We present a new experimental method to correlate the isotopic composition of intermediate mass fragments (IMF) emitted at midrapidity in semiperipheral collisions with the emission timescale: IMFs emitted in the early stage of the reaction show larger values of $\langle N/Z\rangle$ isospin asymmetry, stronger angular anisotropies, and reduced odd-even staggering effects in neutron to proton ratio $\langle N/Z\rangle$ distributions than those produced in sequential statistical emission. All these effects support the concept of isospin “migration”, that is sensitive to the density gradient between participant and quasispectator nuclear matter, in the so called neck fragmentation mechanism. By comparing the data to a stochastic mean field (SMF) simulation we show that this method gives valuable constraints on the symmetry energy term of nuclear equation of state at subsaturation densities. An indication emerges for a linear density dependence of the symmetry energy.

A complete set of existing data on hot fusion reactions leading to synthesis of superheavy nuclei of $Z=114–118$, obtained in a series of experiments in Dubna and later in GSI Darmstadt and LBNL Berkeley, was analyzed in terms of an angular-momentum-dependent version of the fusion-by-diffusion (FBD) model with fission barriers and ground-state masses taken from the Warsaw macroscopic-microscopic model (involving nonaxial shapes) of Kowal et al. The only empirically adjustable parameter of the model, the injection-point distance ($s_{\mathrm{inj}}$), has been determined individually for all the reactions. Very regular systematics of this parameter have been established. The regularity of the obtained $s_{\mathrm{inj}}$ systematics indirectly points at the internal consistency of the whole set of fission barriers used in the calculations. (In an attempt to fit the same set of data by using the alternative theoretical fission barriers of Möller et al. we did not obtain such a consistent result.) Having fitted all the experimental excitation functions for elements $Z=114$–118, the FBD model was used to predict cross sections for synthesis of elements $Z=119$ and 120. Regarding prospects to produce the new element $Z=119$, our calculations prefer the ${}^{252}$Es(${}^{48}$Ca,xn)${}^{300-x}$119 reaction, for which the synthesis cross section of about 0.2 pb in $4n$ channel at $E_{\mathrm{c}.\mathrm{m}.}\approx 220$ MeV is expected. The most favorable reaction to synthesize the element $Z$ $=$ 120 turns out to be ${}^{249}$Cf(${}^{50}$Ti,xn)${}^{299-x}$120, but the predicted cross section for this reaction is only 6 fb (for $3n$ and $4n$ channels).

The prescission neutron multiplicity excitation function is measured for the first time for three isotopes across a major closed shell in order to investigate the shell effects on fission hindrance. Three isotopes of Fr (${}^{213,215,217}$Fr) are populated by fusion of ${}^{19}\mathrm{F}{+}^{194,196,198}$Pt in the excitation energy range of 46.6–91.8 MeV. While ${}^{213}$Fr has a major neutron shell closure at $N=126$, ${}^{215}$Fr and ${}^{217}$Fr are away from the closed shell. It is found from the statistical model analysis of the experimental data that the strengths of nuclear dissipation for nuclei away from shell closure are very similar. On the other hand, the dissipation is relatively weaker for a shell-closed nucleus in comparison to adjacent nuclei away from shell closure.

Applying a quark combination model for the hadronization of quark gluon plasma (QGP) and a relativistic transport (ART) model for the subsequent hadronic rescattering process, we investigate the production of $K^{*0}$ and ${\Sigma }^{*}$ resonances in central Au+Au collisions at $\sqrt{s_{NN}}=$ 200 and 62.4 GeV. The initial $K^{*0}$ produced via hadronization is higher than the experimental data in the low-$p_T$ region and is close to the data at 2–3 GeV/$c$. We take into account the hadronic rescattering effects which lead to a strong suppression of $K^{*0}$ with low $p_T$ and find that the $p_T$ spectrum of $K^{*0}$ can be well described. The time span of the hadronic rescattering stage is estimated according to the suppressed magnitude of $K^{*0}$ yield. The $p_T$ spectrum of ${\Sigma }^{*}$ directly obtained by quark combination hadronization in central Au+Au collisions at 200 GeV is in agreement with the experimental data, which shows a weak hadronic rescattering effects. The elliptic flow $v_2$ of ${\Sigma }^{*}$ in minimum-bias Au+Au collisions at 200 GeV and a $p_T$ spectrum of ${\Sigma }^{*}$ at lower 62.4 GeV are predicted.

By using resonance model, we investigate $K^{+}N\to KN\eta$ reactions with the assumption that these reactions are dominated by the excitation of $N^{*}\left(1535\right)$ near threshold. It is found that the hyperon and $\rho$ exchange diagrams give the most important contributions to these reactions. Thus, these reactions may be a good place to study the coupling of $N^{*}\left(1535\right)$ with $K\Lambda$, $K\Sigma$, and $N\rho$ channels. We demonstrate that the angular distributions of final particles provide useful information about the different mechanisms of the $N^{*}\left(1535\right)$ excitations, which could be useful for future experimental analysis on these reactions.

We report an extraction of nucleon resonance couplings using ${\pi }^{-}$ photoproduction cross sections on the neutron. The world database for the process $\gamma n\to {\pi }^{-}p$ above 1 GeV has quadrupled with the addition of differential cross sections from the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab in Hall B. Differential cross sections from CLAS have been improved with a final-state interaction determination using a diagrammatic technique taking into account the $NN$ and $\pi N$ final-state interaction amplitudes. Resonance couplings have been extracted and compared to previous determinations. With the addition of these cross sections  significant changes are seen in the high-energy behavior of the Scattering Analysis Interactive Dial-in program cross sections and amplitudes.

Excited states in ${}^{18}$C were populated by the one-proton knockout reaction of an intermediate energy radioactive ${}^{19}$N beam. The lifetime of the first $2^{+}$ state was measured with the Köln/NSCL plunger via the recoil distance method to be $\tau \left(2_1^{+}\right)=22.4\pm 0.9{\left(\mathrm{stat}\right)}_{-2.2}^{+3.3}\left(\mathrm{syst}\right)$ ps, which corresponds to a reduced quadrupole transition strength of $B(E2;2_1^{+}\to 0_1^{+})=3.{64}_{-0.14}^{+0.15}{\left(\mathrm{stat}\right)}_{-0.47}^{+0.40}\left(\mathrm{syst}\right)$ e${}^2$fm${}^4$. In addition, an upper limit on the lifetime of a higher-lying state feeding the $2_1^{+}$ state was measured to be $\tau <4.6$ ps. The results are compared to large-scale ab initio no-core shell model calculations using two accurate nucleon-nucleon interactions and the importance-truncation scheme. The comparison provides strong evidence that the inclusion of three-body forces is needed to describe the low-lying excited-state properties of this $A=18$ system.

$\beta$-delayed proton emission from nuclides in the neighborhood of ${}^{100}$Sn was studied at the National Superconducting Cyclotron Laboratory (NSCL). The nuclei were produced by fragmentation of a 120 MeV/nucleon ${}^{112}$Sn primary beam on a Be target. Beam purification was provided by the A1900 Fragment Separator and the Radio Frequency Fragment Separator. The fragments of interest were identified and their decay was studied with the NSCL Beta Counting System in conjunction with the Segmented Germanium Array. The nuclei ${}^{96}$Cd, ${}^{98}$In${}^g$, ${}^{98}$In${}^m$, and ${}^{99}$In were identified as $\beta$-delayed proton emitters, with branching ratios $b_{\beta p}=5.5\left(40\right)\%$, 5.5${}_{-2}^{+3}$%, 19(2)%, and 0.9(4)%, respectively. The branching ratios for ${}^{89}$Ru, ${}^{91,92}$Rh, ${}^{93}$Pd, and ${}^{95}$Ag were deduced for the first time with $b_{\beta p}=3_{-1.7}^{+1.9}\%$, 1.3(5)%, 1.9(1)%, 7.5(5)%, and 2.5(3)%, respectively. The $b_{\beta p}=22\left(1\right)\%$ value for ${}^{101}$Sn was deduced with higher precision than previously reported. The impact of the newly measured $b_{\beta p}$ values on the composition of the type I x-ray burst ashes was studied.

The motion of $l=0$ antibound poles of the $S$ matrix with varying potential strength is calculated in a cut-off Woods-Saxon (WS) potential and in a potential that goes to zero smoothly at a finite distance and is exactly zero beyond [P. Salamon and T. Vertse, Phys. Rev. C 77, 037302 (2008)]. The pole positions of the antibound states as well as of the resonances depend on the cutoff radius, especially for higher node numbers. The starting points (at potential zero) of the pole trajectories correlate well with the range of the potential. The normalized antibound radial wave functions on the imaginary $k$ axis below and above the coalescence point have been found to be real and imaginary, respectively.

Background: Nuclear effects can have a significant impact on neutrino-nucleus interactions. In particular, data from neutrino experiments with broad energy distributions require complex theoretical models that are able to take all the relevant channels into account as well as incorporate nuclear effects in both initial and final-state interactions.

Purpose: We investigate neutrino and antineutrino scattering on iron and carbon in the energy range from 1 to 50 GeV, which is relevant to current and coming experiments (MINOS, NO$\nu$A, and Miner$\nu$a).

Method: The Giessen Boltzmann-Uehling-Uhlenbeck (GiBUU) model, which implements all reaction channels relevant for neutrino energies under consideration, is used for an investigation of neutrino-nucleus reactions.

Results: Our calculations are compared with the recent NOMAD and MINOS data for the integrated inclusive cross sections. Predictions are made for the differential cross sections for semi-inclusive final states (pions, kaons, and nucleons) for the MINOS and NO$\nu$A fluxes.

Conclusions: Nuclear effects in the initial-state interactions may slightly change the inclusive nuclear cross section as compared to the free nucleon ones. Final-state interactions noticeably change the spectra of the outgoing hadrons. In the Miner$\nu$a and NO$\nu$A experiments these effects should be visible in the kinetic energy distributions of the final pions, kaons, and nucleons. Secondary interactions play an important role for strangeness production. They make it very difficult to extract the neutrino-induced strangeness production cross section in experiments using nuclear targets.

Equilibrium positions of the ${}^7$Be atom both inside and outside the C${}_{36}$ fullerene are found and the electron density at the ${}^7$Be nucleus, $\rho \left(0\right)$, for these positions are calculated using a high-accuracy ab initio post-Hartree-Fock method. If ${}^7$Be is located outside the C${}_{36}$ cage the electron density at the ${}^7$Be nucleus practically coincides with $\rho \left(0\right)$ of a single ${}^7$Be atom. In the encapsulated ${}^7$Be@C${}_{36}$ case $\rho \left(0\right)$ is found to lie close to the electron density $\rho \left(0\right)$ of the ${}^7$Be${}^{2+}$ ion with the unoccupied 2$s$ electron shell, which results in the smallest value among all known ${}^7$Be-based compounds where the influence of chemical environment on the probability of electron capture by ${}^7$Be has been investigated. Consequently, the ${}^7$Be half-life in the ${}^7$Be@C${}_{36}$ molecular complex is expected to be the largest.

We present STAR measurements of azimuthal anisotropy by means of the two- and four-particle cumulants $v_2$ ($v_2\left\{2\right\}$ and $v_2\left\{4\right\}$) for Au+Au and Cu+Cu collisions at center-of-mass energies $\sqrt{s_{{}_{NN}}}=62.4$ and 200 GeV. The difference between $v_2{\left\{2\right\}}^2$ and $v_2{\left\{4\right\}}^2$ is related to $v_2$ fluctuations (${\sigma }_{v_2}$) and nonflow $\left({\delta }_2\right)$. We present an upper limit to ${\sigma }_{v_2}/v_2$. Following the assumption that eccentricity fluctuations ${\sigma }_{\varepsilon }$ dominate $v_2$ fluctuations $\frac{{\sigma }_{v_2}}{v_2}\approx \frac{{\sigma }_{\varepsilon }}{\varepsilon }$ we deduce the nonflow implied for several models of eccentricity fluctuations that would be required for consistency with $v_2\left\{2\right\}$ and $v_2\left\{4\right\}$. We also present results on the ratio of $v_2$ to eccentricity.

Heavy nuclei at collider energies are a source of high-energy Weizsäcker-Williams photons. This photon flux may be utilized to study high-energy photon-nucleus interactions. Here we concentrate on the coherent diffractive production of heavy vector mesons on nuclear targets and show how it probes the unintegrated glue of the nucleus in the saturation domain. We present predictions for rapidity distributions of exclusive coherent $J/\Psi$ and ${\rm Y}$ mesons which can be measured by the ALICE experiment at the Large Hadron Collider.

We consider the transition (${\gamma }^{*}{\pi }^0(\eta ,{\eta }^{\prime })\to \gamma$) and electromagnetic (${\gamma }^{*}{\pi }^{\pm }\to {\pi }^{\pm }$) form factors in a wide range of energy-momentum transfer $s$. We employ dispersion relations to connect the timelike and spacelike regions. We discuss the role of resonances and QCD partonic contributions. We find that the former give sizable contributions in the currently available range of $s$ and for the latter we consider the role of Reggeized fermion exchange.

We theoretically investigate the elastic scattering of 50-MeV ${\Sigma }^{-}$ hyperons from ${}^{28}$Si and ${}^{208}$Pb in order to clarify the radial distribution of $\Sigma$-nucleus (optical) potentials. The angular distributions of differential cross sections are calculated using several potentials that can explain experimental data of the ${\Sigma }^{-}$ atomic x-ray and (${\pi }^{-}$, $K^{+}$) reaction spectra simultaneously. The magnitude and oscillation pattern of the angular distributions are understood by the use of nearside/farside decompositions of their scattering amplitudes. It is shown that the resultant angular distributions provide a clue to discriminating among the radial distributions of the potentials that have a repulsion inside the nuclear surface and an attraction outside the nucleus with a sizable absorption.

We calculate diffusion and hadronization of heavy quarks in high-energy heavy-ion collisions, implementing the notion of a strongly coupled quark-gluon plasma in both micro- and macroscopic components. The diffusion process is simulated using relativistic Fokker-Planck dynamics for elastic scattering in a hydrodynamic background. The heavy-quark transport coefficients in the medium are obtained from nonperturbative $T$-matrix interactions which build up resonant correlations close to the transition temperature. The latter also form the basis for hadronization of heavy quarks into heavy-flavor mesons via recombination with light quarks from the medium. The pertinent resonance recombination satisfies energy conservation and provides an equilibrium mapping between quark and meson distributions. The recombination probability is derived from the resonant heavy-quark scattering rate. Recombination is found to dominate at low transverse momentum ($p_T$) and to yield to fragmentation at high $p_T$. Our approach emphasizes the role of resonance correlations in the diffusion and hadronization processes. Calculations of the nuclear modification factor and elliptic flow of $D$ and $B$ mesons and their decay electrons in Au-Au collisions at the Relativistic Heavy Ion Collider indicate the importance of a realistic medium flow in a quantitative interpretation of heavy-flavor data.

A relativistically invariant quantum theory first advanced by Bakamjian and Thomas has proven very useful in modeling few-body systems. For three particles or more, this approach is known formally to fail the constraint of cluster separability, whereby symmetries and conservation laws that hold for a system of particles also hold for isolated subsystems. Cluster separability can be restored by means of a recursive construction using unitary transformations, but implementation is difficult in practice, and the quantitative extent to which the Bakamjian-Thomas approach violates cluster separability has never been tested. This paper provides such a test by means of a model of a scalar probe in a three-particle system for which (1) it is simple enough that there is a straightforward solution that satisfies Poincaré invariance and cluster separability and (2) one can also apply the Bakamjian-Thomas approach. The difference between these calculations provides a measure of the size of the corrections from the Sokolov construction that are needed to restore cluster properties. Our estimates suggest that, in models based on nucleon degrees of freedom, the corrections that restore cluster properties are too small to affect calculations of observables.

Recent self-consistent mean-field calculations predict a substantial depletion of the proton density in the interior of ${}^{34}\text{Si}$. In the present study, we investigate how correlations beyond the mean field modify this finding. The framework of the calculation is a particle-number and angular-momentum projected generator coordinate method based on Hartree-Fock-Bogoliubov+Lipkin-Nogami states with axial quadrupole deformation. The parametrization SLy4 of the Skyrme energy density functional is used together with a density-dependent pairing energy functional. For the first time, the generator coordinate method is applied to the calculation of charge densities. The impact of pairing correlations, symmetry restorations and shape mixing on the density profile is analyzed step by step. All these effects significantly alter the radial density profile, and tend to bring it closer to a Fermi-type density distribution.

The hyperfine structure of 276.9-nm atomic transition has been studied by the resonant ionization spectroscopy method at mass-separator IRIS (Investigation of Radioactive Isotopes on Synchrocyclotron), Petersburg Nuclear Physics Institute (PNPI) for the odd Tl isomers with $I$ = 9/2 and $A$ = 187–197. A differential hyperfine structure anomaly for $6p{}^2{P}_{1/2}$ and $7s{}^2{S}_{1/2}$atomic states in Tl isomers with $I$ = 9/2 has been determined. It is described by the recently developed theoretical approach fairly well. This enables one to recalculate the magnetic moments of ${}^{187-193}$Tl${}^m$ ($I$ = 9/2) from previously measured hyperfine splittings for $7s{}^2{S}_{1/2}$ states and to determine for the first time the magnetic moments for ${}^{197}$Tl${}^m$ and ${}^{195}$Tl${}^m$ ($I$ = 9/2) from hyperfine splittings for $6p{}^2{P}_{1/2}$ states with properly taking into account the rather great hyperfine structure anomaly. Similar measurements with greater accuracy have been proposed for the other nuclear states in odd-odd Tl isotopes. These measurements could shed light on the nuclear magnetization distribution in these isotopes.