the $E2$ matrix elements extracted from the experimental results of particle-$\gamma$ angular correlation for the transitions within each band and between each band and the ground-state band by the least-squares search code gosia. The change of characters in the $\beta$ and $\gamma$ bands is discussed as a possible cause for the variation of the $E2$ matrix elements in the higher-spin region. The intrinsic matrix elements were also obtained for the $E1$ and $E3$ transitions from the ground-state band to the octupole band with $K=1^{-}$ through analysis by gosia.

Detailed quantitative predictions are obtained for phonon and multiphonon excitations in well-deformed rotor nuclei within the geometric framework, by exact numerical diagonalization of the Bohr Hamiltonian in an $\mathrm{SO}(5)$ basis. Dynamical $\gamma$ deformation is found to significantly influence the predictions through its coupling to the rotational motion. Basic signatures for the onset of rigid triaxial deformation are also obtained.

High-spin excited states in the very neutron-rich nucleus ${}^{114}\mathrm{Rh}$ have been studied by examining the prompt $\gamma$ rays emitted in the spontaneous fission of ${}^{252}\mathrm{Cf}$ with the Gammasphere detector array. A high-spin level scheme of ${}^{114}\mathrm{Rh}$ has been established for the first time with 13 new levels. The level scheme is proposed to be built on a $7^{-}$ state. The existence of a relatively large signature splitting and an yrare band show features which may indicate triaxial deformation. The phenomenon of signature inversion has been observed in ${}^{114}\mathrm{Rh}$ at $I=12\hspace{0.5em}\hslash$. The observed signature inversion of ${}^{114}\mathrm{Rh}$ is interpreted successfully in terms of the triaxial projected shell model. Theoretical calculations suggest that the negative-parity, yrast band of ${}^{114}\mathrm{Rh}$ has the two-quasi-particle configuration of $\pi g_{9/2}\otimes \nu h_{11/2}$, consistent with the systematics of odd-odd Rh isotopes. The signature inversion at spin $12\hspace{0.5em}\hslash$ may be attributed to the change of rotational mode, from quasi-particle aligned rotation at low spins to collective rotation at high spins.

The energies of 2-quasiparticle (2-qp) states in heavy shell-stabilized nuclei provide information on the single-particle states that are responsible for the stability of superheavy nuclei. We have calculated the energies of 2-qp states in ${}^{256}\mathrm{Rf}$, which suggest that a long-lived, low-energy 8${}^{-}$ isomer should exist. A search was conducted for this isomer through a calorimetric conversion electron signal, sandwiched in time between implantation of a ${}^{256}\mathrm{Rf}$ nucleus and its fission decay, all within the same pixel of a double-sided Si strip detector. A 17(5)-$\mu$s isomer was identified. However, its low population, $~$5(2)$\%$ that of the ground state instead of the expected $~$30$\%$, suggests that it is more likely a 4-qp isomer. Possible reasons for the absence of an electromagnetic signature of a 2-qp isomer decay are discussed. These include the favored possibility that the isomer decays by fission, with a half-life indistinguishably close to that of the ground state. Another possibility, that there is no 2-qp isomer at all, would imply an abrupt termination of axially symmetric deformed shapes at $Z=104$, which describes nuclei with $Z=92$–103 very well.

The change in the structure of the collective levels with spin angular momentum in atomic nuclei is often expressed in terms of the classical concepts of the kinematic and the dynamic moments of inertia varying with spin. For the well deformed even-even nuclei the kinematic moment of inertia increases with spin up to 10%–20%, at say $I^{\mathrm{\pi }}$ $=$ 12${}^{+}$. However, for the shape transitional nuclei, or almost spherical nuclei, it increases with spin much faster. The pitfalls of using the rotor model form of kinematic moment of inertia in such cases are pointed out here. Alternative methods of extracting the nuclear structure information are explored. The important role of the ground state deformation is illustrated. The use of the power index formula for evaluating the effective moment of inertia, free from the assumption of the rotor model, is described.

One-neutron knockout data for ${}^{18-22}\mathrm{N}$ are analyzed in the eikonal approximation of the Glauber model. The role of the $s$-$d$ shell and the crossing of the $N=14$ neutron subshell are discussed. Of particular interest is the nucleus ${}^{22}\mathrm{N}$, where the knockout data provide a sensitive experimental test for a possible halo structure of its ground state. The observation of a narrow momentum distribution of the ${}^{21}\mathrm{N}$ fragments, together with an essential 1$s_{1/2}$ contribution needed to describe the observed longitudinal-momentum distribution, allow the firm conclusion that the ground state of ${}^{22}\mathrm{N}$ is a well-developed nuclear halo. The results also show that the $N=14$ subshell in ${}^{22}\mathrm{N}$ is somewhat reduced as compared to that of ${}^{23}\mathrm{O}$.

New data for the ${}^6\mathrm{He}+{}^9\mathrm{Be}$ reaction at $E_{\mathrm{lab}}=16.2$ and 21.3 MeV have been taken and analyzed. The effect of the collective couplings to the excited states of the target has been studied by means of coupled-channels calculations, using a double-folding potential for the bare interaction between the colliding nuclei, supplemented with a phenomenological imaginary part of Woods-Saxon type. In addition, three- and four-body continuum-discretized coupled-channels calculations have been performed to investigate the effect of the projectile breakup on the elastic scattering. Both effects, the coupling to target and projectile excited states, are found to affect significantly the elastic scattering. The trivial local polarization potential extracted from the continuum-discretized coupled-channels calculations indicates that continuum couplings produce a repulsive real part and a long-range imaginary part in the projectile-target interaction.

We study nuclear dynamics at the the energy of vanishing flow for neutron-rich systems. In particular, we study the collision rate, density, and temperature reached in a heavy-ion reaction with neutron-rich systems and the mass dependence of these quantities. Our results indicate nearly mass-independent nature for the density, whereas a significant mass dependence exists for the temperature of neutron-rich systems.

Neutron elastic-scattering angular distributions were measured at beam energies of 11.9 and 16.9 MeV on ${}^{40,48}\mathrm{Ca}$ targets. These data plus other elastic-scattering measurements, total and reaction cross-sections measurements, $(e,e^{\prime }p)$ data, and single-particle energies for magic and doubly magic nuclei have been analyzed in the dispersive optical-model (DOM), generating nucleon self-energies (optical-model potentials) that can be related, via the many-body Dyson equation, to spectroscopic factors and occupation probabilities. It is found that, for stable nuclei with $N⩾Z$, the imaginary surface potential for protons exhibits a strong dependence on the neutron-proton asymmetry. This result leads to a more modest dependence of the spectroscopic factors on asymmetry. The measured data and the DOM analysis of all considered nuclei clearly demonstrate that the neutron imaginary surface potential displays very little dependence on the neutron-proton asymmetry for nuclei near stability ($N⩾Z$).