We examine baryonic matter at a quark chemical potential of the order of the confinement scale ${\mu }_q\sim {\Lambda }_{\mathrm{QCD}}$. In this regime, quarks are supposed to be confined but baryons are close to the “tightly packed limit” where they nearly overlap in configuration space. We show that this system will exhibit a percolation phase transition when varied in the number of colors $N_c$: at high $N_c$, large distance correlations at the quark level are possible even if the quarks are essentially confined. At low $N_c$, this does not happen. We discuss the relevance of this for dense nuclear matter, and argue that our results suggest a new “phase transition,” varying $N_c$ at constant ${\mu }_q$.

We present measurements of $J/\psi$ yields in $d+\mathrm{Au}$ collisions at $\sqrt{s_{NN}}=200\mathrm{GeV}$ recorded by the PHENIX experiment and compare them with yields in $p+p$ collisions at the same energy per nucleon-nucleon collision. The measurements cover a large kinematic range in $J/\psi$ rapidity ($-2.2<y<2.4$) with high statistical precision and are compared with two theoretical models: one with nuclear shadowing combined with final state breakup and one with coherent gluon saturation effects. In order to remove model dependent systematic uncertainties we also compare the data to a simple geometric model. The forward rapidity data are inconsistent with nuclear modifications that are linear or exponential in the density weighted longitudinal thickness, such as those from the final state breakup of the bound state.

The ${}^2\mathrm{H}(d,p){}^3\mathrm{H}$, ${}^2\mathrm{H}(d,n){}^3\mathrm{He}$, and ${}^2\mathrm{H}(d,\gamma ){}^4\mathrm{He}$ reactions are studied at low energies in a multichannel ab initio model that takes into account the distortions of the nuclei. The internal wave functions of these nuclei are given by the stochastic variational method with the $\mathrm{AV}{8}^{\prime }$ realistic interaction and a phenomenological three-body force included to reproduce the two-body thresholds. The obtained astrophysical $S$ factors are all in very good agreement with the experiment. The most important channels for both transfer and radiative capture are identified by comparing to calculations with an effective central force. They are all found to dominate thanks to the tensor force.

I compute the thermal suppression of the ${\rm Y}(1s)$ and ${\chi }_{b1}$ states in $\sqrt{s_{NN}}=2.76\mathrm{TeV}$ Pb-Pb collisions. Using the suppression of each of these states I estimate the total $R_{AA}$ for the ${\rm Y}(1s)$ state as a function of centrality, rapidity, and transverse momentum. I find less suppression of the ${\chi }_{b1}$ state than would be traditionally assumed; however, my final results for the total ${\rm Y}(1s)$ suppression are in good agreement with recent preliminary CMS data.

We examine nuclear scission within a fully quantum-mechanical microscopic framework, focusing on the nonlocal aspects of the theory. Using ${}^{240}\mathrm{Pu}$ hot fission as an example, we discuss the identification of the fragments and the calculation of their kinetic, excitation, and interaction energies, through the localization of the orbital wave functions. We show that the disentanglement of the fragment wave functions is essential to the quantum-mechanical definition of scission and the calculation of physical observables. Finally, we discuss the fragments’ prescission excitation mechanisms and give a nonadiabatic description of their evolution beyond scission.

For the first time the differential cross section for the elastic neutron-triton ($n\mathrm{\text{−}}{}^3\mathrm{H}$) and neutron-deuteron ($n\mathrm{\text{−}}{}^2\mathrm{H}$) scattering at 14.1 MeV has been measured by using an inertial confinement fusion facility. In these experiments, which were carried out by simultaneously measuring elastically scattered ${}^3\mathrm{H}$ and ${}^2\mathrm{H}$ ions from a deuterium-tritium gas-filled inertial confinement fusion capsule implosion, the differential cross section for the elastic $n\mathrm{\text{−}}{}^3\mathrm{H}$ scattering was obtained with significantly higher accuracy than achieved in previous accelerator experiments. The results compare well with calculations that combine the resonating-group method with an ab initio no-core shell model, which demonstrate that recent advances in ab initio theory can provide an accurate description of light-ion reactions.

Covariant density functional theory and the tilted axis cranking method are used to investigate antimagnetic rotation (AMR) in nuclei for the first time in a fully self-consistent and microscopic way. The experimental spectrum as well as the $B(E2)$ values of the recently observed AMR band in ${}^{105}\mathrm{Cd}$ are reproduced very well. This gives a further strong hint that AMR is realized in specific bands in nuclei.

We investigate the linear chain configurations of four-$\alpha$ clusters in ${}^{16}\mathrm{O}$ using a Skyrme cranked Hartree-Fock method and discuss the relationship between the stability of such states and angular momentum. We show the existence of a region of angular momentum ($13–18\hslash$) where the linear chain configuration is stabilized. For the first time we demonstrate that stable exotic states with a large moment of inertia (${\hslash }^2/2\Theta \sim 0.06–0.08\mathrm{MeV}$) can exist.

We report the results of an improved determination of the triple correlation $D\mathbf{P}·({\mathbf{p}}_{\mathbf{e}}\times {\mathbf{p}}_{\mathbf{v}})$ that can be used to limit possible time-reversal invariance in the beta decay of polarized neutrons and constrain extensions to the standard model. Our result is $D=[-0.96\pm 1.89(\mathrm{stat})\pm 1.01(\mathrm{sys})]\times {10}^{-4}$. The corresponding phase between $g_A$ and $g_V$ is ${\varphi }_{AV}=180.013°\pm 0.028°$ (68% confidence level). This result represents the most sensitive measurement of $D$ in nuclear $\beta$ decay.

The two protons emitted in the decay of ${}^{54}\mathrm{Zn}$ have been individually observed for the first time in a time projection chamber. The total decay energy and the half-life measured in this work agree with the results obtained in a previous experiment. Angular and energy correlations between the two protons are determined and compared to theoretical distributions of a three-body model. Within the shell model framework, the relative decay probabilities show a strong contribution of the $p^2$ configuration for the two-proton emission. After ${}^{45}\mathrm{Fe}$, the present result on ${}^{54}\mathrm{Zn}$ constitutes only the second case of a direct observation of the ground state two-proton decay of a long-lived isotope.

Establishing how and when large $N/Z$ values require modified or new theoretical tools is a major quest in nuclear physics. Here we report the first measurement of the lifetime of the $2_1^{+}$ state in the near-dripline nucleus ${}^{20}\mathrm{C}$. The deduced value of ${\tau }_{2_1^{+}}=9.8\pm 2.8(\mathrm{stat}{)}_{-1.1}^{+0.5}(\mathrm{syst})\mathrm{ps}$ gives a reduced transition probability of $B(E2;2_1^{+}\to 0_{\mathrm{g}.\mathrm{s}.}^{+})={7.5}_{-1.7}^{+3.0}(\mathrm{stat}{)}_{-0.4}^{+1.0}(\mathrm{syst}){\mathrm{e}}^2{\mathrm{fm}}^4$ in good agreement with a shell model calculation using isospin-dependent effective charges.

Fusion cross sections were measured for the exotic proton-halo nucleus ${}^8\mathrm{B}$ incident on a ${}^{58}\mathrm{Ni}$ target at several energies near the Coulomb barrier. This is the first experiment to report on the fusion of a proton-halo nucleus. The resulting excitation function shows a striking enhancement with respect to expectations for normal projectiles. Evidence is presented that the sum of the fusion and breakup yields saturates the total reaction cross section.

Absolute values of two-particle transfer cross sections along the Sn-isotopic chain are calculated. They agree with measurements within errors and without free parameters. Within this scenario, the predictions concerning the absolute value of the two-particle transfer cross sections associated with the excitation of the pairing vibrational spectrum expected around the recently discovered closed shell nucleus ${}_{50}{}^{132}\mathrm{Sn}_{82}$ and the very exotic nucleus ${}_{50}{}^{100}\mathrm{Sn}_{50}$ can be considered quantitative, opening new perspectives in the study of pairing in nuclei.

We present first ab initio no-core shell model (NCSM) calculations using similarity renormalization group (SRG) transformed chiral two-nucleon ($NN$) plus three-nucleon ($3N$) interactions for nuclei throughout the $p$-shell, particularly ${}^{12}\mathrm{C}$ and ${}^{16}\mathrm{O}$. By introducing an adaptive importance truncation for the NCSM model space and an efficient $JT$-coupling scheme for the $3N$ matrix elements, we are able to surpass previous NCSM studies including $3N$ interactions. We present ground and excited states in ${}^{12}\mathrm{C}$ and ${}^{16}\mathrm{O}$ for model spaces up to $N_{\max }=12$ including full $3N$ interactions. We analyze the contributions of induced and initial $3N$ interactions and probe induced $4N$ terms through the sensitivity of the energies on the SRG flow parameter. Unlike for light $p$-shell nuclei, SRG-induced $4N$ contributions originating from the long-range two-pion terms of the chiral $3N$ interaction are sizable in ${}^{12}\mathrm{C}$ and ${}^{16}\mathrm{O}$.

The concept of heavy-particle radioactivity (HPR) is changed to allow emitted particles with $Z_e>28$ from parents with $Z>110$ and daughter around ${}^{208}\mathrm{Pb}$. Calculations for superheavy (SH) nuclei with $Z=104–124$ are showing a trend toward shorter half-lives and larger branching ratio relative to $\alpha$ decay for heavier SHs. It is possible to find regions in which HPR is stronger than alpha decay. The new mass table AME11 and the theoretical KTUY05 and FRDM95 masses are used to determine the released energy. For 124 we found isotopes with half-lives in the range of ns to ps.

We report results from the NEMO-3 experiment based on an exposure of 1275 days with 661 g of ${}^{130}\mathrm{Te}$ in the form of enriched and natural tellurium foils. The $\beta \beta$ decay rate of ${}^{130}\mathrm{Te}$ is found to be greater than zero with a significance of 7.7 standard deviations and the half-life is measured to be $T_{1/2}^{2\nu }=[7.0\pm 0.9(\mathrm{stat})\pm 1.1(\mathrm{syst})]\times {10}^{20}\mathrm{yr}$. This represents the most precise measurement of this half-life yet published and the first real-time observation of this decay.

A benchmark experiment on ${}^{208}\mathrm{Pb}$ shows that polarized proton inelastic scattering at very forward angles including 0° is a powerful tool for high-resolution studies of electric dipole ($E1$) and spin magnetic dipole ($M1$) modes in nuclei over a broad excitation energy range to test up-to-date nuclear models. The extracted $E1$ polarizability leads to a neutron skin thickness $r_{\mathrm{skin}}={0.156}_{-0.021}^{+0.025}\mathrm{fm}$ in ${}^{208}\mathrm{Pb}$ derived within a mean-field model [Phys. Rev. C 81, 051303 (2010)], thereby constraining the symmetry energy and its density dependence relevant to the description of neutron stars.

We show that chiral effective field theory (EFT) two-body currents provide important contributions to the quenching of low-momentum-transfer Gamow-Teller transitions, and use chiral EFT to predict the momentum-transfer dependence that is probed in neutrinoless double-beta ($0\nu \beta \beta$) decay. We then calculate for the first time the $0\nu \beta \beta$ decay operator based on chiral EFT currents and study the nuclear matrix elements at successive orders. The contributions from chiral two-body currents are significant and should be included in all calculations.

The chiral magnetic wave is a gapless collective excitation of quark-gluon plasma in the presence of an external magnetic field that stems from the interplay of chiral magnetic and chiral separation effects; it is composed of the waves of the electric and chiral charge densities coupled by the axial anomaly. We consider a chiral magnetic wave at finite baryon density and find that it induces the electric quadrupole moment of the quark-gluon plasma produced in heavy ion collisions: the “poles” of the produced fireball (pointing outside of the reaction plane) acquire additional positive electric charge, and the “equator” acquires additional negative charge. We point out that this electric quadrupole deformation lifts the degeneracy between the elliptic flows of positive and negative pions leading to $v_2({\pi }^{+})<v_2({\pi }^{-})$, and estimate the magnitude of the effect.

A comparison of the relative yields of ${\rm Y}$ resonances in the ${\mu }^{+}{\mu }^{-}$ decay channel in Pb-Pb and $pp$ collisions at a center-of-mass energy per nucleon pair of 2.76 TeV is performed with data collected with the CMS detector at the LHC. Using muons of transverse momentum above $4\mathrm{GeV}/c$ and pseudorapidity below 2.4, the double ratio of the ${\rm Y}(2S)$ and ${\rm Y}(3S)$ excited states to the ${\rm Y}(1S)$ ground state in Pb-Pb and $pp$ collisions, $[{\rm Y}(2S+3S)/{\rm Y}(1S){]}_{\mathrm{Pb}\mathrm{\text{−}}\mathrm{Pb}}/[{\rm Y}(2S+3S)/{\rm Y}(1S){]}_{pp}$, is found to be ${0.31}_{-0.15}^{+0.19}(\mathrm{stat})\pm 0.03(\mathrm{syst})$. The probability to obtain the measured value, or lower, if the true double ratio is unity, is calculated to be less than 1%.