Energy-dependent sum rules are useful tools in many fields of physics. In nuclear physics, they typically involve an integration of the response function over the nuclear spectrum with a weight function composed of integer powers of the energy. More complicated weight functions are also encountered, e.g., in nuclear polarization corrections of atomic spectra. Using the Lorentz integral transform method and the Lanczos algorithm, we derive a computationally efficient technique for evaluating such sum rules that avoids the explicit calculation of both the continuum states and the response function itself. Our numerical results for electric dipole sum rules of the ${}^4\mathrm{He}$ nucleus with various energy-dependent weights show rapid convergence with respect to the number of Lanczos steps. This demonstrates the usefulness of the method in a variety of electroweak reactions.

The absolute masses of four long-lived transuranium nuclides, ${}^{241,243}\mathrm{Am}$, ${}^{244}\mathrm{Pu}$, ${}^{244}\mathrm{Pu}$, and ${}^{249}\mathrm{Cf}$, in the vicinity of the deformed $N=152$ neutron shell closure have been measured directly with the Penning-trap mass spectrometer TRIGA-TRAP. Our measurements confirm the AME2012 mass values of ${}^{241,243}\mathrm{Am}$ and ${}^{244}\mathrm{Pu}$ within one standard deviation, which were indirectly determined, by decay spectroscopy studies. In the case of the ${}^{249}\mathrm{Cf}$ mass, a discrepancy of more than three standard deviations has been observed, affecting absolute masses even in the superheavy element region. The implementation of the mass values into the AME2012 network yields a reduced mass uncertainty for 84 nuclides, particularly for ${}^{244}\mathrm{Pu}$ and its strongly correlated $\alpha$ decay chains.

The effect of core excitation in the elastic scattering and breakup of a two-body halo nucleus on a stable target nucleus is studied. The structure of the weakly bound projectile is described in the weak-coupling limit, assuming a particle-rotor model. The eigenfunctions and the associated eigenvalues are obtained by diagonalizing this Hamiltonian in a square-integrable basis (pseudostates). For the radial coordinate between the particle and the core, a transformed harmonic oscillator (THO) basis is used. For the reaction dynamics, an extension of the continuum-discretized coupled-channels (CDCC) method, which takes into account dynamic core excitation and de-excitation due to the presence of noncentral parts in the core-target interaction, is adapted to be used along with a pseudostates (PS) basis.

Elastic scattering measurement for the ${}^9\mathrm{Be}+{}^{89}\mathrm{Y}$ system has been carried out at near-barrier energies with the aim of investigating the effect of breakup on the elastic channel. The energy dependence of the optical model potential for the system gives an indication of the breakup threshold anomaly (BTA) for the system. An overall repulsive real part of the dynamic polarization potential (DPP) generated due to continuum couplings using the $\alpha +{}^5\mathrm{He}$ cluster structure for ${}^9\mathrm{Be}$ is consistent with the BTA behavior observed for the system. In contrast, an attractive real part of the DPP, at all energies, is observed for similar calculations carried out using the ${}^8\mathrm{Be}+n$ cluster structure. Coupling of the 1$n$ transfer channel in addition to continuum couplings does not have a significant effect on the elastic scattering angular distributions. The experimental 1$n$ transfer cross sections show better agreement with the corresponding values obtained using the ${}^8\mathrm{Be}+n$ cluster structure calculations. Inclusive breakup-$\alpha$ cross sections are observed to form a large fraction of the reaction cross sections, especially at below-barrier energies, suggesting the dominance of the breakup channel at these energies. This also supports the BTA behavior observed for the system, reflected as the presence of a reaction channel and thus the persistence of the imaginary potential at below-barrier energies.

We present a reliable double-folding (DF) model for ${}^4\mathrm{He}$-nucleus scattering, using the Melbourne $g$-matrix nucleon-nucleon interaction that explains nucleon-nucleus scattering with no adjustable parameter. In the DF model, only the target density is taken as the local density in the Melbourne $g$ matrix. For ${}^4\mathrm{He}$ elastic scattering from ${}^{58}\mathrm{Ni}$ and ${}^{208}\mathrm{Pb}$ targets in a wide range of incident energies from 20 to 200 MeV/nucleon, the DF model with the target-density approximation (TDA) yields much better agreement with the experimental data than the usual DF model with the frozen-density approximation in which the sum of projectile and target densities is taken as the local density. We also discuss the relation between the DF model with the TDA and the conventional folding model in which the nucleon-nucleus potential is folded with the ${}^4\mathrm{He}$ density.

Energies of the two lowest $(sd{)}^2{0}^{+}$ states in ${}^{10,12}\mathrm{Be}$ and ${}^{14,16}\mathrm{C}$ are examined in a simple model that works surprisingly well. Energies are predicted for the second $(sd{)}^2{0}^{+}$ state in ${}^{10,12}\mathrm{Be}$, where they are unknown.

The half-lives of the 9/2${}^{+}$, 13/2${}^{+}$, and 15/2${}^{+}$ yrast states in the neutron-rich ${}^{67}\mathrm{Cu}$ nucleus were determined by using the in-beam fast-timing technique. The experimentally deduced E3 transition strength for the decay of the 9/2${}^{+}$ level to the 3/2${}^{-}$ ground state indicates that the wave function of this level might contain a collective component arising from the coupling of the odd proton $p_{3/2}$ with the 3${}^{-}$ state in ${}^{66}\mathrm{Ni}$. Theoretical interpretations of the 9/2${}^{+}$ state are presented within the particle-vibration weak-coupling scheme involving the unpaired proton and the 3${}^{-}$ state from ${}^{66}\mathrm{Ni}$ and within shell-model calculations with a ${}^{56}\mathrm{Ni}$ core using the jj44b residual interaction. The shell model also accounts reasonably well for the other measured electromagnetic transition probabilities.

A multihit capacity setup was used to study the decay of the dripline nucleus ${}^{31}\mathrm{Ar}$, produced at the ISOLDE facility at CERN. A spectroscopic analysis of the $\beta$-delayed three-proton decay of ${}^{31}\mathrm{Ar}$ is presented for the first time together with a quantitative analysis of the $\beta$-delayed 2$p$$\gamma$ decay. A new method for determination of the spin of low-lying levels in the $\beta$$p$ daughter ${}^{30}\mathrm{S}$ using proton-proton angular correlations is presented and used to determine that the spin of the 5.2-MeV level is most likely $3^{+}$ with $4^{+}$ also possible. The half-life of ${}^{31}\mathrm{Ar}$ is found to be 15.1(3) ms. An improved analysis of the Fermi $\beta$ strength including the $\beta$3$p$-decay mode gives a total measured branching ratio of $3.60\left(44\right)\%$, which is lower than the theoretical value found to be $4.24\left(43\right)\%$. Finally, a previously unidentified $\gamma$ transition from the isobaric analog state in the decay of ${}^{33}\mathrm{Ar}$ has been found.

The ${}^{26}\mathrm{Al}$ radioisotope is of great importance for understanding the chemical and dynamical evolution of our galaxy. Among the possible stellar sources, massive stars are believed to be the main producer of this radioisotope. Understanding ${}^{26}\mathrm{Al}$ nucleosynthesis in massive stars requires estimates of the thermonuclear reaction rates of the ${}^{26}\mathrm{Al}$${(n,p)}^{26}$Mg, ${}^{26}\mathrm{Al}$${(n,\alpha )}^{23}$Na, and ${}^{23}\mathrm{Na}$${(\alpha ,p)}^{26}$Mg reactions. These reaction rates depend on the spectroscopic properties of ${}^{27}\mathrm{Al}$ states above the neutron and alpha thresholds. In this context, the ${}^{27}\mathrm{Al}$${(p,p^{\prime })}^{27}$Al* reaction was studied at 18 MeV using a high-resolution Enge Split-Pole spectrometer. States from the ground state up to excitation energies of $\approx$14 MeV were populated. While up to the ${}^{23}\mathrm{Na}$ + $\alpha$ threshold no additional states are observed, we report for the first time 30 new levels above the ${}^{23}\mathrm{Na}$ + $\alpha$ threshold and more than 30 new states above the ${}^{26}\mathrm{Al}$ + n threshold for which excitation energies are determined with an uncertainty of 4–5 keV.

The recent discoveries of massive neutron stars, such as PSR J$0348+0432$ and PSR J$1614–2230$, have raised questions about the existence of exotic matter such as hyperons in the neutron star core. The validity of many established equations of states (EoSs) like GM1 and FSUGold are also questioned. We investigate the existence of hyperonic matter in the central regions of massive neutron stars by using relativistic mean field (RMF) theory with the recently proposed Indiana University Florida State University (IUFSU) model. The IUFSU model is extended by including hyperons to study the neutron star in $\beta$ equilibrium. The effect of different hyperonic potentials, namely $\Sigma$ and $\Xi$ potentials, on the EoS and hence the maximum mass of neutron stars has been studied. We have also considered the effect of stellar rotation since the observed massive stars are pulsars. It has been found that a maximum mass of $1.93M_{\odot }$, which is within the $3\sigma$ limit of the observed mass of PSR J$0348+0432$, can be obtained for rotating stars, with certain choices of the hyperonic potentials. The said star contains a fair amount of hyperons near the core.

We propose to study the mass spectrum of the heavy-light mesons to probe the structure of the spin-isospin correlation in the nuclear medium. We point out that the spin-isospin correlation in the nuclear medium generates a mixing among the heavy-light mesons carrying different spins and isospins such as $D^{+}$, $D^0$, $D^{*+}$, and $D^{*0}$ mesons. We use two types of correlations motivated by the skyrmion crystal and the chiral density wave as typical examples to obtain the mass splitting caused by the mixing. Our result shows that the structure of the mixing reflects the pattern of the correlation, i.e., the remaining symmetry. Furthermore, the magnitude of the mass modification provides information of the strength of the correlation.

A complete high-precision set of deuteron analyzing powers for elastic deuteron-proton ($dp$) scattering at 250 and 294 MeV/nucleon has been measured. These data and previously existing data sets for the cross section at similar energies are compared to the results of three-nucleon Faddeev calculations based on modern nucleon-nucleon ($NN$) potentials alone or combined with two models of three-nucleon forces: the Tucson-Melbourne 99 and Urbana IX. Large discrepancies between pure $NN$ theory and data, which are not resolved by the current three-nucleon forces, were found at c.m. backward angles ${\theta }_{\mathrm{c}.\mathrm{m}.}\gtrsim {120}^{\circ }$ for all the deuteron analyzing powers and the cross section. Because only small relativistic effects were found for the deuteron analyzing powers and the cross section, the inclusion of short-range components of the three-nucleon force is probably required to get a better description of the data.

Background: The Gamow-Teller response of ${}^{40}\mathrm{Ar}$ is important for the use of liquid argon as a medium for neutrino detection. An ambiguity about the Gamow-Teller strength for the excitation of $1^{+}$ states at 2290 and 2730 keV in ${}^{40}\mathrm{K}$ results in a significant uncertainty for neutrino capture rates. This ambiguity is caused by the large discrepancy observed between strengths extracted from ${}^{40}\mathrm{Ar}$($p$, $n$) charge-exchange data and the transition strengths for the analog transitions studied in the $\beta$ decay of ${}^{40}\mathrm{Ti}$.

Purpose: This study was aimed at resolving the ambiguity between the results from the ${}^{40}\mathrm{Ar}$($p$, $n$) charge-exchange and ${}^{40}\mathrm{Ti}$ $\beta$-decay data.

Method: Shell-model calculations in the $sd\text{−}pf$ shell with a new interaction (WBMB-C) were used to study differences between the structure of the transitions from ${}^{40}\mathrm{Ar}$ and ${}^{40}\mathrm{Ti}$. Distorted-wave Born approximation reaction calculations were used to investigate uncertainties in the extraction of Gamow-Teller strength from the ${}^{40}\mathrm{Ar}$($p$, $n$) data. New high-resolution data for the ${}^{40}\mathrm{Ar}$(${}^3\mathrm{He}$,$t$) reaction were used to gain further insight into the charge-exchange reaction mechanism and to provide more information to test the validity of the shell-model calculations.

Results: The shell-model calculations showed that interference between amplitudes associated with $pf$ and $sd$ components to the low-lying Gamow-Teller transitions, in combination with a difference in Coulomb energy shifts for ${}^{40}\mathrm{Ar}$ and ${}^{40}\mathrm{Ti}$, can produce the differences on the scale of those observed between the ${}^{40}\mathrm{Ar}$ charge-exchange and ${}^{40}\mathrm{Ti}$ $\beta$-decay data. In combination with the difference in nuclear penetrability of the ($p$, $n$) and (${}^3\mathrm{He}$,$t$) probes, the different contributions from amplitudes associated with transitions in the $pf$ and $sd$ shells are likely also responsible for the observed discrepancy between the ratio of the cross sections for the low-lying $1^{+}$ states in the ${}^{40}\mathrm{Ar}$($p$, $n$) and ${}^{40}\mathrm{Ar}$(${}^3\mathrm{He}$,$t$) data.

Conclusions: On the basis of this study, it is recommended to use Gamow-Teller strengths extracted from the ${}^{40}\mathrm{Ar}$($p$, $n$) data, not the ${}^{40}\mathrm{Ti}$ $\beta$-decay data, for the calculation of neutrino capture rates. Further theoretical studies are required to achieve a consistent quantitative description for the energy differences between low-lying $1^{+}$ states in ${}^{40}\mathrm{K}$ and ${}^{40}\mathrm{Sc}$ and the experimentally observed Gamow-Teller strengths.

We take a new look at the neutron radiative capture by a deuteron at thermal energy with the pionless effective field theory [EFT($\pi /$)] approach. We present in detail the calculation of $nd\to$ ${}^3\mathrm{H}\gamma$ amplitudes for incoming doublet and quartet channels leading to the formation of a triton fully in the projection method based on the cluster-configuration space approach. In the present work, we consider all possible one-body and two-body photon interaction diagrams. In fact, additional diagrams that make significant changes in the results of the calculation of the total cross section in the $nd\to$ ${}^3\mathrm{H}\gamma$ process are included in this study. The properly normalized triton wave function is calculated and taken into consideration. We compare the cross section of the dominant magnetic $M1$ transition of $nd\to$${}^3\mathrm{H}\gamma$ up to $\text{next-to-next-to-leading}\text{order}{\text{(N}}^2\text{LO)}$ with the results of the previous model-dependent theoretical calculations and experimental data. The more acceptable results for cross section ${\sigma }_{\mathrm{tot}}^{\left(2\right)}=0.297\left(\text{LO}\right)+0.124\left(\text{NLO}\right)+0.048\left({\text{N}}^2\text{LO}\right)=[0.469\pm 0.033]\text{mb}$ show order by order convergence and cutoff independence. No three-body currents are needed to renormalize observables up to ${\text{N}}^2\text{LO}$ in this process.

Nucleon-nucleon potentials are common in nuclear physics and are determined from a finite number of experimental data with limited precision sampling the scattering process. We study the statistical assumptions implicit in the standard least-squares ${\chi }^2$ fitting procedure and apply, along with more conventional tests, a tail-sensitive quantile-quantile test as a simple and confident tool to verify the normality of residuals. We show that the fulfillment of normality tests is linked to a judicious and consistent selection of a nucleon-nucleon database. These considerations prove crucial to a proper statistical error analysis and uncertainty propagation. We illustrate these issues by analyzing about 8000 proton-proton and neutron-proton scattering published data. This enables the construction of potentials meeting all statistical requirements necessary for statistical uncertainty estimates in nuclear structure calculations.

Based on a multiphase transport model, medium modifications of prompt photon-tagged jet fragmentation function are investigated by comparing prompt photon-tagged hadron azimuthal correlation in $\text{Au}+\text{Au}$ collisions (0%–40%) with that in $p+p$ collisions at $\sqrt{s_{{}_{\mathrm{NN}}}}=200$ GeV. The measured modification factor $I_{AA}$ increases with the increasing integration range of the away side, which reveals a medium-modified jet shape in which the medium enhancement of soft particles is preferentially located far away from the jet axis. $I_{AA}$ largely results from strong interactions between jets and partonic matter. However, both hadronization of coalescence and hadronic rescatterings play certain roles to modify the $I_{AA}$. These behaviors reflect a dynamical evolution of modifications of the prompt photon-tagged jet fragmentation function in high-energy heavy-ion collisions.

The transverse momentum ($p_{\mathrm{T}}$) distribution for inclusive neutral pions in the very forward rapidity region has been measured, with the Large Hadron Collider forward detector (LHCf), in proton-lead collisions at nucleon-nucleon center-of-mass energies of $\sqrt{s_{\mathit{N}N}}=5.02\mathrm{TeV}$ at the LHC. The $p_{\mathrm{T}}$ spectra obtained in the rapidity range $-11.0<y_{\mathrm{lab}}<-8.9$ and $0<p_{\mathrm{T}}<0.6\mathrm{GeV}$ (in the detector reference frame) show a strong suppression of the production of neutral pions after taking into account ultraperipheral collisions. This leads to a nuclear modification factor value, relative to the interpolated $p_{\mathrm{T}}$ spectra in proton-proton collisions at $\sqrt{s}=5.02\mathrm{TeV}$, of about 0.1–0.4. This value is compared with the predictions of several hadronic interaction Monte Carlo simulations.

We applied a new approach to determine the pole positions and residues from pion photoproduction multipoles. The method is based on a Laurent expansion of the partial-wave $T$ matrices, with a Pietarinen series representing the regular part of energy-dependent and single-energy photoproduction solutions. The method is applied to multipole fits generated by the MAID and George Washington University SAID (GWU-SAID) groups. We show that the number and properties of poles extracted from photoproduction data correspond very well to results from $\pi N$ elastic data and values cited by the Particle Data Group (PDG). The photoproduction residues provide new information for the electromagnetic current at the pole position, which are independent of background parametrizations, which is not the case for the Breit-Wigner representation. Finally, we present the photodecay amplitudes from the current MAID and SAID solutions at the pole for all four-star nucleon resonances below $W=2$ GeV.