The level scheme of ${}^{91}\mathrm{Mo}$ has been studied using the GALILEO $\gamma$-ray spectrometer at Laboratori Nazionali di Legnaro, INFN. Five transitions together with four levels are identified for the first time by the $\gamma \text{−}\gamma$ coincidence measurement, considerably enriching the negative band in ${}^{91}\mathrm{Mo}$. The discrepancy in the previous parity assignments for the states higher than 3807.5 keV has been clarified with the help of new experimental results. A shell-model calculation employing the JUN45 interaction is performed in order to get a further understanding of the level structure of ${}^{91}\mathrm{Mo}$. Being close to $N=50$ shell closure, the weak-coupling approximation between the valence $g_{9/2}$ neutron-hole with the even-even core $\left({}^{92}\mathrm{Mo}\right)$ is discussed in ${}^{91}\mathrm{Mo}$.

High-spin states of ${}^{114}\mathrm{In}$ were populated using the reaction ${}^{110}\mathrm{Pd}({}^7\mathrm{Li}, 3n){}^{114}\mathrm{In}$ at a beam energy of 26 MeV. More than 30 new $\gamma$ transitions and 20 new levels are identified in ${}^{114}\mathrm{In}$. In total, three new bands and a short cascade are observed, among which a new negative-parity $\mathrm{\Delta }I=2$ band built on the $\pi g_{9/2}^{-2}{d}_{5/2}\otimes \nu h_{11/2}$ configuration before the backbend and the $\pi g_{9/2}^{-2}{d}_{5/2}\otimes \nu h_{11/2}^3$ configuration after the backbend is established. The properties of this band are discussed based on the classical particle-rotor model calculations. The predicted $B\left(E2\right)$ and ${\Im }^{\left(2\right)}/B\left(E2\right)$ ratios indicate that the $\mathrm{\Delta }I=2$ band after the backbend, has the characteristics of antimagnetic rotation. Meanwhile, the two-shears-like mechanism for the possible antimagnetic rotational band is examined by investigating the orientation of the angular momenta. A new positive-parity $\mathrm{\Delta }I=1$ band with the configuration of $\pi g_{9/2}^{-1}\otimes \nu (g_{7/2}/d_{5/2})h_{11/2}^2$ is observed.

We revisit the role of shake-up and shake-off effects in neutrinoless double-$\beta$ decay, following earlier work by Drukarev et al. [Phys. Rev. C 94, 035504 (2016)]. We find in agreement with Drukarev et al. that the $Q$ value of the decay is reduced by any atomic excitation in the final-state but not by the difference in atomic binding energy of the initial and final state atoms, as was recently suggested by Mei et al. [Mod. Phys. Lett. A 37, 2250058 (2022)] and Mei et al. [Nucl. Phys. A. 1032, 122623 (2023)]. We discuss how the absorption of subsequent atomic de-excitation ejecta shifts the neutrinoless double-$\beta$ decay peak back to its nominal value. We propose an in situ experimental verification of these ideas, and discuss the impact of shake-up and shake-off on two-neutrino double-$\beta$ decay spectral shapes.

Background: Understanding the mechanism of the quasifission reaction is important, because it is an essential competitor to the fusion reaction leading to superheavy elements. However, it is a challenge to separate the quasifission and fusion-fission components.

Purpose: This paper provides a dynamics description of the ${}^{24}\mathrm{Mg}+{}^{178}\mathrm{Hf}$ reaction at laboratory beam energy of 145 MeV, and studies contributions of quasifission and fusion-fission in the reaction.

Method: The Boltzmann-Uehling-Uhlenbeck model is improved to study the heavy-ion collision at incident energy near the Coulomb barrier. A method is developed to determine the window of the dinuclear system during the evolution.

Results: It is shown that the fusion occurs with a large percentage in the central collision, and the quasiinelastic scattering occurs mainly in the peripheral collision. The quasifission competes with the fusion in collisions with small impact parameters. It is found that the cross sections of quasifission decrease and those of fusion increase with increasing surface energy or incompressibility. The mass-angular correlation of the quasifission events shows the mass asymmetry. The fragments emitted at the front angle are targetlike fragments and those at the back angle are projectilelike fragments. Furthermore, the differential cross sections at the angles $0^{\circ }$ and ${180}^{\circ }$ are larger than that at ${90}^{\circ }$.

Conclusions: By comparing the calculations of the mass distribution and mass-angular correlation to the data, it is deduced that the compound nucleus fission plays a main role and accounts for the characteristic of fragment observables in the ${}^{24}\mathrm{Mg}+{}^{178}\mathrm{Hf}$ reaction at laboratory beam energy of 145 MeV.

An analysis of the asymmetric reactions ${}^{40,48}\mathrm{Ca}+{}^{12}\mathrm{C}$ at 25 and 40 MeV/nucleon is presented. Data were collected with six modules of the FAZIA array. The analysis is focused on the breakup channel of sources produced in dissipative collisions, partially corresponding to incomplete fusion processes. The study was performed both on detected fragments and on some resonances reconstructed by means of particle-fragment correlations, with a focus on the evolution of the breakup channel with the beam energy and the neutron content of the system, looking in particular at the relative velocity between the breakup fragments. Results show that also carbon fragments reconstructed by means of particle correlations can be in large part interpreted as the light partner of a scission.

We use $3+1$ dimensional quasiparticle anisotropic hydrodynamics (aHydroQP) to make predictions for kaon Hanbury-Brown–Twiss (HBT) radii in 200 GeV and 5.02 TeV heavy-ion collisions. Using previously determined aHydroQP parameters, we compute kaonic HBT radii and their ratios as a function of the mean transverse momentum of the pair $k_T$. We first consider Au-Au collisions at 200 GeV, finding good agreement between aHydroQP predictions and experimental data up to $k_T\approx 0.8$ GeV. We then present predictions for kaonic HBT radii and their ratios in 5.02 TeV Pb-Pb collisions. Our aHydroQP predictions do not exhibit a clear $k_T$ scaling of the pion and kaon source radii, however, an approximate transverse mass $m_T$ scaling is observed, particularly at 200 GeV.

Collective flows of protons and deuterons for $\text{Au}+\text{Au}$ collisions at beam energy $E_{\text{beam}}=1.23A \mathrm{GeV}$ were simulated by an isospin-dependent quantum molecular dynamics model. Two coalescence models, namely, naive coalescence and dynamical coalescence models, are compared for the formation of deuterons. After a reasonable agreement of the proton and deuteron rapidity spectra with the high acceptance dielectron spectrometer data is obtained, we apply an event-plane method to calculate the first four order collective flow coefficients and the ratios of $\langle v_4\rangle /{\langle v_2\rangle }^2$ and $\langle v_3\rangle /\left(\langle v_1\rangle \langle v_2\rangle \right)$ and observe the scaling of the number of constituent nucleons between protons and deuterons. In addition, the dependence of ${\varepsilon }_n$ versus $\langle v_n\rangle$ and the ratio $\langle v_n\rangle /{\varepsilon }_n$ on the centrality is obtained. Finally, the Pearson coefficients $\text{corr}(v_n,v_m)$ between the first four harmonic flows for protons and deuterons are studied as a function of rapidity and centrality.

We investigate the capabilities of the Nambu–Jona-Lasinio model to describe and reproduce fundamental vacuum properties of quantum chromodynamics, notably the hadronic spectrum. Mesons are described as quark-antiquark bound states at the level of the random phase approximation of the Bethe-Salpeter equation, while baryons are characterized as quark-diquark bound states within the static approximation of the Faddeev equation. Within a Bayesian framework, we constrain the model by phenomenologically known quantities and study the implications on its parameters and predictions in vacuum, as well as the correlations between the two. We find that within our framework the vacuum masses of mesons and baryons can be reasonably well reproduced. Scalar diquarks need to be significantly bound in order to correctly reproduce the masses of the baryon octet, therefore enforcing values of the scalar diquark coupling larger than what is suggested by the canonical Fierz values. These findings could have important implications on the phenomenology of strongly interacting matter at high temperature and density as well as of compact star physics.

We study the equation of state of dense baryon matter within the relativistic mean-field model, and we include $\mathrm{\Delta }\left(1232\right)$ isobars in the Indiana University–Florida State University (IUFSU) model with hyperons and consider the possibility of kaon meson condensation. We find that it is necessary to consider the $\mathrm{\Delta }$ resonance state inside a massive neutron star. The critical density of kaon mesons and hyperons is shifted to a higher density region; in this respect an early appearance of $\mathrm{\Delta }$ resonances is crucial to guarantee the stability of the branch of hyperonized star with the difference of the coupling parameter $x_{\sigma \mathrm{\Delta }}$ constrained based on the QCD rules in nuclear matter. The $\mathrm{\Delta }$ resonance produces a softer equation of state in the low density region, which makes the tidal deformability and radius consistent with the observation of GW170817. As the addition of new degrees of freedom will lead to a softening of the equation of state, the $\sigma$-cut scheme, which states that the decrease of neutron star mass can be lowered if one assumes a limited decrease of the $\sigma$-meson strength at ${\rho }_B$ (${\rho }_B>{\rho }_0$), finally we get a maximum mass neutron star with $\mathrm{\Delta }$ resonance heavier than $2M_{\odot }$.

${}^{180\mathrm{m}}\mathrm{Ta}$ is nature's rarest (quasi) stable isotope and its astrophysical origin is an open question. A possible production site of this isotope is the slow neutron capture process in asymptotic giant branch stars, where it can be produced via neutron capture reactions on unstable ${}^{179}\mathrm{Ta}$. We report a new measurement of the ${}^{179}\mathrm{Ta}(n,\gamma ){}^{180}\mathrm{Ta}$ cross section at thermal-neutron energies via the activation technique. Our results for the thermal and resonance-integral cross sections are $952\pm 57$ and $2013\pm 148$ b, respectively. The thermal cross section is in good agreement with the only previous measurement [Phys. Rev. C 60, 025802 (1999)], while the resonance integral is different by a factor of $\approx 1.7$. While neutron energies in this work are smaller than the energies in a stellar environment, our results may lead to improvements in theoretical predictions of the stellar cross section.

We extend our previous investigation of the effects of prehydrodynamic evolution on final-state observables in heavy-ion collisions [38] to smaller systems. We use a state-of-the-art hybrid model for the numerical simulations with optimal parameters obtained from a previous Bayesian study. By studying $p\text{−}\mathrm{Pb}$ collisions, we find that the effects due to the assumption of a conformal evolution in the prehydrodynamical stage are even more important in small systems. We also show that this effect depends on the time duration of the pre-equilibrium stage, which is further enhanced in small systems. Finally, we show that the recent proposal of a free-streaming with subluminal velocity for the pre-equilibrium stage, thus effectively breaking conformal invariance, can alleviate the contamination of final-state observables. Our study further reinforces the need for moving beyond conformal approaches in pre-equilibrium dynamics modeling, especially when extracting transport coefficients from hybrid models in the high-precision era of heavy-ion collisions.

We have developed a next-generation hybrid event-by-event three-fluid hydrodynamic model, suitable for simulations of heavy-ion collisions in the energy range from few up to tens of GeV per colliding $NN$ pair. At such energies the interpenetration time of the nuclei is of the same order as the lifetime of the system, however, this model treats the initial phase hydrodynamically. Thanks to that it is more sensitive to the equation of state than one-fluid models with initial states being parametrized or generated by transport approach. Hence, our model is well designed for simulations at collision energies, at which matter in the vicinity of the quantum chromodynamics critical endpoint is expected. The construction of the model is explained and basic observables like hadron spectra in rapidity and transverse momentum, as well as elliptic flow are calculated.

The impact of dynamic pairing correlations and their interplay with Coulomb antipairing effects on the systematic of the spontaneous fission half-lives for the nuclei ${}^{240–250}\mathrm{Cm}$ and ${}^{240–250}\mathrm{Cf}$ is analyzed, using a hierarchy of approximations based on the parametrization D1M of the Gogny energy density functional (EDF). First, the constrained Hartree-Fock-Bogoliubov (HFB) approximation is used to compute deformed mean-field configurations, zero-point quantum corrections and collective inertias either by using the Slater approximation to Coulomb exchange and neglecting Coulomb antipairing or by fully considering the exchange and pairing channels of the Coulomb interaction. Next, the properties of the least action and least energy fission paths are compared. In the least action case, pairing is identified as the relevant degree of freedom in order to minimize the action entering the Wentzel-Kramers-Brillouin (WKB) approximation to the tunneling probability through the fission barrier. Irrespective of the treatment of Coulomb exchange and antipairing, it is shown that the least action path obtained taking into account the pairing degree of freedom leads to stronger pairing correlations that significantly reduce the spontaneous fission half-lives $t_{\text{SF}}$ improving thereby the comparison with the experiment by several orders of magnitude. It is also shown that the Coulomb antipairing effect is, to a large extent, washed out by the least action procedure and therefore the $t_{\text{SF}}$ values obtained by the two different treatments of the Coulomb exchange and pairing are of similar quality.

With a motivation to find out the systematics for the low-energy ($\approx 4$–7 MeV/nucleon) incomplete fusion reactions, the experimentally measured excitation functions for evaporation residues, which were populated during the interactions of ${}^{18}\mathrm{O}$ with ${}^{159}\mathrm{Tb}$ target nuclei, have been studied. The analysis clearly exhibits that the $xn/pxn$ channels are populated to a large extent through the complete fusion processes. Although, the production cross-section of the $\alpha$-emitting channels, despite of deducting the precursor decay contribution, found to be significantly under-estimated by the statistical model predictions. The observed enhancement, which may be attributed due to the involvement of break-up fusion processes, is found to be get larger with the incident energy. In addition, the present work in light of the literature data imparts the reliance of incomplete fusion processes on various entrance channel parameters, such as the mass-asymmetry of the interacting partners, fissility parameter and also on the $Z_P{Z}_T$ (Coulomb factor). These systematics inarguably indicates the projectile type dependency of the incomplete fusion reactions, and the results may be explained on the basis of the $\alpha \text{−}Q$ value of the projectile. Furthermore, an attempt has been made to explain the trends of incomplete fusion fractions through the total asymmetry parameter and the system parameter, where system parameter seems to explain the data more satisfactorily, as it incorporates the Coulomb factor as well as the masses of the interacting partners.

Thermodynamic and chemical two-body correlations of the isotope-resolved clusters are measured in ${}^{86}\mathrm{Kr}+{}^{208}\mathrm{Pb}$reactions at 25 MeV/u. The yield and kinetic variables of the $A=3$ isobars are analyzed in coincidence with the intermediate mass fragments of $6\le A\le 11$. While the velocity spectra of both $t$ and ${}^3\mathrm{He}$ exhibit scaling behavior over the type of the intermediate mass fragments, the yield ratios of $t/{}^3\mathrm{He}$ correlate reversely to the neutron-to-proton ratio $N/Z$ of the latter, showing the ping-pong modality of the $N/Z$ of the emitted particles. The commonality that the $N/Z$ of the residues keeps the initial system value is extended to the cluster emission in heavy ion reactions. The comparison to transport model calculations to the data is discussed.

We extend the renormalizability study of the formulation of chiral effective field theory with a finite cutoff, applied to nucleon-nucleon scattering, by taking into account nonperturbative effects. We consider the nucleon-nucleon interaction up to next-to-leading order in the chiral expansion. The leading-order interaction is treated nonperturbatively. In contrast to the previously considered case when the leading-order interaction was assumed to be perturbative, new features related to the renormalization of the effective field theory are revealed. In particular, more severe constraints on the leading-order potential are formulated, which can enforce the renormalizability and the correct power counting for the next-to-leading-order amplitude. To illustrate our theoretical findings, several partial waves in the nucleon-nucleon scattering, ${}^3\mathrm{P}_0$, ${}^3\mathrm{S}_1\text{−}{}^3\mathrm{D}_1$, and ${}^1\mathrm{S}_0$ are analyzed numerically. The cutoff dependence and the convergence of the chiral expansion for those channels are discussed.

We have employed the cranked Nilsson-Strutinsky and cranked Nilsson-Strutinsky-Bogoliubov methods to predict the structure of the observed high-spin rotational bands in ${}^{137}\mathrm{Nd}$. Our study is motivated in particular by a previous observation of a rotational band more than 4 MeV above yrast. We discuss both possible interpretations of this band and in this connection also the HD band and the terminating states expected around $I=45$.

The dependence of the optical Cook potential on the bombarding energies of reactions involving ${}^{6,7}\mathrm{Li}$ projectiles has been analyzed. It has been found that, for reactions occurring close to or below the Coulomb barrier, the depth of the imaginary potential should be reduced from the value originally proposed by Cook in order to achieve better agreement with experimental elastic data. A modified version of the Cook potential is presented for both lithium isotopes, and its results are compared with those obtained using other existing optical potentials. Finally, the effects of the corrections made to the original Cook potential are studied in a one-neutron transfer case, highlighting the importance of using the correct optical potential for different reaction channels.

A modified version of the density dependent covariant density-functional model proposed in [Astrophys. J. 930, 17 (2022)] is employed in a Bayesian analysis to determine the equation of state (EOS) of dense matter with nucleonic degrees of freedom. Various constraints from nuclear physics and microscopic calculations of pure neutron matter (PNM) along with a lower bound on the maximum mass of neutron stars (NSs) are imposed on the EOS models to investigate the effectiveness of progressive incorporation of the constraints, their compatibility as well as correlations among parameters of nuclear matter and properties of NSs. Our results include the different roles played by pressure and energy per particle of PNM in constraining the isovector behavior of nuclear matter; tension with the values of Dirac effective mass extracted from spin-orbit splitting; correlations between the radius of the canonical mass NS and second- and third-order coefficients in the Taylor expansion of energy per particle as a function of density; correlation between the central pressure of the maximum mass configuration and Dirac effective mass of the nucleon at saturation. For some of our models the tail of the NS maximum mass reaches $2.7M_{\odot }$, which means that the secondary object in GW190814 could have been a NS.