We investigate the close connection between the quantum phase space Wigner distribution of small-$x$ gluons and the color dipole scattering amplitude, and we propose studying it experimentally in the hard diffractive dijet production at the planned electron-ion collider. The angular correlation between the nucleon recoiled momentum and the dijet transverse momentum probes the nontrivial correlation in the phase space Wigner distribution. This experimental study not only provides us with three-dimensional tomographic pictures of gluons inside high energy protons—it gives a unique and interesting signal for the small-$x$ dynamics with QCD evolution effects.

The formalism based on factorization and nuclear spectral functions has been generalized to treat transition matrix elements involving two-nucleon currents, whose contribution to the nuclear electromagnetic response in the transverse channel is known to be significant. We report the results of calculations of the inclusive electron-carbon cross section, showing that the inclusion of processes involving two-nucleon currents appreciably improves the agreement between theory and data in the dip region, between the quasielastic and $\mathrm{\Delta }$-production peaks. The relation to approaches based on the independent particle of the nucleus and the implications for the analysis of flux-integrated neutrino-nucleus cross sections are discussed.

Precision measurements of superallowed Fermi $\beta$-decay transitions, particularly for the lightest superallowed emitters ${}^{10}\mathrm{C}$ and ${}^{14}\mathrm{O}$, set stringent limits on possible scalar current contributions to the weak interaction. In the present work, a discrepancy between recent measurements of the ${}^{10}\mathrm{C}$ half-life is addressed through two high-precision half-life measurements, via $\gamma$-ray photopeak and $\beta$ counting, that yield consistent results for the ${}^{10}\mathrm{C}$ half-life of $T_{1/2}=19.2969\pm 0.0074\mathrm{s}$ and $T_{1/2}=19.3009\pm 0.0017\mathrm{s}$, respectively. The latter is the most precise superallowed $\beta$-decay half-life measurement reported to date and the first to achieve a relative precision below ${10}^{-4}$. A fit to the world superallowed $\beta$-decay data including the ${}^{10}\mathrm{C}$ half-life measurements reported here yields $b_F=-0.0018\pm 0.0021$ (68% C.L.) for the Fierz interference term and $C_S/C_V=+0.0009\pm 0.0011$ for the ratio of the weak scalar to vector couplings assuming left-handed neutrinos.

Results on two-particle angular correlations for charged particles produced in $pp$ collisions at a center-of-mass energy of 13 TeV are presented. The data were taken with the CMS detector at the LHC and correspond to an integrated luminosity of about $270{\mathrm{nb}}^{-1}$. The correlations are studied over a broad range of pseudorapidity ($|\eta |<2.4$) and over the full azimuth ($\varphi$) as a function of charged particle multiplicity and transverse momentum ($p_{\mathrm{T}}$). In high-multiplicity events, a long-range ($|\mathrm{\Delta }\eta |>2.0$), near-side ($\mathrm{\Delta }\varphi \approx 0$) structure emerges in the two-particle $\mathrm{\Delta }\eta$–$\mathrm{\Delta }\varphi$ correlation functions. The magnitude of the correlation exhibits a pronounced maximum in the range $1.0<p_{\mathrm{T}}<2.0\mathrm{GeV}/c$ and an approximately linear increase with the charged particle multiplicity, with an overall correlation strength similar to that found in earlier $pp$ data at $\sqrt{s}=7\mathrm{TeV}$. The present measurement extends the study of near-side long-range correlations up to charged particle multiplicities $N_{\mathrm{ch}}\sim 180$, a region so far unexplored in $pp$ collisions. The observed long-range correlations are compared to those seen in $pp$, $p\mathrm{Pb}$, and PbPb collisions at lower collision energies.

Several new isotopes, ${}^{96}\mathrm{In}$, ${}^{94}\mathrm{Cd}$, ${}^{92}\mathrm{Ag}$, and ${}^{90}\mathrm{Pd}$, have been identified at the RIKEN Nishina Center. The study of proton drip-line nuclei in the vicinity of ${}^{100}\mathrm{Sn}$ led to the discovery of new proton emitters ${}^{93}\mathrm{Ag}$ and ${}^{89}\mathrm{Rh}$ with half-lives in the submicrosecond range. The systematics of the half-lives of odd-$Z$ nuclei with $T_z=-1/2$ toward ${}^{99}\mathrm{Sn}$ shows a stabilizing effect of the $Z=50$ shell closure. Production cross sections for nuclei in the vicinity of ${}^{100}\mathrm{Sn}$ measured at different energies and target thicknesses were compared to the cross sections calculated by epax taking into account contributions of secondary reactions in the primary target.

We generalize the problem of strongly interacting neutron matter by adding a periodic external modulation. This allows us to study from first principles a neutron system that is extended and inhomogeneous, with connections to the physics of both neutron-star crusts and neutron-rich nuclei. We carry out fully nonperturbative microscopic quantum Monte Carlo calculations of the energy of neutron matter at different densities, as well as different strengths and periodicities of the external potential. In order to remove systematic errors, we examine finite-size effects and the impact of the wave function ansatz. We also make contact with energy-density functional theories of nuclei and disentangle isovector gradient contributions from bulk properties. Finally, we calculate the static density-density linear response function of neutron matter and compare it with the response of other physical systems.

We show that the Nambu-Goldstone formalism of the broken gauge symmetry in the presence of the $T=1$ pairing condensate offers a quantitative description of the binding-energy differences of open-shell superfluid nuclei. We conclude that the pairing-rotational moments of inertia are excellent pairing indicators, which are free from ambiguities attributed to odd-mass systems. We offer a new, unified interpretation of the binding-energy differences traditionally viewed in the shell model picture as signatures of the valence nucleon properties. We present the first systematic analysis of the off-diagonal pairing-rotational moments of inertia and demonstrate the mixing of the neutron and proton pairing-rotational modes in the ground states of even-even nuclei. Finally, we discuss the importance of mass measurements of neutron-rich nuclei for constraining the pairing energy density functional.

We report the first results of elliptic ($v_2$), triangular ($v_3$), and quadrangular ($v_4$) flow of charged particles in Pb-Pb collisions at a center-of-mass energy per nucleon pair of $\sqrt{s_{NN}}=5.02\mathrm{TeV}$ with the ALICE detector at the CERN Large Hadron Collider. The measurements are performed in the central pseudorapidity region $|\eta |<0.8$ and for the transverse momentum range $0.2<p_T<5\mathrm{GeV}/c$. The anisotropic flow is measured using two-particle correlations with a pseudorapidity gap greater than one unit and with the multiparticle cumulant method. Compared to results from Pb-Pb collisions at $\sqrt{s_{NN}}=2.76\mathrm{TeV}$, the anisotropic flow coefficients $v_2$, $v_3$, and $v_4$ are found to increase by $(3.0\pm 0.6)\%$, $(4.3\pm 1.4)\%$, and $(10.2\pm 3.8)\%$, respectively, in the centrality range 0%–50%. This increase can be attributed mostly to an increase of the average transverse momentum between the two energies. The measurements are found to be compatible with hydrodynamic model calculations. This comparison provides a unique opportunity to test the validity of the hydrodynamic picture and the power to further discriminate between various possibilities for the temperature dependence of shear viscosity to entropy density ratio of the produced matter in heavy-ion collisions at the highest energies.

Fission yields form an integral part of the prediction of antineutrino spectra generated by nuclear reactors, but little attention has been paid to the quality and reliability of the data used in current calculations. Following a critical review of the thermal and fast ENDF/B-VII.1 ${}^{235}\mathrm{U}$ fission yields, deficiencies are identified and improved yields are obtained, based on corrections of erroneous yields, consistency between decay and fission yield data, and updated isomeric ratios. These corrected yields are used to calculate antineutrino spectra using the summation method. An anomalous value for the thermal fission yield of ${}^{86}\mathrm{Ge}$ generates an excess of antineutrinos at 5–7 MeV, a feature which is no longer present when the corrected yields are used. Thermal spectra calculated with two distinct fission yield libraries (corrected ENDF/B and JEFF) differ by up to 6% in the 0–7 MeV energy window, allowing for a basic estimate of the uncertainty involved in the fission yield component of summation calculations. Finally, the fast neutron antineutrino spectrum is calculated, which at the moment can only be obtained with the summation method and may be relevant for short baseline reactor experiments using highly enriched uranium fuel.

We have performed the first direct measurement of the ${}^{38}\mathrm{K}(p,\gamma ){}^{39}\mathrm{Ca}$ reaction using a beam of radioactive ${}^{38}\mathrm{K}$. A proposed $\ell =0$ resonance in the ${}^{38}\mathrm{K}+p$ system has been identified at 679(2) keV with an associated strength of ${120}_{-30}^{+50}\mathrm{meV}$. Upper limits of 1.16 (3.5) and 8.6 (26) meV at the 68% (95%) confidence level were also established for two further expected $\ell =0$ resonances at 386 and 515 keV, respectively. The present results have reduced uncertainties in the ${}^{38}\mathrm{K}(p,\gamma ){}^{39}\mathrm{Ca}$ reaction rate at temperatures of 0.4 GK by more than 2 orders of magnitude and indicate that Ar and Ca may be ejected in observable quantities by oxygen-neon novae. However, based on the newly evaluated rate, the ${}^{38}\mathrm{K}(p,\gamma ){}^{39}\mathrm{Ca}$ path is unlikely to be responsible for the production of Ar and Ca in significantly enhanced quantities relative to solar abundances.

In this contribution it is explored whether $\gamma$-ray spectroscopy following $\beta$ decay with high $Q$ values from mother nuclei with low ground-state spin can be exploited as a probe for the pygmy dipole resonance. The suitability of this approach is demonstrated by a comparison between data from photon scattering, ${}^{136}\mathrm{Xe}(\gamma ,{\gamma }^{\prime })$, and ${}^{136}\mathrm{I}$ $[J_0^{\pi }=(1^{-})]{\to }^{136}{\mathrm{Xe}}^{*}$ $\beta$-decay data. It is demonstrated that $\beta$ decay populates $1^{-}$ levels associated with the pygmy dipole resonance, but only a fraction of those. The complementary insight into the wave functions probed by $\beta$ decay is elucidated by calculations within the quasiparticle phonon model. It is demonstrated that $\beta$ decay dominantly populates complex configurations, which are only weakly excited in inelastic scattering experiments.

Jet production rates are measured in $p+p$ and $d+\mathrm{Au}$ collisions at $\sqrt{s_{NN}}=200\mathrm{GeV}$ recorded in 2008 with the PHENIX detector at the Relativistic Heavy Ion Collider. Jets are reconstructed using the $R=0.3$ anti-$k_t$ algorithm from energy deposits in the electromagnetic calorimeter and charged tracks in multiwire proportional chambers, and the jet transverse momentum ($p_T$) spectra are corrected for the detector response. Spectra are reported for jets with $12<p_T<50\mathrm{GeV}/c$, within a pseudorapidity acceptance of $|\eta |<0.3$. The nuclear-modification factor ($R_{d\mathrm{Au}}$) values for 0%–100% $d+\mathrm{Au}$ events are found to be consistent with unity, constraining the role of initial state effects on jet production. However, the centrality-selected $R_{d\mathrm{Au}}$ values and central-to-peripheral ratios ($R_{\mathrm{CP}}$) show large, $p_T$-dependent deviations from unity, challenging the conventional models that relate hard-process rates and soft-particle production in collisions involving nuclei.

We show that for an anomalous fluid carrying dissipationless chiral magnetic and/or vortical currents there is a frame in which a stationary obstacle experiences no drag, but energy and charge currents do not vanish, resembling superfluidity. However, unlike ordinary superfluid flow, the anomalous chiral currents can transport entropy in this frame. We show that the second law of thermodynamics completely determines the amounts of these anomalous nondissipative currents in the “no-drag frame” as polynomials in temperature and chemical potential with known anomaly coefficients. These general results are illustrated and confirmed by a calculation in the chiral kinetic theory and in the quark-gluon plasma at high temperature.

We identify a new, flux-dependent correction to the antineutrino spectrum as produced in nuclear reactors. The abundance of certain nuclides, whose decay chains produce antineutrinos above the threshold for inverse beta decay, has a nonlinear dependence on the neutron flux, unlike the vast majority of antineutrino producing nuclides, whose decay rate is directly related to the fission rate. We have identified four of these so-called nonlinear nuclides and determined that they result in an antineutrino excess at low energies below 3.2 MeV, dependent on the reactor thermal neutron flux. We develop an analytic model for the size of the correction and compare it to the results of detailed reactor simulations for various real existing reactors, spanning 3 orders of magnitude in neutron flux. In a typical pressurized water reactor the resulting correction can reach $\sim 0.9\%$ of the low energy flux which is comparable in size to other, known low-energy corrections from spent nuclear fuel and the nonequilibrium correction. For naval reactors the nonlinear correction may reach the 5% level by the end of cycle.

We report on ab initio no-core shell model calculations of the mirror $\mathrm{\Lambda }$ hypernuclei ${}_{\mathrm{\Lambda }}{}^4\mathrm{H}$ and ${}_{\mathrm{\Lambda }}{}^4\mathrm{He}$, using the Bonn-Jülich leading-order chiral effective field theory hyperon-nucleon potentials plus a charge symmetry breaking $\mathrm{\Lambda }-{\mathrm{\Sigma }}^0$ mixing vertex. In addition to reproducing rather well the $0_{\mathrm{g}.\mathrm{s}.}^{+}$ and $1_{\mathrm{exc}}^{+}$ binding energies, these four-body calculations demonstrate for the first time that the observed charge symmetry breaking splitting of mirror levels, reaching hundreds of keV for $0_{\mathrm{g}.\mathrm{s}.}^{+}$, can be reproduced using realistic theoretical interaction models, although with a non-negligible momentum cutoff dependence. Our results are discussed in relation to recent measurements of the ${}_{\mathrm{\Lambda }}{}^4\mathrm{H}(0_{\mathrm{g}.\mathrm{s}.}^{+})$ binding energy at the Mainz Microtron [A. Esser et al. (A1 Collaboration), Phys. Rev. Lett. 114, 232501 (2015)] and the ${}_{\mathrm{\Lambda }}{}^4\mathrm{He}(1_{\mathrm{exc}}^{+})$ excitation energy [T.O. Yamamoto et al. (J-PARC E13 Collaboration), Phys. Rev. Lett. 115, 222501 (2015)].