Background: The neutrino-nucleus ($\nu A$) cross section is a major source of systematic uncertainty in neutrino-oscillation studies. A precise $\nu A$ scattering model, in which multinucleon effects are incorporated, is pivotal for an accurate interpretation of the data.

Purpose: In $\nu A$ interactions, meson-exchange currents (MECs) can induce two-nucleon ($2N$) knockout from the target nucleus, resulting in a two-particle two-hole (2p2h) final state. They also affect single nucleon ($1N$) knockout reactions, yielding a one-particle one-hole (1p1h) final state. Both channels affect the inclusive strength. We present a study of axial and vector, seagull and pion-in-flight currents in muon-neutrino induced $1N$ and $2N$ knockout reactions on ${}^{12}C$.

Method: Bound and emitted nucleons are described as Hartree-Fock wave functions. For the vector MECs, the standard expressions are used. For the axial current, three parametrizations are considered. The framework developed here allows for a treatment of MECs and short-range correlations (SRCs).

Results: Results are compared with electron-scattering data and with literature. The strengths of the seagull, pion-in-flight, and axial currents are studied separately and double differential cross sections including MECs are compared with results including SRCs. A comparison with MiniBooNE and T2K data is presented.

Conclusions: In the 1p1h channel, the effects of the MECs tend to cancel each other, resulting in a small effect on the double differential cross section. $2N$ knockout processes provide a small contribution to the inclusive double differential cross section, ranging from the $2N$ knockout threshold into the dip region. A fair agreement with the MiniBooNE and T2K data is reached.

The fusion excitation functions of ${}^{249-263}\mathrm{No}$ are studied by using various reaction systems based on the dinuclear system model. The neutron-rich radioactive beam ${}^{22}\mathrm{O}$ is used to produce neutron-rich nobelium isotopes, and the new neutron-rich isotopes ${}^{261-263}\mathrm{No}$ are synthesized by ${}^{242}\mathrm{Pu}({}^{22}\mathrm{O},3n){}^{261}\mathrm{No}, {}^{244}\mathrm{Pu}({}^{22}\mathrm{O},4n){}^{262}\mathrm{No}$, and ${}^{244}\mathrm{Pu}({}^{22}\mathrm{O},3n){}^{263}\mathrm{No}$ reactions, respectively. The corresponding maximum evaporation residue cross sections are 0.628, 4.649, and 1.638 $\mu \mathrm{b}$, respectively. The effects of the three processes (capture, fusion, and survival) in the complete fusion reaction are also analyzed. From investigation, a neutron-rich radioactive beam as the projectile and neutron-rich actinide as the target could be a new selection of the projectile-target combination to produce a neutron-rich heavy nuclide.

The production mechanisms of open strangeness ($K^{*}$) and open charm ($D^{*}$) vector mesons in ${\pi }^{-}p$ scattering, namely, ${\pi }^{-}+p\to K^{*0}+\mathrm{\Lambda }$ and ${\pi }^{-}+p\to D^{*-}+{\mathrm{\Lambda }}_c^{+}$, are investigated within the modified quark-gluon string model. To identify the major reaction mechanisms, we consider the subsequent decays of the produced vector mesons into two pseudoscalar mesons, i.e., $K^{*}\to K+\pi$ and $D^{*}\to D+\pi$. We found that the decay distributions and density matrix elements are sensitive to the production mechanisms and can be used to disentangle the vector trajectory and pseudoscalar trajectory exchange models. Our results for $K^{*}$ production are compared with the currently available experimental data and the predictions for $D^{*}$ production process are presented as well. Our predictions can be tested at the present or planned experimental facilities.

The ${}^8\mathrm{Li}(\alpha ,n){}^{11}\mathrm{B}$ reaction is regarded as the key reaction in the inhomogeneous big bang and in type-II supernova nucleosynthesis. Recently, the importance of this reaction to solving the ${}^7\mathrm{Li}$ problem, i.e., the inconsistency between the predicted and the observed primordial ${}^7\mathrm{Li}$ abundances, has also been noted. The most recent cross-section data published by our collaboration group in 2006 [H. Ishiyama et al., Phys. Lett. B 640, 82 (2006)] cover the 0.7- to 2.6-MeV energy region in the center-of-mass system. Here, we present additional data spanning the 0.45- to 1.8-MeV energy region. Thus, the predominant energy region for the big bang nucleosynthesis, corresponding to $T_9=1$ (where $T_9$ is a temperature unit equivalent to ${10}^9$ K), is almost completely spanned by the previous [H. Ishiyama et al., Phys. Lett. B 640, 82 (2006)] and present results together.

Different families of geometric shapes, derived mainly from lemniscatoids, are proposed to describe ground and excited states of leptodermous distributions of nuclear matter. The transition from one spherical or ellipsoidal nucleus to several spherical or ellipsoidal nuclei or vice versa (in the decay and entrance channels of nuclear reactions: fission, fusion, and fragmentation) is particularly investigated. The geometric characteristics of these configurations are given, allowing calculations of the system energy, dynamics of the reactions, and angular distribution of the fragments.

In this paper we discuss the relation of particle number cumulants and correlation functions. It is argued that measuring couplings of the genuine multiparticle correlation functions could provide cleaner information on possible nontrivial dynamics in heavy-ion collisions. We extract integrated multiproton correlation functions from the presently available experimental data on proton cumulants. We find that the STAR data contain significant four-proton correlations, at least at the lower energies, with indication of changing dynamics in central collisions. We also find that these correlations are rather long ranged in rapidity. Finally, using the Ising model, we demonstrate how the signs of the multiproton correlation functions may be used to exclude certain regions of the phase diagram close to the critical point.

Background: The inconsistency in the results obtained from the Rosenbluth separation method and the high-$Q^2$ recoil polarization results on the ratio ${\mu }_p{G}_E^p/G_M^p$ implies a systematic difference between the two techniques. Several studies suggest that missing higher-order radiative corrections to elastic electron-proton scattering cross section ${\sigma }_R(\varepsilon ,Q^2)$ and in particular hard two-photon-exchange (TPE) contributions could account for the discrepancy.

Purpose: In this work, I improve on and extend to low and high $Q^2$ values the extractions of the $\varepsilon$ dependence of the real parts of the TPE amplitudes relative to the magnetic form factor, as well as the ratio $P_l/P_l^{\text{Born}}(\varepsilon ,Q^2)$ by using world data on ${\sigma }_R(\varepsilon ,Q^2)$ with an emphasis on precise new data covering the low-momentum region which is sensitive to the large-scale structure of the nucleon.

Method: I combine cross section and polarization measurements of elastic electron-proton scattering to extract the TPE amplitudes. Because the recoil polarization data were confirmed “experimentally” to be essentially independent of $\varepsilon$, I constrain the ratio $P_t/P_l(\varepsilon ,Q^2)$ to its $\varepsilon$-independent term (Born value) by setting the TPE contributions to zero. This allows for the amplitude $Y_M(\varepsilon ,Q^2)$ and ${\sigma }_R(\varepsilon ,Q^2)$ to be expressed in terms of the remaining two amplitudes $Y_E(\varepsilon ,Q^2)$ and $Y_3(\varepsilon ,Q^2)$ which in turn are parametrized as second-order polynomials in $\varepsilon$ and $Q^2$ to reserve as possible the linearity of ${\sigma }_R(\varepsilon ,Q^2)$ as well as to account for possible nonlinearities in the TPE amplitudes. Furthermore, I impose the Regge limit which ensures the vanishing of the TPE contributions to ${\sigma }_R(\varepsilon ,Q^2)$ and the TPE amplitudes in the limit $\varepsilon \to 1$.

Results: I provide simple parametrizations of the TPE amplitudes, along with an estimate of the fit uncertainties. The extracted TPE amplitudes are compared with previous phenomenological extractions and TPE calculations. The $P_l/P_l^{\text{Born}}$ ratio is extracted by using the new parametrizations of the TPE amplitudes and compared to previous extractions, TPE calculations, and direct measurements at $Q^2{=2.50(\mathrm{GeV}/c)}^2$.

Conclusions: The extracted TPE amplitudes are on the few-percentage-points level and behave roughly linearly with increasing $Q^2$ where they become nonlinear at high $Q^2$. Contrary to $Y_M$, which is influenced mainly by elastic contributions, I find $Y_E$ to be influenced by inelastic contributions at large $Q^2$ values. While $Y_E$ and $Y_3$ differ in magnitude, they have opposite sign and tend to partially cancel each other. This suggests that the TPE correction to ${\sigma }_R(\varepsilon ,Q^2)$ is driven mainly by $Y_M$ and to a lesser extent by $Y_3$ in agreement with previous phenomenological extractions and hadronic TPE calculations.

We investigate the effect of resonance decays on the three-particle correlator charge separation observable in a search for the chiral magnetic effect, using a simple simulation with realistic inputs. We find that resonance decays can largely account for the measured signal. We suppress the elliptic flow ($v_2$) background by using zero event-by-event $v_2$ (or via the mixed-event technique). We find that the background is suppressed, but not eliminated as naively anticipated. We identify the reason to be the nonidenticalness of the resonance and final-state particle's $v_2$ and the induced correlation between the transverse momentum dependent resonance $v_2$ and decay angle. We make predictions for the charge separation signal due to resonance decays in 200 GeV Au+Au collisions.

Using the ${}^{168}\mathrm{Er}({}^{10}\mathrm{B},5n)$ reaction at a beam energy of 68 MeV, new data have been obtained for the population and decay of a $T_{1/2}=148$ ns, $K^{\pi }=21/2^{-}$ three-quasiparticle isomer at 1717 keV in ${}^{173}\mathrm{Ta}$. Revised decay energies and intensities have been determined, together with newly observed members of a rotational band associated with the isomer. By comparison with other isomers in the $A\approx 180$ deformed region, the ${}^{173}\mathrm{Ta}$ isomer properties help to specify the key degrees of freedom that determine $K$-forbidden transition rates. In particular, when all three quasiparticles are of the same nucleon type, there is a strong dependence of the $E2$ reduced hindrance factor on the isomer excitation energy.

The elastic scattering of the radioactive nucleus ${}^7\mathrm{Be}$ from a ${}^{28}\mathrm{Si}$ target was studied at four near-barrier energies: 13.2, 17.2, 19.8, and 22.0 MeV ($E/V_C=1.14$, 1.48, 1.71, and 1.90). Angular distribution measurements were performed at each energy with the multidetector array EXPADES in conjunction with two Parallel-Plate Avalanche Counters (PPAC) to enable beam ray reconstruction of the events. The data are analyzed in a double-folding framework and the energy evolution of the optical potential as well as the total reaction cross sections are deduced and discussed.

We study the net-charge fluctuation $D$-measure variable, in high-energy heavy-ion collisions in heavy-ion jet interaction generator (HIJING), ultrarelativistic quantum molecular dynamics (UrQMD), and hadron resonance gas (HRG) models for various center-of-mass energies ($\sqrt{s_{{}_{NN}}}$). The effects of kinematic acceptance and resonance decay, in the pseudorapidity acceptance interval ($\mathrm{\Delta }\eta$) and lower transverse momentum ($p_T^{\text{min}}$) threshold, on fluctuation measures are discussed. A strong dependence of $D$ with the $\mathrm{\Delta }\eta$ in HIJING and UrQMD models is observed as opposed to results obtained from the HRG model. The dissipation of fluctuation signal is estimated by fitting the $D$ measure as a function of the $\mathrm{\Delta }\eta$. An extrapolated function for higher $\mathrm{\Delta }\eta$ values at lower $\sqrt{s_{{}_{NN}}}$ is different from the results obtained from models. Particle species dependence of $D$ and the effect of the $p_T^{\text{min}}$ selection threshold are discussed in HIJING and HRG models. The comparison of $D$, at midrapidity, of net-charge fluctuations at various $\sqrt{s_{{}_{NN}}}$ obtained from the models with the data from the A Large Ion Collider Experiment (ALICE) experiment is discussed. The results from the present paper as a function of $\mathrm{\Delta }\eta$ and $\sqrt{s_{{}_{NN}}}$ will provide a baseline for comparison to experimental measurements.

Complex and exotic nuclear geometries, collectively referred to as “nuclear pasta,” are expected to appear naturally in dense nuclear matter found in the crusts of neutron stars and supernovae environments. The pasta geometries depend on the average baryon density, proton fraction, and temperature and are critically important in the determination of many transport properties of matter in supernovae and the crusts of neutron stars. Using a set of self-consistent microscopic nuclear energy density functionals, we present the first results of large scale quantum simulations of pasta phases at baryon densities $0.03\le \rho \le 0.10{\mathrm{fm}}^{-3}$, proton fractions $0.05\le Y_p\le 0.40$, and zero temperature. The full quantum simulations, in particular, allow us to thoroughly investigate the role and impact of the nuclear symmetry energy on pasta configurations. We use the Sky3D code that solves the Skyrme Hartree-Fock equations on a three-dimensional Cartesian grid. For the nuclear interaction we use the state-of-the-art UNEDF1 parametrization, which was introduced to study largely deformed nuclei, hence is suitable for studies of the nuclear pasta. Density dependence of the nuclear symmetry energy is simulated by tuning two purely isovector observables that are insensitive to the current available experimental data. We find that a minimum total number of nucleons $A=2000$ is necessary to prevent the results from containing spurious shell effects and to minimize finite size effects. We find that a variety of nuclear pasta geometries are present in the neutron star crust, and the result strongly depends on the nuclear symmetry energy. The impact of the nuclear symmetry energy is less pronounced as the proton fractions increase. Quantum nuclear pasta calculations at $T=0$ MeV are shown to get easily trapped in metastable states, and possible remedies to avoid metastable solutions are discussed.

We analyze the power counting of the peripheral singlet partial waves in nucleon-nucleon scattering. In agreement with conventional wisdom, we find that pion exchanges are perturbative in the peripheral singlets. We quantify from the effective field theory perspective the well-known suppression induced by the centrifugal barrier in the pion-exchange interactions. By exploring perturbation theory up to fourth order, we find that the one-pion-exchange potential in these channels is demoted from leading to subleading order by a given power of the expansion parameter that grows with the orbital angular momentum. We discuss the implications of these demotions for few-body calculations: though higher partial waves have been known for a long time to be irrelevant in these calculations (and are hence ignored), here we explain how to systematize the procedure in a way that is compatible with the effective field theory expansion.

We are testing the applicability of the algebraic procedure developed by Richardson for bound states to solve the pairing-force problem in presence of states with complex energies. This scenario, in which nucleons occupy single-particle states with complex energies and interact via the pairing force, is closely related to the microscopic description of nuclei with a large neutron (or proton) excess in basis which includes single-particle resonances. It is shown that the method gives results which are in good agreement with exact solutions. This finding is in coincidence with previously published works, by other authors, based on different methods to describe resonances.

The majority of partial and total photoneutron cross-section data were obtained using beams of quasimonoenergetic photons produced by annihilation in the flight of fast positrons and the method of neutron multiplicity-sorting procedures at Lawrence Livermore National Laboratory (California) and Saclay (France). Significant systematic disagreements between the two sets of data were obtained by employing the new objective physical data reliability criteria. It was found that many reaction cross sections are not reliable. As an example, a significant systematic uncertainty of the ${}^{159}\mathrm{Tb}$($\gamma ,2n$) cross-section data measured at Livermore is presented. The ($\gamma ,2n$) reaction cross section was obtained as erroneous, whereas the ($\gamma ,3n$) reaction cross section was not obtained at all. The detailed discussion of this analysis is presented. The newly unmeasured before ($\gamma ,3n$) cross section is obtained from the experimental ($\gamma ,2n$) cross section using simple equations based on the physical criteria.

The time-dependent generator coordinate method with the gaussian overlap approximation (TDGCM+GOA) formalism is applied to describe the fission of ${}^{252}\mathrm{Cf}$. We perform analysis of fission from the initial states laying in the energetic range from the ground state to the state located 4 MeV above the fission barrier. The fission fragment mass distributions, obtained for different parity, energy of levels, and types of mixed states, are calculated and compared with experimental data. The impact of the total time of wave packet propagation on the final results is studied as well. The weak dependence of obtained mass yields on the initial conditions is shown.

A combined analysis of the reactions ${\pi }^{+}p\to {\pi }^{+}p, {\pi }^{-}p\to {\pi }^{-}p$, and ${\pi }^{-}p\to {\pi }^{0}n$ is carried out with a chiral quark model. The observations are reasonably described from the $\mathrm{\Delta }\left(1232\right)$ resonance region up to the $N\left(1440\right)$ resonance region. Besides the $\mathrm{\Delta }\left(1232\right)P_{33}$, a confirmed role of $N\left(1440\right)P_{11}$ is found in the polarizations of the ${\pi }^{-}p\to {\pi }^{-}p$ and ${\pi }^{-}p\to {\pi }^{0}n$ reactions. It is found that the $N\left(1440\right)N\pi$ and $\mathrm{\Delta }\left(1232\right)N\pi$ couplings are about 1.7 and 4.8 times larger than the expectations from the simple quark model, respectively, which may suggest the unusual property of $N\left(1440\right)P_{11}$ and deficiency of the simple quark model in the description of $N\left(1440\right)P_{11}$ and $\mathrm{\Delta }\left(1232\right)P_{33}$. The $t$- and $u$-channel backgrounds have notable contributions to the ${\pi }^{+}p\to {\pi }^{+}p$ reaction, while in the ${\pi }^{-}p\to {\pi }^{-}p,{\pi }^{0}n$ reactions, the $s$-channel nucleon and $t$- and $u$-channel backgrounds play crucial roles.