A new isomer in ${}^{116}\mathrm{Ag}$ with a half-life of 20(1) s has been discovered through the use of conversion electron, β, and γ spectroscopy of on-line mass-separated radioactivities at the Holifield Radioactive Ion Beam Facility at ORNL. The observed electron peaks at 22.5, 44.42, and 47.33 keV were interpreted as the $K,L$, and M conversion electron lines resulting from a 47.9-keV $E3$ transition associated with the decay of a second isomeric level in ${}^{116}\mathrm{Ag}$. A new level structure of ${}^{116}\mathrm{Ag}$ is proposed, with the levels identified as the $0^{-}$ ground-state and isomers at 47.9 and 128.8 keV having spin/parities of $3^{+}$ and $6^{-}$ respectively.

A formalism is developed and predictions are made for selected polarization observables in one-nucleon knockout reactions within the transfer-to-the-continuum direct reaction model. The effects of nucleon-target spin-orbit distortions are also included and their importance is quantified. The calculated knockout reaction analyzing powers reach an appreciable fraction of their maximum allowed values. They are also found to be quite sensitive to the different approximation schemes used for the transfer probability amplitude within the transfer-to-the-continuum model. In contrast, they are shown to be insensitive to details of the two-body interactions assumed, including the nucleon-target spin-orbit interaction. The angular distributions of γ-rays, arising from the decay of heavy reaction residues produced in excited final states, are shown to be strongly anisotropic.

We present results for two-particle transverse momentum correlations, $\langle \Delta p_{t,i}\Delta p_{t,j}\rangle$, as a function of event centrality for Au+Au collisions at $\sqrt{s_{\mathit{NN}}}=20$, 62, 130, and 200 GeV at the BNL Relativistic Heavy Ion Collider. We observe correlations decreasing with centrality that are similar at all four incident energies. The correlations multiplied by the multiplicity density increase with incident energy, and the centrality dependence may show evidence of processes such as thermalization, jet production, or the saturation of transverse flow. The square root of the correlations divided by the event-wise average transverse momentum per event shows little or no beam energy dependence and generally agrees with previous measurements made at the CERN Super Proton Synchrotron.

We argue that recent NA49 results on multiparticle distributions and fluctuations, as a function of the number of participant nucleons, suggest that percolation plays an important role in particle production at high densities.

An extended group-theoretical approach to magnetic moments of the octet baryons is proposed with the aim of extracting the strange magnetic moment of the nucleon. Special attention is given to flavor SU(3) breaking. In this approach, isoscalar and isovector magnetic moments are treated separately in view of their different behavior under SU(3) breaking. We conclude that the anomalous magnetic moment associated with the flavor singlet current is small. Together with the small isoscalar anomalous magnetic moment of the nucleon, this implies suppression of the strange magnetic moment of the proton which is found to be small and positive, ${\mu }^{(s)}=(0.16\pm 0.03){\mu }_N$ in units of the nuclear magneton.

Rotational and deformation dependence of isovector and isoscalar pairing correlations at finite temperature are studied in an exactly solvable cranked deformed shell model Hamiltonian. It is shown that isovector pairing correlations, as expected, decrease with increasing deformation and the isoscalar pairing correlations remain constant at temperature, $T=0$. However, it is observed that at finite temperature both isovector and isoscalar pairing correlations are enhanced with increasing deformation. It is also demonstrated that the pair correlations, which are quenched at $T=0$ and high rotational frequency reappear at finite temperature. The changes in the individual multipole pairing fields as a function of rotation and deformation are analyzed in detail.

The nuclear incompressibility κ is investigated in asymmetric systems in a mean field model. The calculations are done at zero and finite temperatures and include surface, Coulomb and symmetry energy terms for several equations of state. Also considered is the behavior of the incompressibility at constant entropy ${\kappa }_Q$ which is shown to have a very different behavior than the isothermal κ. Namely, ${\kappa }_Q$ decreases with increasing entropy while the isothermal κ increases with increasing T. A duality is found between the adiabatic ${\kappa }_Q$ and the $T=0$ isothermal κ. Analytic and also simple approximate expressions for κ are given which illustrate the role of various terms that enter into κ. Namely, properties of the interaction used, the value of the effective mass, and its density dependence all play an important role.

Analyzing power data are reported for exclusive proton-induced proton knockout from the $1s_{1/2}$ states of 10 target nuclei ranging from ${}^2\mathrm{H}$ to ${}^{19}\mathrm{F}$ for an incident energy of 392 MeV. Compared to free proton-proton scattering, the data are significantly suppressed, the amount of suppression increasing monotonically as a function of increasing separation energies for the knocked-out protons. It is also possible to consider that this suppression increases monotonically as a function of the increasing effective mean density for most of the target nuclei, but data for ${}^3\mathrm{He}$ and ${}^4\mathrm{He}$ targets clearly deviate from such systematic change. The data are compared to model predictions based on the nonrelativistic and relativistic distorted-wave impulse approximation. Both relativistic plane wave model and a nonrelativistic distorted-wave model incorporating a relativistic correction associated with an effective nucleon mass predict a significant suppression of the analyzing power, but the magnitude of the suppression is not sufficient to explain the experimental data. However, a relativistic distorted wave model predicts values that are closer to the data, but the result is inconclusive in this work since recoil corrections are neglected.

Single particle spectra as well as elliptic flow in Cu+Cu collisions at $\sqrt{s_{\mathit{NN}}}=200$ GeV are investigated within a hadronic cascade model and an ideal hydrodynamic model. Pseudorapidity distribution and transverse momentum spectra for charged hadrons are surprisingly comparable between these two models. However, a large deviation is predicted for the elliptic flow. The forthcoming experimental data will clarify the transport and thermalization aspects of matter produced in Cu+Cu collisions.

Excited states in ${}^{113}\mathrm{In}$ were populated via the reactions ${}^{100}\mathrm{Mo}$(${}^{18}\mathrm{O}$,$p4n$)${}^{113}\mathrm{In}$ and ${}^{110}\mathrm{Pd}$(${}^7\mathrm{Li}$,$4n$)${}^{113}\mathrm{In}$. The two known $\Delta J=2$ intruder bands, based on the $\pi g_{7/2}\otimes d_{5/2}$ and $\pi h_{11/2}$ orbitals, have been extended by 8$\hslash$ to spins $(49/2^{+})\hslash$ and $(55/2^{-})\hslash$, respectively. The previous finding of three sequences of $\Delta J=1$ γ-ray transitions has been confirmed. A self-consistent cranked shell-model calculation gives a good description of the contrasting alignment patterns of the two $\Delta J=2$ intruder bands. The intruder bands, the known sequences of $M1$ transitions, and spherical levels together represent a coexistence of three different excitation modes in this nucleus.

The paper presents differences in the results of the optical-model analyses of nuclear elastic scattering data when the true ${\chi }^2$ and its approximation, i.e., the Δ test functions, are used in an automatic search for the best model parameters.

Angular distribution for ${}^7\mathrm{Be}+{}^7\mathrm{Li}$ elastic scattering has been measured using a ${}^7\mathrm{Be}$ radioactive beam at the Nuclear Science Center, New Delhi, at $E_{c.m.}=9.87$ and 8.87 MeV. A compact and highly efficient detector system in kinematic coincidence mode and an in-vacuum target transfer system have been developed to minimize contributions from unwanted channels. The angular ranges covered were ${\theta }_{c.m.}={42}^{°}–{66}^{°}$ and ${\theta }_{c.m.}={114}^{°}–{138}^{°}$. At the backward angles at both energies, the experimental angular distribution shows higher cross sections than the theoretical predictions for the direct elastic channel alone. The experimental data could be fitted with an isospin-dependent complex potential that is analogous to the Lane potential. A coupled-channel calculation with ground-state reorientation could also fit the data.

Data on single- and double-charged-pion electroproduction off protons are successfully described in the second and third nucleon resonance regions with common $N^{*}$ photocouplings. The analysis was carried out with separate isobar models for both reactions. From the combined analysis of two exclusive channels, the ${\gamma }^{*}p\to N^{*+}$ helicity amplitudes are obtained for the resonances $P_{11}(1440),D_{13}(1520),S_{31}(1620),S_{11}(1650),F_{15}(1680),D_{33}(1700),D_{13}(1700)$, and $P_{13}(1720)$ at $Q^2=0.65(\mathrm{GeV}/c){}^2$.

We consider the impact of two recent ${\pi }^{-}p\to \eta n$ measurements on the $\eta N$ scattering length and $\eta N$ branching fractions for the $N(1535)$ and $N(1520)$ resonances within a coupled-channel analysis of $\pi N$ elastic scattering and $\eta N$ production data. The sensitivity of these results to model input is also explored.

The correlation between the thickness of the neutron skin in ${}^{208}\mathrm{Pb}$ and the degree of isospin diffusion in heavy-ion collisions is examined. The same equation of state is used to compute the degree of isospin diffusion in an isospin-depedent transport model and the neutron skin thickness in the Hartree-Fock approximation. We find that skin thicknesses less than 0.15 fm are excluded by the isospin diffusion data.

The g factor of the $4_1^{+}$ state in ${}^{68}\mathrm{Zn}$ was remeasured with improved energy resolution of the detectors used. The value obtained is consistent with the previous result of a negative g factor, thus confirming the dominant $0g_{9/2}$ neutron nature of the $4_1^{+}$ state. In addition, the accuracy of the g factors of the $2_1^{+},2_2^{+}$, and $3_1^{-}$ states has been improved and their lifetimes were well reproduced. New large-scale shell-model calculations based on a ${}^{56}\mathrm{Ni}$ core and a $0f_{5/2}1p0g_{9/2}$ model space yield a theoretical value, $g(4_1^{+})=+0.008$. Although the calculated value is small, it cannot fully explain the experimental value, $g(4_1^{+})=-0.37(17)$. The magnitude of the deduced $B(E2)$ of the $4_1^{+}$ and $2_1^{+}$ transitions is, however, rather well described. These results demonstrate again the importance of g factor measurements for nuclear structure determinations because of their specific sensitivity to detailed proton and neutron components in the nuclear wave functions.

High-spin states in ${}^{190}\mathrm{Tl}$ have been studied experimentally by using the ${}^{160}\mathrm{Gd}$(${}^{35}\mathrm{Cl}$,5n) fusion-evaporation reaction at beam energies of 167 and 175 MeV. A rotational band built on the $\pi h_{9/2}\otimes \nu i_{13/2}$ configuration with oblate deformation has been established for ${}^{190}\mathrm{Tl}$. Spin values are assigned by adopting the results from $\alpha -\gamma$ decay work for ${}^{194}\mathrm{Bi}$ found in the literature. With the configuration and spin-parity assignments, the low-spin signature inversion has been revealed for the $\pi h_{9/2}\otimes \nu i_{13/2}$ oblate band in ${}^{190}\mathrm{Tl}$. It is the first experimental observation of low-spin signature inversion for a band associated with the oblate $\pi h_{9/2}\otimes \nu i_{13/2}$ configuration. The low-spin signature inversion for the oblate $\pi h_{9/2}\otimes \nu i_{13/2}$ band can be interpreted by the two-quasiparticle-plus-rotor model including a J-dependent $p-n$ residual interaction.

By applying the particle-number projection to the finite-temperature Bardeen-Cooper-Schrieffer (BCS) theory, the S-shaped heat capacity, which has recently been claimed to be a fingerprint of the superfluid-to-normal phase transition in nuclei, is reexamined. It is found that the particle-number (or number-parity) projection gives S shapes in the heat capacity of nuclei that look qualitatively similar to the observed ones. These S shapes are accounted for as effects of the particle-number conservation on the quasiparticle excitations and occur even when we keep the superfluidity at all temperatures by assuming a constant gap in the BCS theory. The present study illustrates significance of the conservation laws in studying phase transitions of finite systems.

The measured transverse momentum spectra and HBT correlations of bulk (i.e., low $p_T$) matter can be well explained by assuming that the soft sector of particles produced in ultrarelativistic heavy-ion collisions is (approximately) thermalized and undergoes collective accelerated expansion in both longitudinal and transverse direction. However, this implies that bulk matter will have a nonvanishing flow component transverse to the trajectory of a high $p_T$ partonic jets. In general, this will increase the energy loss experienced by the jet parton and modify the shape of the jet cone. In this paper, we present a systematic study of the magnitude of the additional energy loss induced by flow under realistic assumptions for the medium evolution. We argue that a perturbative QGP description may be sufficient for the measured $R_{\mathit{AA}}$ if flow during the medium evolution is taken into account properly.

Recently, we have derived the leading and subleading isospin-breaking three-nucleon forces using the method of unitary transformation. In the present work we extend this analysis and consider the corresponding two-nucleon forces using the same approach. Certain contributions to the isospin-violating one- and two-pion-exchange potential have already been discussed by various groups within the effective field theory framework. Our findings agree with the previously obtained results. In addition, we present the expressions for the subleading charge-symmetry-breaking two-pion exchange potential which were not considered before. These corrections turn out to be numerically important. Together with the three-nucleon force results presented in our previous work, the results of the present study specify completely isospin-violating nuclear forces up to the order $q^5/{\Lambda }^5$, where q (Λ) denotes the soft (hard) scale.