The deuteron-emission channel in the $\beta$ decay of the halo nucleus ${}^{11}\mathrm{Li}$ was measured at the Isotope Separator and Accelerator facility at TRIUMF by implanting postaccelerated ${}^{11}\mathrm{Li}$ ions into a segmented silicon detector. The events of interest were identified by correlating the decays of ${}^{11}\mathrm{Li}$ with those of the daughter nuclei. This method allowed the energy spectrum of the emitted deuterons to be extracted, free from contributions from other channels, and a precise value for the branching ratio $B_d=1.30(13)\times {10}^{-4}$ to be deduced for $E_{\mathrm{c}.\mathrm{m}.}>200\mathrm{keV}$. The results provide the first unambiguous experimental evidence that the decay takes place essentially in the halo of ${}^{11}\mathrm{Li}$ and that it proceeds mainly to the ${}^9\mathrm{Li}+d$ continuum, opening up a new means to study the halo wave function of ${}^{11}\mathrm{Li}$.

The ground state hyperfine splitting of ${}^7\mathrm{Be}^{+}$ has been measured by laser-microwave double-resonance spectroscopy in the online rf trap of RIKEN’s slow RI-beam facility. Be ions produced by projectile fragmentation of ${}^{13}\mathrm{C}$ at $\approx 1\mathrm{GeV}$ were thermalized in a rf ion guide gas cell and subsequently laser cooled in the ion trap to $\approx 1\mu \mathrm{eV}$. This ${10}^{15}$-fold reduction of the kinetic energy allows precision spectroscopy of these ions. A magnetic hfs constant of $A=-742.77228(43)\mathrm{MHz}$ was measured for ${}^7\mathrm{Be}^{+}$, from which a nuclear magnetic moment of ${\mu }_I=-1.39928(2){\mu }_N$ was deduced.

In this Letter, we report a new mass for ${}^{11}\mathrm{Li}$ using the trapping experiment TITAN at TRIUMF’s ISAC facility. This is by far the shortest-lived nuclide, $t_{1/2}=8.8\mathrm{ms}$, for which a mass measurement has ever been performed with a Penning trap. Combined with our mass measurements of ${}^{8,9}\mathrm{Li}$ we derive a new two-neutron separation energy of 369.15(65) keV: a factor of 7 more precise than the best previous value. This new value is a critical ingredient for the determination of the halo charge radius from isotope-shift measurements. We also report results from state-of-the-art atomic-physics calculations using the new mass and extract a new charge radius for ${}^{11}\mathrm{Li}$. This result is a remarkable confluence of nuclear and atomic physics.

We present experimental results of the first high-precision test of quark-hadron duality in the spin-structure function $g_1$ of the neutron and ${}^3\mathrm{He}$ using a polarized ${}^3\mathrm{He}$ target in the four-momentum-transfer-squared range from 0.7 to $4.0(\mathrm{GeV}/c{)}^2$. Global duality is observed for the spin-structure function $g_1$ down to at least $Q^2=1.8(\mathrm{GeV}/c{)}^2$ in both targets. We have also formed the photon-nucleon asymmetry $A_1$ in the resonance region for ${}^3\mathrm{He}$ and found no strong $Q^2$ dependence above $2.2(\mathrm{GeV}/c{)}^2$.

We report on experimental evidence for collective oblate rotation becoming favored at high spins in a rigid, well-deformed, axially symmetric nucleus. Excited states established up to spin $20\hslash$ in ${}^{180}\mathrm{Hf}$ are consistent with predictions that nucleon alignments would favor oblate over prolate shapes at high spins in neutron-rich Hf isotopes. The results highlight the influence of valence orbitals on the interplay between nucleon alignments and nuclear shapes and provide a rare example of independent particle dynamics in competing potential wells.

Recent experimental data at GSI on the rates of the number of daughter ions, produced by the nuclear $K$-shell electron capture (EC) decays of the H-like ions ${}^{140}\mathrm{Pr}^{58+}$ and ${}^{142}\mathrm{Pm}^{60+}$, suggest that they are modulated in time with periods $T_{\mathrm{EC}}\simeq 7\sec$ and amplitudes $a_{\mathrm{EC}}\simeq 0.20$. Since it is known that these ions are unstable also under the nuclear positron (${\beta }^{+}$) decays, we study a possible time dependence of the nuclear ${\beta }^{+}$-decay rate of the H-like ${}^{140}\mathrm{Pr}^{58+}$ ion. We show that the time dependence of the ${\beta }^{+}$-decay rate of the H-like ${}^{140}\mathrm{Pr}^{58+}$ ion as well as any H-like heavy ions cannot be observed.

Neutral pion transverse momentum ($p_T$) spectra at midrapidity ($|y|\lesssim 0.35$) were measured in $\mathrm{Cu}+\mathrm{Cu}$ collisions at $\sqrt{s_{NN}}=22.4$, 62.4, and 200 GeV. Relative to ${\pi }^0$ yields in $p+p$ collisions scaled by the number of inelastic nucleon-nucleon collisions ($N_{\mathrm{coll}}$) the ${\pi }^0$ yields for $p_T\gtrsim 2\mathrm{GeV}/c$ in central $\mathrm{Cu}+\mathrm{Cu}$ collisions are suppressed at 62.4 and 200 GeV whereas an enhancement is observed at 22.4 GeV. A comparison with a jet-quenching model suggests that final state parton energy loss dominates in central $\mathrm{Cu}+\mathrm{Cu}$ collisions at 62.4 and 200 GeV, while the enhancement at 22.4 GeV is consistent with nuclear modifications in the initial state alone.

The magnetic scenario for strongly coupled quark-gluon plasma (sQGP) emphasizes the role of monopoles near or above the deconfinement temperature, and specifically predicts that they help reduce its viscosity by the “magnetic bottle” effect. Here we present results for monopole-(anti)monopole correlation functions from our classical molecular dynamics simulations, which are in good agreement with the lattice results. By analysis of the correlation functions, we show that the magnetic Coulomb coupling runs in the direction opposite to the electric one. However, as $T$ decreases to $T_c$, the magnetic coupling never gets too weak, with the plasma parameter always large enough ($\Gamma >1$). This nicely agrees with empirical evidence from the BNL Relativistic Heavy Ion Collider experiments, implying that magnetic objects should also form a good liquid with low viscosity.

The ${}^{18}\mathrm{O}(p,\alpha ){}^{15}\mathrm{N}$ reaction is of primary importance in several astrophysical scenarios, including fluorine nucleosynthesis inside asymptotic giant branch stars as well as oxygen and nitrogen isotopic ratios in meteorite grains. Thus the indirect measurement of the low energy region of the ${}^{18}\mathrm{O}(p,\alpha ){}^{15}\mathrm{N}$ reaction has been performed to reduce the nuclear uncertainty on theoretical predictions. In particular the strength of the 20 and 90 keV resonances has been deduced and the change in the reaction rate evaluated.

The $\beta$ decay of ${}^{33}\mathrm{Mg}$ ($N=21$) presented in this Letter reveals intruder configurations in both the parent and the daughter nucleus. The lowest excited states in the $N=20$ daughter nucleus, ${}^{33}\mathrm{Al}$, are found to have nearly $2p-2h$ intruder configuration, thus extending the “island of inversion” beyond Mg. The allowed direct $\beta$-decay branch to the $5/2^{+}$ ground state of the daughter nucleus ${}^{33}\mathrm{Al}$ implies positive parity for the ground state of the parent ${}^{33}\mathrm{Mg}$, contrary to an earlier suggestion of negative parity from a $g$-factor measurement. An admixture of $1p\mathrm{\text{−}}1h$ and $3p\mathrm{\text{−}}3h$ configurations is proposed for the ground state of ${}^{33}\mathrm{Mg}$ to explain all of the experimental observables.

Nuclides in the vicinity of ${}^{94}\mathrm{Ag}$ have been studied with the Penning trap mass spectrometer JYFLTRAP at the Ion-Guide Isotope Separator On-Line. The masses of the two-proton-decay daughter ${}^{92}\mathrm{Rh}$ and the beta-decay daughter ${}^{94}\mathrm{Pd}$ of the high-spin isomer in ${}^{94}\mathrm{Ag}$ have been measured, and the masses of ${}^{93}\mathrm{Pd}$ and ${}^{94}\mathrm{Ag}$ have been deduced. When combined with the data from the one-proton- or two-proton-decay experiments, the results lead to contradictory mass excess values for the high-spin isomer in ${}^{94}\mathrm{Ag}$, $-46370(170)$ or $-44970(100)\mathrm{keV}$, corresponding to excitation energies of 6960(400) or 8360(370) keV, respectively.

The $\gamma$ decay associated with the warm rotation of the superdeformed nuclei ${}^{151}\mathrm{Tb}$ and ${}^{196}\mathrm{Pb}$ has been measured with the EUROBALL IV array. Several independent quantities provide a stringent test of the population and decay dynamics in the superdeformed well. A Monte Carlo simulation of the $\gamma$ decay based on microscopic calculations gives remarkable agreement with the data only assuming a large enhancement of the $B(E1)$ strength for 1–2 MeV $\gamma$ rays, which may be related to the evidence for octupole vibrations in both mass regions.

A novel way of determining the Hamiltonian of the interacting boson model (IBM) is proposed. Based on the fact that the potential energy surface of the mean-field model, e.g., the Skyrme model, can be simulated by that of the IBM, parameters of the IBM Hamiltonian are obtained. By this method, the multifermion dynamics of surface deformation can be mapped, in a good approximation, onto a boson system. The validity of this process is examined for Sm and Ba isotopes, and an application is presented to an unexplored territory of the nuclear chart, namely, the right lower corner of ${}^{208}\mathrm{Pb}$.

The electric quadrupole moment and the magnetic moment of the ${}^{11}\mathrm{Li}$ halo nucleus have been measured with more than an order of magnitude higher precision than before, $|Q|=33.3(5)\mathrm{mb}$ and $\mu =+3.6712(3){\mu }_N$, revealing a 8.8(1.5)% increase of the quadrupole moment relative to that of ${}^9\mathrm{Li}$. This result is compared to various models that aim at describing the halo properties. In the shell model an increased quadrupole moment points to a significant occupation of the $1d$ orbits, whereas in a simple halo picture this can be explained by relating the quadrupole moments of the proton distribution to the charge radii. Advanced models so far fail to reproduce simultaneously the trends observed in the radii and quadrupole moments of the lithium isotopes.

We present a quantum Monte Carlo study of the zero-temperature equation of state of neutron matter and the computation of the ${}^{1}S_0$ pairing gap in the low-density regime with $\rho <0.04{\mathrm{fm}}^{-3}$. The system is described by a nonrelativistic nuclear Hamiltonian including both two- and three-nucleon interactions of the Argonne and Urbana type. This model interaction provides very accurate results in the calculation of the binding energy of light nuclei. A suppression of the gap with respect to the pure BCS theory is found, but sensibly weaker than in other works that attempt to include polarization effects in an approximate way.

The presence of a critical point in the QCD phase diagram can deform the trajectories describing the evolution of the expanding fireball in the ${\mu }_B-T$ phase diagram. If the average emission time of hadrons is a function of transverse velocity, as microscopic simulations of the hadronic freeze-out dynamics suggest, the deformation of the hydrodynamic trajectories will change the transverse velocity (${\beta }_T$) dependence of the proton-antiproton ratio when the fireball passes in the vicinity of the critical point. An unusual ${\beta }_T$ dependence of the $\overline{p}/p$ ratio in a narrow beam energy window would thus signal the presence of the critical point.

A general new technique to solve the two-center problem with arbitrarily oriented deformed realistic potentials is demonstrated, which is based on the powerful potential separable expansion method. As an example, molecular single-particle spectra for ${}^{12}\mathrm{C}+{}^{12}\mathrm{C}\to {}^{24}\mathrm{Mg}$ are calculated using deformed Woods-Saxon potentials. These clearly show that nonaxial symmetric configurations play a crucial role in molecular resonances observed in reaction processes for this system at low energy.

For the first time a fully self-consistent charge-exchange relativistic RPA based on the relativistic Hartree-Fock (RHF) approach is established. The self-consistency is verified by the so-called isobaric analog state (IAS) check. The excitation properties and the nonenergy weighted sum rules of two important charge-exchange excitation modes, the Gamow-Teller resonance (GTR) and the spin-dipole resonance (SDR), are well reproduced in the doubly magic nuclei ${}^{48}\mathrm{Ca}$, ${}^{90}\mathrm{Zr}$ and ${}^{208}\mathrm{Pb}$ without readjustment of the particle-hole residual interaction. The dominant contribution of the exchange diagrams is demonstrated.

Yields for $J/\psi$ production in $\mathrm{Cu}+\mathrm{Cu}$ collisions at $\sqrt{s_{NN}}=200\mathrm{GeV}$ have been measured over the rapidity range $|y|<2.2$ and compared with results in $p+p$ and $\mathrm{Au}+\mathrm{Au}$ collisions at the same energy. The $\mathrm{Cu}+\mathrm{Cu}$ data offer greatly improved precision over existing $\mathrm{Au}+\mathrm{Au}$ data for $J/\psi$ production in collisions with small to intermediate numbers of participants, in the range where the quark-gluon plasma transition threshold is predicted to lie. Cold nuclear matter estimates based on ad hoc fits to $d+\mathrm{Au}$ data describe the $\mathrm{Cu}+\mathrm{Cu}$ data up to $N_{\mathrm{part}}\sim 50$, corresponding to a Bjorken energy density of at least $1.5\mathrm{GeV}/{\mathrm{fm}}^3$.

At finite temperatures and low densities, nuclei may undergo a phase change similar to a classical liquid-gas phase transition. Temperature is the control parameter while density and pressure are the conjugate variables. In the nucleus the difference between the proton and neutron concentrations acts as an additional order parameter, for which the symmetry potential is the conjugate variable. We present experimental results which reveal the $N/Z$ dependence of the phase transition and discuss possible implications of these observations in terms of the Landau free energy description of critical phenomena.