Background: Deuteron-induced one-neutron transfer reactions have been used to extract single-particle properties of nuclei, and the adiabatic (AD) approximation is often used to simply treat the deuteron breakup states.

Purpose: The primary goal is to examine the validity of the AD approximation for the $(d,p)$ reaction systematically. We clarify also the role of the closed channels often ignored in the description of breakup reactions.

Methods: We calculate the $(d,p)$ cross sections with the continuum-discretized coupled-channels method (CDCC) for 128 reaction systems and compare the results with those obtained by the CDCC calculation with the AD approximation. Effect of the closed channels are investigated by ignoring them in CDCC.

Results: The AD approximation affects in general the $(d,p)$ cross section by less than 20%, but some exceptional (nonadiabatic) cases for which the AD approximation breaks down are found. The closed channels turn out to have significant effects on the cross section at deuteron energies less than about 10 MeV.

Conclusions: The use of the AD approximation in the description of the $(d,p)$ reaction can be justified in many cases, with the uncertainty of less than about 20%. The existence of some nonadiabatic cases nevertheless should be realized. The neglect of the closed channels without confirming the convergence of the CDCC result is not recommended.

Correlations born before the onset of hydrodynamic flow can leave observable traces on the final-state particles. Measurement of these correlations yield important information on the isotropization and thermalization processes. Starting from a Boltzmann-like kinetic theory in the presence of dynamic Langevin noise, we derive a new partial differential equation for the two-particle correlation function that respects the microscopic conservation laws. To illustrate how these equations can be used, we study the effect of thermalization on long-range correlations. We show quite generally that two-particle correlations at early times depend on $S$, the average probability that a parton suffers no interactions. We extract $S$ from transverse momentum fluctuations measured in nucleus-nucleus collisions and predict the degree of partial thermalization in proton-nucleus experiments.

The hadronic phase in ultrarelativistic nuclear collisions has a large influence on final state observables like multiplicity, flow, and $p_t$ spectra, as studied in the UrQMD approach. In this model one assumes that a nonequilibrium decoupling phase follows a fluid dynamical description of the high density phase. Hadrons are produced assuming local thermal equilibrium and dynamically decouple during the hadronic rescattering until the particles are registered in the detectors. This rescattering of hadrons modifies every hadronic bulk observable. The apparent multiplicity of resonances is suppressed as compared to a chemical equilibrium freeze-out model, because the decay products rescatter. Therefore the resonances, which decay in the early hadronic phase, cannot be identified anymore by the invariant mass method. Stable and unstable particles change their momentum distribution by more than $30\%$ through rescattering and their multiplicity is modified by resonance production and annihilation on a similar magnitude. These findings show that it is all but trivial to conclude from the final state observables on the properties of the system at an earlier time where it may have been in local equilibrium.

We report on the investigation of $\mathrm{\Delta }$(1232) production and decay in proton-proton collisions at a kinetic energy of 1.25 GeV measured with HADES. Exclusive dilepton decay channels $pp{e}^{+}{e}^{-}$ and $pp{e}^{+}{e}^{-}\gamma$ have been studied and compared with the partial-wave analysis of the hadronic $pp{\pi }^0$ channel. They allow to access both ${\mathrm{\Delta }}^{+}\to p{\pi }^0\left(e^{+}{e}^{-}\gamma \right)$ and ${\mathrm{\Delta }}^{+}\to p{e}^{+}{e}^{-}$ Dalitz decay channels. The perfect reconstruction of the well-known ${\pi }^0$ Dalitz decay serves as a proof of the consistency of the analysis. The $\mathrm{\Delta }$ Dalitz decay is identified for the first time and the sensitivity to $N-\mathrm{\Delta }$ transition form factors is tested. The $\mathrm{\Delta }$(1232) Dalitz decay branching ratio is also determined for the first time; our result is (4.19 $\pm$ 0.62 syst. $\pm$ 0.34 stat.) $\times {10}^{-5}$, albeit with some model dependence.

We analyze the density dependence of the contribution of meson-exchange currents to the lepton-nucleus inclusive cross section in the two-particle two-hole channel. The model is based on the relativistic Fermi gas, where each nucleus is characterized by its Fermi momentum $k_F$. We find that the 2p-2h nuclear response functions at their peaks scale as $A{k}_F^2$ for Fermi momentum going from 200 to 300 MeV/$c$ and momentum transfer $q$ from $2k_F$ to 2 $\mathrm{GeV}/c$. This behavior is different from what is found for the quasielastic response, which scales as $A/k_F$. Additionally, the deep scaling region is also discussed and there the usual scaling behavior is found to be preferable.

The failures of single-reference coupled-cluster theory for strongly correlated many-body systems is flagged at the mean-field level by the spontaneous breaking of one or more physical symmetries of the Hamiltonian. Restoring the symmetry of the mean-field determinant by projection reveals that coupled-cluster theory fails because it factorizes high-order excitation amplitudes incorrectly. However, symmetry-projected mean-field wave functions do not account sufficiently for dynamic (or weak) correlation. Here we pursue a merger of symmetry projection and coupled-cluster theory, following previous work along these lines that utilized the simple Lipkin model system as a test bed [J. Chem. Phys. 146, 054110 (2017)]. We generalize the concept of a symmetry-projected mean-field wave function to the concept of a symmetry projected state, in which the factorization of high-order excitation amplitudes in terms of low-order ones is guided by symmetry projection and is not exponential, and combine them with coupled-cluster theory in order to model the ground state of the Agassi Hamiltonian. This model has two separate channels of correlation and two separate physical symmetries which are broken under strong correlation. We show how the combination of symmetry collective states and coupled-cluster theory is effective in obtaining correlation energies and order parameters of the Agassi model throughout its phase diagram.

We have implemented a new variation-after-projection (VAP) calculation based on a time-odd Hartree-Fock (HF) mean field. The exact Hessian matrix of the projected energy has been successively evaluated for the first time, which makes the VAP calculation much more stable. With the time-odd mean field, the present VAP can be applied to the yrast states not only in the even-even nuclei, but also in the odd-$A$ and odd-odd ones. The VAP energies throughout all spins for some calculated $sd$-shell nuclei are very close to the corresponding shell model ones. Our calculations clearly show that the spin projection is very important in achieving a good approximation to the full shell model.

Elastic and inelastic differential cross sections for neutron scattering from ${}^{56}\mathrm{Fe}$ have been measured for several incident energies from 1.30 to 7.96 MeV at the University of Kentucky Accelerator Laboratory. Scattered neutrons were detected using a ${\mathrm{C}}_6{\mathrm{D}}_6$ liquid scintillation detector using pulse-shape discrimination and time-of-flight techniques. The deduced cross sections have been compared with previously reported data, predictions from evaluation databases ENDF, JENDL, and JEFF, and theoretical calculations performed using different optical model potentials using the talys and empire nuclear reaction codes. The coupled-channel calculations based on the vibrational and soft-rotor models are found to describe the experimental ($n,n_0$) and ($n,n_1$) cross sections well.

It is expected that in a hot QCD system, a local parity-odd domain can be produced due to nonzero chirality, which is induced from the difference of winding numbers carried by the gluon topological configuration (QCD sphaleron). This local domain is called the chiral-imbalance medium, characterized by nonzero chiral chemical potential, which can be interpreted as the time variation of the strong $CP$ phase. We find that the chiral chemical potential generates the parity breaking term in the electromagnetic form factor of charged pions. Heavy ion collision experiments could observe the phenomenological consequence of this parity-odd form factor through the elastic scattering of a pion and a photon in the medium. Then we quantify the asymmetry rate of the parity violation by measuring the polarization of the photon associated with the pion, and discuss how it could be measured in a definite laboratory frame. We roughly estimate the typical size of the asymmetry, just by picking up the pion resonant process, and find that the signal can be sufficiently larger than possible background events from parity-breaking electroweak process. Our findings might provide a novel possibility to make a manifest detection for the remnant of the strong $CP$ violation.

The lifetime of the $0_3^{+}$ state in ${}^{66}\mathrm{Ni}$, two neutrons below the $N=40$ subshell gap, has been measured. The transition $B(E2;0_3^{+}\to 2_1^{+}$) is one of the most hindered $E2$ transitions in the Ni isotopic chain and it implies that, unlike ${}^{68}\mathrm{Ni}$, there is a spherical structure at low excitation energy. We have performed extensive shell-model calculations that correctly predict this result, obtaining a spherical $0^{+}$ state at the correct energy and with an extremely low $B(E2;0_3^{+}\to 2_1^{+}$) value.

We examine, within the framework of the interacting boson model, the structural evolution along the excitation energy across the saddle points of potential wells in a finite nuclear system, and its connection with excited-state quantum phase transitions (ESQPTs). We find that transitions between $\gamma$-rigid and $\gamma$-soft shapes occur as a function of angular momentum, $L$, analogous to the Jacobi transitions occurring in rotating stars. Empirical evidence of these transitions is found in the rotational spectra of ${}^{156–162}\mathrm{Gd}$.

In association with the property of the $1/2^{+}$ state observed just above the ${}^8\mathrm{Be}\left(0^{+}\right)+n$ threshold energy in ${}^9\mathrm{Be}$, we investigate the photodisintegration cross section of an $s$ state in a simple schematic two-body model using the complex scaling method. The photodisintegration cross section, continuum level density, scattering phase shifts, and scattering length are discussed in relation with the virtual state. These scattering observables show strong divergences when a virtual state is located near the physical scattering region.

Within the framework of the relativistic Vlasov–Uehling–Uhlenbeck transport model based on the relativistic nonlinear $\mathrm{NL}\rho$ interaction, we study pion in-medium effects on the ${\pi }^{-}/{\pi }^{+}$ ratio in $\text{Au}+\text{Au}$ collisions at the energy of $E/A=400\mathrm{MeV}$. These effects include the isospin-dependent pion $s$-wave and $p$-wave potentials, which are taken from calculations based on the chiral perturbation theory and the $\mathrm{\Delta }$-hole model, respectively. We find that the ${\pi }^{-}/{\pi }^{+}$ ratio in this collision is suppressed by the pion $s$-wave potential but enhanced by the $p$-wave potential, with a net effect of a significantly suppressed ${\pi }^{-}/{\pi }^{+}$ ratio. Including also the in-medium threshold effects on $\mathrm{\Delta }$ resonance production and decay and using a nuclear symmetry energy with a slope parameter $L=59\mathrm{MeV}$ by reducing the coupling of isovector-vector $\rho$ meson to nucleon, our result is in good agreement with measured ${\pi }^{-}/{\pi }^{+}$ ratio from the FOPI Collaboration. We further investigate the pion in-medium effects on the ratio of charged pions as a function of their kinetic energies.

The structure of light antikaon-nuclear quasibound states, which consist of an antikaon $(\overline{K}=K^{-},{\overline{K}}^0)$ and a few nucleons $(N=p,n)$, such as $\overline{K}NN$, $\overline{K}NNN$, $\overline{K}NNNN$, and $\overline{K}NNNNNN$ systems, is studied with full three- to seven-body calculations. Employing a realistic $\overline{K}N$ potential based on the chiral SU(3) effective field theory with the SIDDHARTA constraint, we show that the central nucleon densities of these systems increase when the antikaon is injected, by about factor of 2 at maximum. The $\overline{K}NNNN$ system shows the largest central density, about 0.74 ${\mathrm{fm}}^{-3}$ even with the phenomenological $\overline{K}N$ potential, which is not as high as those suggested in previous studies with approximate treatments of the few-body systems. We find that the spin of the ground state of the $\overline{K}NNNNNN$ system depends on the strength of the $\overline{K}N$ attraction. Thus, the quantum number of the ground state can be another constraint on the $\overline{K}N$ interaction.

We describe the production of heavy quarkonia in $pA$ collisions within the dipole approach by assuming the dominance of the perturbative color-singlet mechanism (CSM) in the $p_T$-integrated cross section. Although accounting for a nonzero heavy $Q\text{−}\overline{Q}$ separation is a higher-twist correction that is usually neglected, we found it to be the dominant source of nuclear effects, significantly exceeding the effects of leading-twist gluon shadowing and energy loss. Moreover, this contribution turns out to be the most reliably predicted, relying on the precise measurements of the dipole cross section at the Hadron-Electron Ring Accelerator (HERA) at DESY. The nuclear suppression of quarkonia has been anticipated to become stronger with energy because the dipole cross section steeply rises. However, the measured nuclear effects remain essentially unchanged within the energy range from that of the BNL Relativistic Heavy Ion Collider (RHIC) to that of the Large Hadron Collider (LHC). A production mechanism is proposed that enhances the charmonium yield. Nuclear effects for the production of $J/\psi$, $\psi \left(2S\right)$, $\mathrm{{\rm Y}}\left(1S\right)$, and $\mathrm{{\rm Y}}\left(2S\right)$ are calculated and are in agreement with data from RHIC and LHC. The dipole description offers a unique explanation for the observed significant nuclear suppression of the $\psi \left(2S\right)\text{-to-}J/\psi$ ratio, which is related to the nontrivial features of the $\psi \left(2S\right)$ wave function.

Excited states in the proton-unbound nuclide ${}^{177}\mathrm{Au}$ were populated in the ${}^{92}\mathrm{Mo}$(${}^{88}\mathrm{Sr}, p2n$) reaction and identified using the Jurogam-II and GREAT spectrometers in conjunction with the RITU gas-filled separator at the University of Jyväskylä Accelerator Laboratory. A strongly coupled band and its decay path to the $11/2^{-}\alpha$-decaying isomer have been identified using recoil-decay tagging. Comparisons with cranked Hartree-Fock-Bogoliubov (HFB) calculations based on Skyrme energy functionals suggest that the band has a prolate deformation and is based upon coupling the odd $1h_{11/2}$ proton hole to the excited $0_2^{+}$ configuration in the ${}^{178}\mathrm{Hg}$ core. Although these configurations might be expected to follow the parabolic trend of core Hg($0_2^{+}$) states as a function of neutron number, the electromagnetic decay paths from the strongly coupled band in ${}^{177}\mathrm{Au}$ are markedly different from those observed in the heavier isotopes above the midshell. This indicates that a significant change in the structure of the underlying ${}^{A+1}\mathrm{Hg}$ core occurs below the neutron midshell.

An improvement to the single-particle structure is made to the gross theory, which is a global $\beta$-decay model. The gross theory is based on the sum rule of the intensity of the $\beta$-decay transition and a strength function. This model provides reasonable results for $\beta$-decay rates and delayed neutrons for the entire nuclear mass region. An attempt is made to improve the gross theory of nuclear $\beta$ decay by considering the change in parity at the single-particle level of ground-state nuclei. In this treatment, the nuclear matrix elements are suppressed when the parity of the single neutron and proton levels is different for the allowed transition. The assignment of parity is performed using the Woods-Saxon–type single-particle potential. The discrepancies from experimental half-lives, which appeared in the vicinity of the magic numbers of neutrons and protons, are systematically improved in the nuclear mass region.

The complex fragment emission from the decay of fully energy-relaxed composite, ${}^{44}\mathrm{Ti}^{*}$ formed via the ${}^{32}\mathrm{S}+{}^{12}\mathrm{C}$ reaction at two excitation energies, have been studied. Inclusive energy distributions of the fragments ($3\le Z\le 8$) emitted in the reaction ${}^{32}\mathrm{S}+{}^{12}\mathrm{C}$ have been measured in the angular range $\sim {16}^{\circ }–{28}^{\circ }$, at two incident energies, 200 and 220 MeV, respectively. Damped fragment yields in all the cases have been found to have the characteristic of emission from fully-energy-equilibrated composites. The binary fragment yields are found to be in good agreement with the standard statistical model predictions of the extended Hauser–Feshbach model (EHFM).

We propose a method of selecting a high-purity sample of charged current quasielastic neutrino interactions to obtain a precise reconstruction of the neutrino energy. The performance of the method was verified with several tests using genie, neut, and nuwro Monte Carlo event generators with both carbon and argon targets. The method can be useful in neutrino oscillation studies with beams of a few GeV.