We devise a test of the chiral magnetic and chiral vortical effects (CME and CVE) in relativistic heavy ion collisions that relies only on the general properties of triangle anomalies. We show that the ratio $R_{EB}=J_E/J_B$ of charge $J_E$ and baryon $J_B$ currents for CME is $R_{EB}^{\mathrm{CME}}\to \infty$ for three light flavors of quarks ($N_f=3$), and $R_{EB}^{\mathrm{CME}}=5$ for $N_f=2$, whereas for CVE it is $R_{EB}^{\mathrm{CVE}}=0$ for $N_f=3$ and $R_{EB}^{\mathrm{CME}}=1/2$ for $N_f=2$. The physical world with light $u,d$ quarks and a heavier $s$ quark is in between the $N_f=2$ and $N_f=3$ cases; therefore, the ratios $R_{EB}$ for CME and CVE should differ by over an order of magnitude providing a possibility to separate clearly the CME and CVE contributions. In both cases, there has to be a positive correlation between the charge and baryon number asymmetries that can be tested on the event-by-event basis.

This Letter shows quantitatively that the magnitude of the EMC effect measured in electron deep inelastic scattering at intermediate $x_B$, $0.35\le x_B\le 0.7$, is linearly related to the short range correlation (SRC) scale factor obtained from electron inclusive scattering at $x_B\ge 1$. The observed phenomenological relationship is used to extract the ratio of the deuteron to the free $pn$ pair cross sections and $F_2^n/F_2^p$, the ratio of the free neutron to free proton structure functions. We speculate that the observed correlation is because both the EMC effect and SRC are dominated by the high virtuality (high momentum) nucleons in the nucleus.

In the search for the nuclide with the largest probability for neutrinoless double-electron capture, we have determined the $Q_{ϵϵ}$ value between the ground states of ${}^{152}\mathrm{Gd}$ and ${}^{152}\mathrm{Sm}$ by Penning-trap mass-ratio measurements. The new $Q_{ϵϵ}$ value of 55.70(18) keV results in a half-life of ${10}^{26}\mathrm{yr}$ for a 1 eV neutrino mass. With this smallest half-life among known $0\nu ϵϵ$ transitions, ${}^{152}\mathrm{Gd}$ is a promising candidate for the search for neutrinoless double-electron capture.

The $\beta$-decay half-lives of 38 neutron-rich isotopes from ${}_{36}\mathrm{Kr}$ to ${}_{43}\mathrm{Tc}$ have been measured; the half-lives of ${}^{100}\mathrm{Kr}$, ${}^{103–105}\mathrm{Sr}$, ${}^{106–108}\mathrm{Y}$, ${}^{108–110}\mathrm{Zr}$, ${}^{111,112}\mathrm{Nb}$, ${}^{112–115}\mathrm{Mo}$, and ${}^{116,117}\mathrm{Tc}$ are reported here. The results when compared with previous standard models indicate an overestimation in the predicted half-lives by a factor of 2 or more in the $A\approx 110$ region. A revised model based on the second generation gross theory of $\beta$ decay better predicts the measured half-lives and suggests a more rapid flow of the rapid neutron-capture process ($r$-matter flow) through this region than previously predicted.

In-source resonant ionization laser spectroscopy of the even-$A$ polonium isotopes ${}^{192–210,216,218}\mathrm{Po}$ has been performed using the $6p^{3}7s$ ${}^{5}S_2$ to $6p^{3}7p$ ${}^{5}P_2$ ($\lambda =843.38\mathrm{nm}$) transition in the polonium atom (Po-I) at the CERN ISOLDE facility. The comparison of the measured isotope shifts in ${}^{200–210}\mathrm{Po}$ with a previous data set allows us to test for the first time recent large-scale atomic calculations that are essential to extract the changes in the mean-square charge radius of the atomic nucleus. When going to lighter masses, a surprisingly large and early departure from sphericity is observed, which is only partly reproduced by beyond mean field calculations.

The inhibition of fusion by quasifission is crucial in limiting the formation of superheavy elements in collisions of heavy nuclei. Time scales of $\sim {10}^{-18}\mathrm{s}$ inferred for fissionlike events from recent crystal blocking measurements were interpreted to show either that quasifission itself is slower than previously believed, or that the fraction of slow fusion-fission is higher than expected. New measurements of mass-angle distributions for ${}^{48}\mathrm{Ti}$ and ${}^{64}\mathrm{Ni}$ bombarding W targets show that in these reactions quasifission is the dominant process, typically occurring before the system formed after contact has made a single rotation, corresponding to time scales of $\le {10}^{-20}\mathrm{s}$.

We measured with unprecedented precision the induced polarization $P_y$ in ${}^4\mathrm{He}(e,e^{\prime }\overrightarrow{p}){}^3\mathrm{H}$ at $Q^2=0.8$ and $1.3(\mathrm{GeV}/c{)}^2$. The induced polarization is indicative of reaction-mechanism effects beyond the impulse approximation. Our results are in agreement with a relativistic distorted-wave impulse approximation calculation but are overestimated by a calculation with strong charge-exchange effects. Our data are used to constrain the strength of the spin-independent charge-exchange term in the latter calculation.

We present results for the elliptic and triangular flow coefficients $v_2$ and $v_3$ in $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{s}=200A\mathrm{GeV}$ using event-by-event $\mathrm{D}=3+1$ viscous hydrodynamic simulations. We study the effect of initial state fluctuations and finite viscosities on the flow coefficients $v_2$ and $v_3$ as functions of transverse momentum and pseudorapidity. Fluctuations are essential to reproduce the measured centrality dependence of elliptic flow. We argue that simultaneous measurements of $v_2$ and $v_3$ can determine $\eta /s$ more precisely.

The radiative capture cross sections for the ${}^3\mathrm{He}(\alpha ,\gamma ){}^7\mathrm{Be}$ and ${}^3\mathrm{H}(\alpha ,\gamma ){}^7\mathrm{Li}$ reactions are calculated in the fully microscopic fermionic molecular dynamics approach using a realistic effective interaction that reproduces the nucleon-nucleon scattering data. At large distances bound and scattering states are described by antisymmetrized products of ${}^4\mathrm{He}$ and ${}^3\mathrm{He}/{}^3\mathrm{H}$ ground states. At short distances the many-body Hilbert space is extended with additional many-body wave functions needed to represent polarized clusters and shell-model-like configurations. Properties of the bound states are described well, as are the scattering phase shifts. The calculated $S$ factor for the ${}^3\mathrm{He}(\alpha ,\gamma ){}^7\mathrm{Be}$ reaction agrees very well with recent experimental data in both absolute normalization and energy dependence. In the case of the ${}^3\mathrm{H}(\alpha ,\gamma ){}^7\mathrm{Li}$ reaction the calculated $S$ factor is larger than available experimental data by about 15%.

We analyze the statistics of resonance widths in a many-body Fermi system with open decay channels. Depending on the strength of continuum coupling, such a system reveals growing deviations from the standard chi-square (Porter-Thomas) width distribution. The deviations emerge from the process of increasing interaction of intrinsic states through common decay channels; in the limit of perfect coupling this process leads to the superradiance phase transition. The width distribution depends also on the intrinsic dynamics (chaotic versus regular). The results presented here are important for understanding the recent experimental data concerning the width distribution for neutron resonances in nuclei.

A high-precision half-life measurement for the superallowed ${\beta }^{+}$ emitter ${}^{26}\mathrm{Al}^m$ was performed at the TRIUMF-ISAC radioactive ion beam facility yielding $T_{1/2}=6346.54\pm {0.46}_{\mathrm{stat}}\pm {0.60}_{\mathrm{syst}}\mathrm{ms}$, consistent with, but 2.5 times more precise than, the previous world average. The ${}^{26}\mathrm{Al}^m$ half-life and $ft$ value, 3037.53(61) s, are now the most precisely determined for any superallowed $\beta$ decay. Combined with recent theoretical corrections for isospin-symmetry-breaking and radiative effects, the corrected $\mathcal{F}t$ value for ${}^{26}\mathrm{Al}^m$, 3073.0(12) s, sets a new benchmark for the high-precision superallowed Fermi $\beta$-decay studies used to test the conserved vector current hypothesis and determine the $V_{ud}$ element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix.

The centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76\mathrm{TeV}$ is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor of 2 from peripheral (70%–80%) to central (0%–5%) collisions. The centrality dependence is found to be similar to that observed at lower collision energies. The data are compared with models based on different mechanisms for particle production in nuclear collisions.

The transition rates for the $2_1^{+}$ states in ${}^{62,64,66}\mathrm{Fe}$ were studied using the recoil distance Doppler-shift technique applied to projectile Coulomb excitation reactions. The deduced $E2$ strengths illustrate the enhanced collectivity of the neutron-rich Fe isotopes up to $N=40$. The results are interpreted using the generalized concept of valence proton symmetry which describes the evolution of nuclear structure around $N=40$ as governed by the number of valence protons with respect to $Z\approx 30$. The trend of collectivity suggested by the experimental data is described by state-of-the-art shell-model calculations with a new effective interaction developed for the $fpgd$ valence space.

Two widely proposed $k_t$-dependent gluon distributions in the small-$x$ saturation regime are investigated using two-particle back-to-back correlations in high energy scattering processes. The Weizsäcker-Williams gluon distribution, interpreted as the number density of gluon inside nucleus, is studied in the quark-antiquark jet correlation in deep inelastic scattering. On the other hand, the unintegrated gluon distribution, defined as the Fourier transform of the color-dipole cross section, is probed in the direct photon-jet correlation in $pA$ collisions.

The heavy cluster knockout reaction ${}^{16}\mathrm{O}({}^{12}\mathrm{C},2{}^{12}\mathrm{C}){}^4\mathrm{He}$ performed for the first time, reveals the true nature of the ${}^{12}\mathrm{C}\mathrm{\text{−}}{}^{12}\mathrm{C}$ interaction. The observed cross section is enhanced by almost 2 orders of magnitude over the conventional zero range distorted wave impulse approximation (DWIA) predictions. An attractive ${}^{12}\mathrm{C}\mathrm{\text{−}}{}^{12}\mathrm{C}$ optical potential, as obtained in the folding model, does not explain the enhanced cross section in the finite range (FR) DWIA framework. The inclusion of a hard core of fairly long range $\sim 3.65\mathrm{fm}$ explains the data. The present investigation of ${}^{16}\mathrm{O}({}^{12}\mathrm{C},2{}^{12}\mathrm{C}){}^4\mathrm{He}$ along with the ${}^{12}\mathrm{C}\mathrm{\text{−}}{}^{12}\mathrm{C}$ elastic scattering also proves beyond doubt that the folding model’s deep attractive heavy ion potentials are unsuitable to describe the highly overlapping heavy ions. The application of FR-DWIA opens up new avenues to use the heavy core knockout for the detailed investigation of heavy as well as Borromean halo nuclei.

Medium excitation by jet shower propagation inside a quark-gluon plasma is studied within a linear Boltzmann transport and a multiphase transport model. Contrary to the naive expectation, it is the deflection of both the jet shower and the Mach-cone-like excitation in an expanding medium that is found to give rise to a double-peak azimuthal particle distribution with respect to the initial jet direction. Such a deflection is the strongest for hadron-triggered jets which are often produced close to the surface of a dense medium due to trigger bias and travel against or tangential to the radial flow. Without such trigger bias, the effect of deflection on $\gamma$-jet showers and their medium excitation is weaker. Comparative study of hadron and $\gamma$-triggered particle correlations can therefore reveal the dynamics of jet-induced medium excitation in high-energy heavy-ion collisions.

The properties of inhomogeneous neutron matter are crucial to the physics of neutron-rich nuclei and the crust of neutron stars. Advances in computational techniques now allow us to accurately determine the binding energies and densities of many neutrons interacting via realistic microscopic interactions and confined in external fields. We perform calculations for different external fields and across several shells to place important constraints on inhomogeneous neutron matter, and hence the large isospin limit of the nuclear energy density functionals that are used to predict properties of heavy nuclei and neutron star crusts. We find important differences between microscopic calculations and current density functionals; in particular, the isovector gradient terms are significantly more repulsive than in traditional models, and the spin-orbit and pairing forces are comparatively weaker.

The electric form factor of the neutron was determined from studies of the reaction ${\mathrm{}}^3\overrightarrow{\mathrm{He}}(\overrightarrow{e},e^{\prime }n)pp$ in quasielastic kinematics in Hall A at Jefferson Lab. Longitudinally polarized electrons were scattered off a polarized target in which the nuclear polarization was oriented perpendicular to the momentum transfer. The scattered electrons were detected in a magnetic spectrometer in coincidence with neutrons that were registered in a large-solid-angle detector. More than doubling the $Q^2$ range over which it is known, we find $G_E^n=0.0236\pm 0.0017(\mathrm{stat})\pm 0.0026(\mathrm{syst})$, $0.0208\pm 0.0024\pm 0.0019$, and $0.0147\pm 0.0020\pm 0.0014$ for $Q^2=1.72$, 2.48, and $3.41{\mathrm{GeV}}^2$, respectively.

Zero-range effective interactions are commonly used in nuclear physics and in other domains to describe many-body systems within the mean-field model. If they are used within a beyond-mean-field framework, contributions to the total energy that display an ultraviolet divergence are found. We propose a general strategy to regularize this divergence and we illustrate it in the case of the second-order corrections to the equation of state (EOS) of uniform symmetric matter. By setting a momentum cutoff $\Lambda$, we show that for every (physically meaningful) value of $\Lambda$ it is possible to determine a new interaction such that the EOS with the second-order corrections reproduces the empirical EOS, with a fit of the same quality as that obtained at the mean-field level.

We present a successful description of the medium modification of light and heavy flavor jets within a perturbative-QCD-based approach. Only the couplings involving hard partons are assumed to be weak. The effect of the medium on a hard parton, per unit time, is encoded in terms of three nonperturbative, related transport coefficients which describe the transverse momentum squared gained, the elastic energy loss, and diffusion in elastic energy transfer. Scaling the transport coefficients with the temperature of the medium, we achieve a good description of the centrality dependence of the suppression and the azimuthal anisotropy of leading hadrons. Imposing additional constraints based on leading order (LO) hard thermal loop (HTL) effective theory leads to a worsening of the fit, implying the necessity of computing transport coefficients beyond LO HTL.