Using the TRENTo-3D initial condition model coupled with $(3+1)$-dimensional CLVisc hydrodynamic simulations, we systematically investigate the left-right splitting of elliptic flow $\left(\mathrm{\Delta }{v}_2\right)$ for soft particles in relativistic heavy-ion collisions. Our study reveals that the final distribution characteristics of $\mathrm{\Delta }{v}_2$ primarily depend on the odd flow harmonics and $v_2$ itself. We find that the parton transverse momentum scale $k_{\text{T}}$ not only determines the geometric tilt of the QGP fireball but also significantly affects the rapidity dependence of both $v_1$ and $\mathrm{\Delta }{v}_2$, providing new insights into the splitting mechanism of $\mathrm{\Delta }{v}_2$. Furthermore, our results demonstrate that $\mathrm{\Delta }{v}_2\left(p_{\text{T}}\right)$ exhibits significant sensitivity to influences such as the subnucleonic degrees of freedom (or “hotspots”), transverse momentum scale, and fragmentation region profile. By analyzing $\mathrm{\Delta }{v}_2$ and the $\mathrm{\Delta }{v}_2/v_2$ ratio, our findings provide new constraints on the uncertainties of the QGP initial state and provide additional constraints for refining model parameters.

The excited rotational bands based on the $\nu 7/2^{+}\left[624\right]$ and $\nu 5/2^{+}\left[622\right]$ configuration in the odd-$N$ 151 isotones, ${}^{245}\mathrm{Pu}$, ${}^{247}\mathrm{Cm}$, and ${}^{249}\mathrm{Cf}$, are analyzed within the framework of the cranked shell model (CSM) with pairing correlations treated by the particle number conserving method (PNC-CSM), in which blocking effects are precisely accounted for. A systematic analysis of empirical parameters of ground-state bands in even-even nuclei highlights that neutron-rich Pu isotope exhibits stronger pairing correlations, which plays a crucial role in shaping the rotational behavior of the ground and excited bands. Microscopic calculation using PNC-CSM confirmed the relative stronger pairing strengths in neutron-rich ${}^{245}\mathrm{Pu}$. The experimental kinematic and dynamic moments of inertia are reproduced very well by the PNC-CSM calculations. The odd-$N$ excited bands allow for a comparison of the alignment behavior for two different configurations, where the $\nu j_{15/2}$ alignment is either blocked or allowed. This study marks the first instance of $\nu j_{15/2}$ alignment, which is otherwise elusive in nature. The present study demonstrates that the inclusion of higher-order ${\epsilon }_6$ deformation plays a crucial role in accurately reproducing the alignment behavior observed in $N=151$ isotones. In particular, ${\epsilon }_6$ deformation significantly delays proton alignment and enhances neutron alignment contributions. Our PNC-CSM calculations confirm that neutron alignment precedes that of $i_{13/2}$ protons in ${}^{249}\mathrm{Cf}$. These findings underscore the importance of incorporating ${\epsilon }_6$ deformation to correctly describe rotational properties in heavy actinide nuclei.

We investigate hidden-charm molecular states in ${\mathrm{\Xi }}_c^{(\prime ,*)}{\overline{D}}^{(*)}$ systems using the one-boson exchange model. By regulating the short-range interactions with parameter $a$ and cutoff $\mathrm{\Lambda }$, we found ten bound states in isoscalar systems. Our analysis reveals that if the LHCb Collaboration's $P_{cs}\left(4459\right)$ and Belle Collaboration's $P_{cs}\left(4472\right)$ pentaqurks are indeed distinct states, their mass splitting can be resolved through ${\mathrm{\Xi }}_c^{\prime }\overline{D}\text{−}{\mathrm{\Xi }}_c{\overline{D}}^{*}$ coupled-channel dynamics using consistent model parameters. This framework assigns $3/2^{-}$ and $1/2^{-}$ spin-parity quantum numbers to $P_{cs}\left(4459\right)$ and $P_{cs}\left(4472\right)$, respectively. With this consistent model parameter, we predict several new molecular candidates in the 4.3–4.7 GeV mass region, demonstrating the crucial interplay between coupled-channel effects and short-range dynamics in understanding hidden-charm pentaquarks as hadronic molecules. Additionally, we investigate the effects of $\mathrm{\Lambda }{\eta }_c$ and $\mathrm{\Lambda }J/\psi$ decay channels on the predicted molecular states, showing how these channels influence pole positions and provide insights into the detectability of these states through different production mechanisms.

We present variational Monte Carlo calculations of charge and magnetic radii in $A\le 10$ nuclei. The calculations are based on the Norfolk two- and three-nucleon interactions, and associated one- and two-nucleon electromagnetic charge and current operators derived up to next-to-next-to-next-to-leading order in the chiral expansion. The charge and magnetic radii are extracted from the respective form factors. We find that the charge radii are within 5% of the experimental values for the nuclei considered. For the magnetic radii, a comparison is available only with ${}^3\mathrm{H}$ and ${}^3\mathrm{He}$ electron scattering data that are affected by large error bars. We hope that our predictions foster an interest in precisely measuring magnetic radii of heavier systems.

In this paper, we extend the method of Kadanoff-Baym equations for open quantum systems to arbitrary kinds of systems and heat baths, either fermionic or bosonic. This includes three spacial dimensions and different potentials for the system-bath interaction or external traps. We study the quantum-mechanical formation of bound states in one and also in three dimensions with the full Kadanoff-Baym equations and compare them to more simplified approaches with and without memory effects. An in-depth examination of the thermodynamics of open systems is performed, showing perfect equilibration of the system's degrees of freedom along with a comprehensive investigation of the influence of the heat bath on the system's wave functions. The formation time, decay time, and regeneration of bound states and their dependence on the temperature and coupling strength is explored. We evaluate the nonequilibrium Kadanoff-Baym equations for the system particles, assuming that interactions are elastic two-particle collisions with the heat-bath particles. Finally, we describe in detail the method used to numerically solve the corresponding spatially heterogeneous integrodifferential equations for the set of one-particle Green's functions.

Aiming for a better understanding of the ${}^{27}\mathrm{Al}(\alpha ,n){}^{30}\mathrm{P}$ reaction, new cross-section measurements for this reaction have been carried out using ${}^{27}\mathrm{Al}$ targets of thicknesses 20 $\mu {\mathrm{g}/\mathrm{cm}}^2$ and 63 $\mu {\mathrm{g}/\mathrm{cm}}^2$ for $\alpha$-energy range of 2.5–5.2 MeV and 3.4–5.2 MeV, respectively. An array of twenty-eight ${}^3\mathrm{He}$ counters, providing high and almost flat neutron-detection efficiency up to about 3 MeV neutron energy, has been used for the experiment. The amount of ${}^{13}\mathrm{C}$ contamination in the ${}^{27}\mathrm{Al}$ target and its effect on the measured total neutron cross sections has also been reported. The measured cross sections have been interpreted using the dynamical cluster-decay model and the compound Hauser-Feshbach model.

There has been increasing interest in recent years in using relativistic heavy-ion collisions to probe nuclear structure, such as static nuclear deformation. Here we discuss the role of quantum zero-point fluctuations of the surface vibrations of spherical nuclei in relativistic heavy-ion collisions. To this end, we employ an approach to describe the vibration in the space-fixed frame, which has been well established in the field of low-energy heavy-ion fusion reactions. We particularly consider the quadrupole vibration of ${}^{58}\mathrm{Ni}$ in the ${}^{58}\mathrm{Ni}+{}^{58}\mathrm{Ni}$ reaction and the octupole vibration of ${}^{208}\mathrm{Pb}$ in the ${}^{208}\mathrm{Pb}+{}^{208}\mathrm{Pb}$ reaction. We show that the surface vibration leads to comparable eccentricity parameters to those for static deformation, while they give significantly different distributions of the initial states, suggesting the importance of the proper treatment of the surface vibrations in heavy-ion collisions. We perform similar analysis also for triaxial deformation and gamma-soft vibration.

${}^{12}\mathrm{C}$ and ${}^{16}\mathrm{O}$ nuclei represent essential elements for life on Earth. The study of their formation plays a key role in understanding heavy element nucleosynthesis and stellar evolution. In this paper we present the study of ${}^{12}\mathrm{C}$ and ${}^{16}\mathrm{O}$ nuclei as systems composed of $\alpha$-particle clusters using a short-range effective field theory–inspired approach. The fundamental and excited states of the studied nuclei are calculated within an ab initio approach using the hyperspherical harmonics method. Thanks to the two-body potential and fine-tuning of the three-body force, we have found the ${}^{12}\mathrm{C}$ system nicely reproduced by theory. However, for the ${}^{16}\mathrm{O}$ case, it is necessary to include a four-body force in order to achieve agreement with the experimental data.

High-spin states in neutron-rich ${}^{96}\mathrm{Nb}$ nucleus have been investigated by using in-beam $\gamma$ ray spectroscopy with the ${}^{82}\mathrm{Se}({}^{18}\mathrm{O},p3n){}^{96}\mathrm{Nb}$ reaction at beam energies of 82 and 88 MeV. Particle $-\gamma -\gamma$ coincidence measurements employing CsI and HPGe arrays were utilized to enhance selectivity for Nb isotopic products. The decay sequences of previously known states have been extended up to $\left({25}^{-}\right)$ through the identification of fourteen new $\gamma$ rays. The spins and parities of most $\gamma$ rays in ${}^{96}\mathrm{Nb}$ have been assigned for the first time using angular distribution of $\gamma$ rays and polarization analysis. Level structures in ${}^{96}\mathrm{Nb}$ have been analyzed through systematic comparisons with neighboring nuclei and shell model calculations utilizing the GWBXG and SNET interactions. It is shown that the inclusion of proton core excitation relative to the Z = 38 subshell closure seems necessary to better reproduce high-spin states at $J\sim (19–25)\hslash$ with excitation energies above 6.2 MeV.

We aim to constrain the equation of state of nuclear matter by comparing calculations with the $\mathrm{SMASH}$ transport model to directed and elliptic flow measurements for protons and deuterons performed by the HADES collaboration in a systematic way. A momentum-dependent term is included in the potential for which we show that it is needed to describe flow data. We further incorporate a simple symmetry potential in the transport model and present constraints on the stiffness of the equation of state of nuclear matter at saturation density and on the symmetry potential. The constraints are obtained by performing a Bayesian analysis such that we can also provide an uncertainty for the estimated parameters. The posterior distribution is obtained by Markov chain Monte Carlo sampling for which we emulate the transport model with a Gaussian process to lower computational costs. We find that a relatively stiff equation of state is favoured in our analysis with a small uncertainty whereas the constraints obtained for the symmetry potential are rather loose.

The quantum-mechanical definition of probability, the uncertainty principle, and Poincaré invariance provide strong basic restrictions on the ability to define spatial densities associated with form factors describing the properties of confined systems of relativistically moving constituents. Despite this, many papers ignore one or more of these restrictions. Here I show how to obtain time-independent, two-dimensional densities that are consistent with the stated restrictions. This is done using the light-front, infinite momentum frame formalism. Two-dimensional density interpretations of the axial-vector form factor and all three gravitational form factors is obtained. The resulting mass radius is smaller than the charge radius. Additionally, an expression of a two-dimensional mass density related to the trace of the energy momentum tensor is obtained. I also show that all known methods for finding three-dimensional densities—using the Breit frame, Abel transformations, Wigner distributions, and spherically symmetric wave packets with vanishing spatial extent—violate the basic restrictions in different ways. Furthermore, the use of the latter leads to densities that vanish almost everywhere in space as time increases from an initial value.

Cyclotron Radiation Emission Spectroscopy (CRES) is a technique for precision measurements of kinetic energies of charged particles, pioneered by the Project 8 experiment to measure the neutrino mass using the tritium end-point method. It was recently employed for the first time to measure the molecular tritium spectrum and place a limit on the neutrino mass using a cubic-centimeter-scale detector. Future direct neutrino mass experiments are developing the technique to overcome the systematic and statistical limitations of current detectors. This paper describes one such approach, namely the use of antenna arrays for CRES in free space. Phenomenology, detector design, simulation, and performance estimates are discussed, culminating with an example design with a projected sensitivity of $m_{\beta }<0.04\mathrm{eV}/c^2$. Prototype antenna array measurements are also shown for a demonstrator-scale setup as a benchmark for the simulation. By consolidating these results, this paper serves as a comprehensive reference for the development and performance of antenna arrays for CRES.

Resonances in ${}^7\mathrm{Be}$ which decay into the ${}^3\mathrm{He}+\alpha$ exit channel have been measured with improved precision using preexisting data sets. The energy and width of the $J^{\pi }=7/2^{-}$ state have been extracted from an invariant-mass study of projectile-breakup products originating from interactions of an $E/A=10.7-\mathrm{MeV}{}^{10}\mathrm{C}$ beam on Be and C targets. The excitation energy of this state (from the pole of the $S$ matrix) is determined to be $E^{*}=4.545\left(6\right)$ MeV, a factor of 8 improvement in precision as compared to the ENSDF value. This improvement is enabled by fine tuning the detector calibrations using calibration resonances in ${}^6\mathrm{Li}, {}^7\mathrm{Li}, {}^6\mathrm{Be}, {}^9\mathrm{B}$, and ${}^{12}\mathrm{C}$ whose decay energies are known to high precision. The $J^{\pi }=7/2^{-}$ resonance in ${}^7\mathrm{Be}$ can now itself be used as a calibration resonance in invariant-mass experiments. This utility is particularly helpful for ${}^3\mathrm{He}$ energy calibrations of CsI(Tl) detectors which are often used in detector arrays employed for measurements with fast beams. This utility is demonstrated with a data set associated with $E/A=70$-MeV ${}^7\mathrm{Be}$ beams which are inelastically excited to the $7/2^{-}$ and $5/2_1^{-}$ resonances. Again using the pole of the $S$ matrix as the definition of the resonance parameters, the fitted excitation energy of the $5/2_1^{-}$ resonance is 6.376(17) MeV, approximately 300 keV lower than the ENSDF value. Its width of 565(4) keV is roughly half of the ENSDF value.

In the present work, we have done a systematic study of β-decay properties such as electron spectral shapes, shape factors, and $\text{log}ft$ values for the higher forbidden nonunique ${\beta }^{-}$ transitions in the mass region $A=85–123$. We have performed the nuclear shell model calculations to explore the sensitivity of the electron spectral shapes for different axial-vector-coupling constants $g_A=0.8–1.27$. The effective interactions GWBXG, G-matrix, SNET, and SN100PN are used for different model spaces. In the present work, we have computed the electron spectral shapes of ${}^{85}\mathrm{Br}, {}^{87}\mathrm{Rb}, {}^{93}\mathrm{Zr}, {}^{97}\mathrm{Zr}, {}^{101}\mathrm{Mo}, {}^{115}\mathrm{Cd}, {}^{117}\mathrm{Cd}, {}^{119}\mathrm{In}, {}^{123}\mathrm{Sn}$, and ${}^{135}\mathrm{Cs}$ by constraining the small relativistic nuclear matrix element from conserved-vector-current hypothesis. We have found that the electron spectral shapes are strongly dependent on $g_A$ except the second forbidden nonunique ${\beta }^{-}$ transition ${}^{93}\mathrm{Zr}$.

The momentum-dependent interaction (MDI) model, which has been widely used in microscopic transport models for heavy-ion collisions (HICs), is extended to include three different momentum-dependent (MD) terms and three zero-range density-dependent (DD) terms, and is dubbed the MDI3Y model. Compared to the MDI model, the single-nucleon potential in the MDI3Y model exhibits more flexible MD behaviors, e.g., (1) the nucleon optical model potential $U_0$ in symmetric nuclear matter can have very different high energy behaviors while nicely describe the known data at lower energies; (2) the isoscalar nucleon effective mass $m_s^{*}$ can have a peak structure at subsaturation densities; and (3) the nuclear symmetry potential $U_{\mathrm{sym}}$ can display a nonmonotonic momentum dependence. Furthermore, the inclusion of three zero-range DD interactions follows the idea of Fermi momentum expansion, allowing more flexible variation for the largely uncertain high-density behaviors of the nuclear matter equation of state (EOS), especially the symmetry energy. Moreover, we also obtain the corresponding Skyrme-like energy density functional through density matrix expansion of the finite-range exchange interactions. Based on the MDI3Y model, we construct four interactions with the same symmetry energy slope parameter $L=35$ MeV but different momentum dependences of $U_{\mathrm{sym}}$, by fitting the empirical nucleon optical potential, the empirical properties of symmetric nuclear matter, the microscopic calculations of the pure neutron matter EOS, and the astrophysical constraints on neutron stars. In addition, two interactions with $L=55$ and 75 MeV are also constructed for comparison. Using these MDI3Y interactions, we study the properties of nuclear matter and neutron stars. These MDI3Y interactions, especially those with nonmonotonic momentum dependence of $U_{\mathrm{sym}}$, will be potentially useful in transport model analyses of HIC data to extract the nuclear matter EOS and the isospin splitting of nucleon effective masses.

Many common Skyrme functionals present ferromagnetic instabilities or unrealistic density dependence of the spin-dependent Landau parameters. To solve these problems, we consider the Skyrme interaction as a density-functional rather than a density-dependent two-body force. This allows us to adjust the spin-dependent terms of the extended Skyrme functionals of our previous paper [M. Duan and M. Urban, Phys. Rev. C 110, 065806 (2024)] independently without altering the properties of spin-saturated matter. The parameters of the spin-dependent terms are determined by fitting the Landau parameters $G_0$ and $G_0^{\prime }$ in neutron matter and symmetric nuclear matter and the effective-mass splitting of up and down particles in spin-polarized matter to the results of microscopic calculations. Using these parametrizations, called Sky3s and Sky4s, the spin-related properties of nuclear matter are in good agreement with the microscopic results. As an application, we compute response functions and neutrino scattering rates of neutron-star matter with these functionals having realistic effective masses and Landau parameters.