A differential-plunger device was used to measure the lifetimes of the lowest states in the $\pi g_{7/2}\otimes \nu h_{11/2}$ rotational band in doubly odd ${}^{112}\mathrm{I}$ with the ${}^{58}\mathrm{Ni}({}^{58}\mathrm{Ni},3pn)$ reaction. A differential decay curve method was performed using the fully shifted and degraded $\gamma$-ray intensity measurements as a function of target-to-degrader distance. The lifetimes of the lowest three states in the $\pi g_{7/2}\otimes \nu h_{11/2}$ band in ${}^{112}\mathrm{I}$ were measured to be 124(30), 130(25), and $\le 6.5\left(5\right)\mathrm{ps}$, respectively. As the lifetimes of successive excited states in a rotational band are expected to decrease with increasing excitation energy, these measurements suggest that the order of the transitions in the established band in ${}^{112}\mathrm{I}$ may need revising and that the state tentatively assigned to be $\left(7^{-}\right)$ may not belong to the rotational band.

High spin band structures of neutron-rich ${}^{152–158}\mathrm{Pm}$ isotopes have been obtained from the measurement of prompt $\gamma$ rays of isotopically identified fragments produced in fission of ${}^{238}\mathrm{U}+{}^9\mathrm{Be}$ and detected using the VAMOS++ magnetic spectrometer and EXOGAM segmented Clover array at GANIL and also from the high statistics $\gamma \text{−}\gamma \text{−}\gamma$ and $\gamma \text{−}\gamma \text{−}\gamma \text{−}\gamma$ data from the spontaneous fission of ${}^{252}\mathrm{Cf}$ using Gammasphere. The excited states in ${}^{157}\mathrm{Pm}$ and those above the isomers in even-$A$ Pm isotopes ${}^{152,154,156,158}\mathrm{Pm}$ have been identified for the first time. The spectroscopic information on the rotational band structures in odd-$A$ Pm isotopes has been extended considerably to higher spins and the possibility of the presence of reflection asymmetric shapes is explored. The configuration assignments are based on the results of cranked relativistic Hartree-Bogoliubov calculations. From the systematics of bands in odd-$A$ Pm isotopes and weak population of opposite parity bands, octupole deformed shapes in neutron-rich Pm isotopes beyond $N=90$ seem unlikely to be present.

A precise quasielastic excitation function for the ${}^{18}\mathrm{O}+{}^{63}\mathrm{Cu}$ system has been measured at energies around the Coulomb barrier at ${\theta }_{\mathrm{LAB}}={161}^{\circ }$. The corresponding quasielastic barrier distribution has been derived. Two-neutron-, one-proton-, and α-transfer-excitation functions have also been measured at the same energies and angle. Coupled reaction channels calculations were performed to describe the experimental data. Large-scale shell-model calculations were performed to derive most of the spectroscopic amplitudes. No surface imaginary potential was necessary for the interaction potential because almost all relevant reaction channels were explicitly included in the calculation. The theoretical results were compared to the experimental quasielastic barrier distribution and a very good agreement was achieved. The comparison of the coupled reaction channel calculations and data has put in evidence several important details of the reaction mechanism of the ${}^{18}\mathrm{O}+{}^{63}\mathrm{Cu}$ system. The collectivity of the ${}^{63}\mathrm{Cu}$ nucleus has important contribution to the reaction mechanism of this system, mainly due to its first $5/2^{+}$ and $7/2^{+}$ states. It was also observed a striking influence on the reaction dynamics of the ${}^{18}\mathrm{O}$($2^{+}$) state, the two-neutron transfer and the reorientation of the target ground-state spin. The best agreement to data was achieved when the nuclear matter diffuseness for the ${}^{18}\mathrm{O}$ was assumed equal to 0.60 fm, value that we have derived in a previous paper and that is 10% greater than the ${}^{16}\mathrm{O}$ diffuseness. Another significant result was that the two-neutron transfer process is much more relevant than the one-neutron-transfer process, which suggests that the pairing correlation could play an important role in the transfer process of this system.

The chiral magnetic wave from the interplay between the chiral magnetic effect and the chiral separation effect is simulated in a box system with the periodic boundary condition based on the chiral kinetic equations of motion. Simulation results are compared with available limits from theoretical derivations, and effects of the temperature, the magnetic field, and the specific shear viscosity on the key properties of the chiral magnetic wave are discussed. Our study serves as a baseline for further simulations of chiral anomalies in relativistic heavy-ion collisions.

We present a new lattice formulation of chiral effective field theory interactions with a simpler decomposition into spin channels. With these interactions the process of fitting to the empirical scattering phase shifts is simplified, and the resulting lattice phase shifts are more accurate than in previous studies. We present results for the neutron-proton system up to next-to-next-to-next-to-leading order for lattice spacings of 1.97, 1.64, 1.32, and $0.99\mathrm{fm}$. Our results provide a pathway to ab initio lattice calculations of nuclear structure, reactions, and thermodynamics with accurate and systematic control over the chiral nucleon-nucleon force.

In the Fermi energy domain, it is extremely complex to experimentally isolate fragments and particles emitted by a hot nucleus produced during a heavy ion collision. This article presents a new method to characterize more precisely hot quasiprojectiles. It tries to take into account as accurately as possible the distortions generated by all the other potential participants of the nuclear reaction. It is quantitatively shown that this method is an improvement compared to a “classical calorimetry” used with a $4\pi$ detector array.

In nuclear thermodynamics, the determination of the excitation energy of hot nuclei is a fundamental experimental problem. Instrumental physicists have been trying to solve this problem for several years by building the most exhaustive $4\pi$ detector arrays and perfecting their calorimetry techniques. In a recent paper, a proposal for a new calorimetry, called “3D calorimetry”, was made. It tries to optimize the separation between the particles and fragments emitted by the quasiprojectile and the other possible contributions. This can be achieved by determining the experimental probability for a given nucleus of a nuclear reaction to be emitted by the quasiprojectile. It has been developed for the INDRA data. In the present work, we wanted to dissect and validate this new method of characterization of a hot quasiprojectile. So we tried to understand and control it completely to determine these limits. Using the Heavy Ion Phase Space Exploration (HIPSE) event generator and a software simulating the functioning of INDRA, we were able to achieve this goal and provide a quantitative estimation of the quality of the quasiprojectile characterization.

Volume or centrality fluctuations (CF) are one of the main uncertainties for interpreting the centrality dependence of many experimental observables. The CF is constrained by centrality selection based on particle multiplicity in a reference subevent and contributes to observables measured in another subevent. Using a Glauber-based independent source model, we study the influence of CF on several distributions of multiplicity $N$ and eccentricities ${\epsilon }_n$: $p\left(N\right),p\left({\epsilon }_n\right),p({\epsilon }_n,{\epsilon }_m)$, and $p(N,{\epsilon }_n)$, where the effects of CF are quantified using multiparticle cumulants of these distributions. In midcentral collisions, a general relation is established between the multiplicity fluctuation and resulting CF in the reference subevent. In ultracentral collisions, where distribution of particle production sources is strongly distorted, we find these cumulants exhibit rich sign-change patterns, due to observable-dependent non-Gaussianity in the underlying distributions. The details of sign-change pattern change with the size of the collision systems. Simultaneous comparison of these different types of cumulants between model prediction and experimental data can be used to constrain the CF and particle production mechanism in heavy-ion collisions. Since the concepts of centrality and CF are expected to fluctuate in the longitudinal direction within a single event, we propose to use the pseudorapidity-separated subevent cumulant method to explore the nature of intraevent fluctuations of centrality and collective dynamics. The subevent method can be applied for any bulk observable that is sensitive to centrality and has the potential to separate different mechanisms for multiplicity and flow fluctuations happening at different timescales. The forward detector upgrades at the Relativistic Heavy Ion Collider and the Large Hadron Collider will greatly enhance such studies in the future.

The dilepton transverse momentum spectra and invariant mass spectra for low $p_T<0.15$ GeV/$c$ in Au+Au collisions of different centralities at $\sqrt{s_{NN}}=200$ GeV are studied within the parton-hadron-string dynamics (PHSD) transport approach. The PHSD describes the whole evolution of the system on a microscopic basis and incorporates hadronic and partonic degrees of freedom, the dynamical hadronization of partons, and hadronic rescattering. For dilepton production in $p+p,p+A$, and $A+A$ reactions, the PHSD incorporates the leading hadronic and partonic channels (also for heavy flavors) and includes in-medium effects such as a broadening of the vector-meson spectral functions in hadronic matter and a modification of initial heavy-flavor correlations by interactions with the partonic and hadronic medium. The transport calculations reproduce well the momentum integrated invariant mass spectra from the STAR Collaboration for minimum bias Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV, while the description of the STAR data, when gating on low $p_T<0.15$ GeV/$c$, gets worse when going from central to peripheral collisions. An analysis of the transverse momentum spectra shows that the data for peripheral (60–80%) collisions are well reproduced for $p_T>0.2$ GeV/$c$, while the strong peak at low $p_T<0.15$ GeV/$c$ that shows up in the experimental data for the mass bins $(0.4<M<0.7$ GeV and $1.2<M<2.6$ GeV) is fully missed by the PHSD and cannot be explained by the standard in-medium effects. This provides a new puzzle for microscopic descriptions of low $p_T$ dilepton data from the STAR Collaboration.

Elastic scattering angular distributions of the proton drip line nucleus, ${}^9\mathrm{C}$, impinging on a ${}^{\mathrm{nat}}\mathrm{Pb}$ target have been measured for the first time at energies around three times the Coulomb barriers at the Radioactive Ion Beam Line in Lanzhou. The same measurements were made for ${}^8\mathrm{B}$ and ${}^7\mathrm{Be}$ simultaneously. The measured elastic scattering angular distribution of ${}^9\mathrm{C}$ on a lead target does not show any particular reduction at around the Coulomb rainbow angles, suggesting that the breakup coupling effect on the elastic scattering channel is very small in this energy region. A similar observation is made for ${}^8\mathrm{B}$. Analysis with the continuum discretized coupled channels (CDCC) method shows that it is the Coulomb and/or the centrifugal barriers exerted on the valence protons that counteract the breakup coupling effects on the elastic scattering channel. CDCC calculations assuming ${}^9\mathrm{C}$ to have a ${}^7\mathrm{Be}+2p$ cluster structure give elastic scattering cross sections similar to those for a ${}^8\mathrm{B}+p$ structure. The calculated breakup cross sections with these two assumed structures of ${}^9\mathrm{C}$ differ quite a bit at around the Coulomb rainbow angles, suggesting that the breakup cross sections, instead of the elastic scattering ones, are more sensitive to the structure of proton-rich nuclei at incident energies around three times the Coulomb barriers.

Background: The eikonal approximation is a high-energy reaction model, which is very computationally efficient and provides a simple interpretation of the collision. Unfortunately, it is not valid at energies around 10 MeV/nucleon, the range of energy of HIE-ISOLDE at CERN and the future ReA12 at MSU. Fukui et al. [Phys. Rev. C 90, 034617 (2014)] have shown that a simple semiclassical correction of the projectile-target deflection could improve the description of breakup of halo nuclei on heavy targets down to 20 MeV/nucleon.

Purpose: We study two similar corrections, which aim at improving the projectile-target relative motion within the eikonal approximation, with the goal to extend its range of validity down to 10 MeV/nucleon in nuclear-dominated collisions, viz. on light targets. The semiclassical correction substitutes the impact parameter by the distance of closest approach of the corresponding classical trajectory. The exact continued $S$-matrix correction replaces the eikonal phase by the exact phase shift. Both corrections successfully describe the elastic scattering of one-neutron halo nuclei.

Method: We extend these corrections and study their efficiency in describing the breakup channel. We evaluate them in the case of ${}^{11}\mathrm{Be}$ impinging on ${}^{12}\mathrm{C}$ at 20 and 10 MeV/nucleon.

Results: Albeit efficient to reproduce the elastic channel, these corrections do not improve the description of the breakup of halo nuclei within the eikonal approximation down to 20 MeV/nucleon.

Conclusions: Our analysis of these corrections shows that improving the projectile-target relative motion is not the ultimate answer to extend the eikonal approximation down to low energies. We suggest another avenue to reach this goal.

As a hot issue, exploring exotic pentaquarks is full of challenges and opportunities for both theorist and experimentalist. In this work, we focus on a type of pentaquark with the $QQqq\overline{q}$ ($Q=b,c$; $q=u,d,s$) configuration, where their mass spectrum is estimated systematically. In particular, our result indicates that there may exist some stable or narrow exotic pentaquark states. Obviously, our study may provides valuable information for further experimental search for the $QQqq\overline{q}$ pentaquarks. With the running of large Hadron collider beauty (LHCb) and forthcoming Belle II, we have a reason to believe that these predictions presented here can be tested.

We calculate the charged-current cross sections obtained at the T2K off-axis near detector for ${\nu }_{\mu }$-induced events without pions and any number of protons in the final state using transport theory as encoded in the gibuu model. In a comparison with recent T2K data the strength of the 2p2h multinucleon correlations is determined. Linking this to the isospin ($\mathcal{T}$) of the initial nuclear state, it is found that $\mathcal{T}=0$ leads to a significantly better fit of the recent cross sections obtained by T2K, thus achieving consistency of the 2p2h multinucleon correlation contributions between electron-nucleus and neutrino-nucleus reactions.

I consider a mixture of superconducting and superfluid nuclear liquids of protons coupled to the ultrarelativistic electron gas and neutrons. In the magnetohydrodynamic (MHD) approximation, the energy-momentum (stress) tensor is derived, and the entrainment contribution is found in the explicit form. It is shown that this contribution generates a force density when a superfluid velocity lag and the magnetic field are present simultaneously. This force may be important in the nuclear “pasta” phase in neutron stars, if the proton and neutron Cooper pairing in the pasta phase is taken into account. It is found that, if the liquid-crystalline matter of the pasta phase is superfluid and superconducting, then magnitude of the forces acting upon element of matter at typical magnetic field and the superfluid velocity lag, under certain conditions may become large enough to induce a critical stress in the neutron-star crust. As an application, the necessary conditions for triggering of a starquake are found in the pasta phase of neutron stars, assuming that the nuclei are flat slabs in a parallel magnetic field. The present model includes two independent local parameters: the superfluid velocity lag and the magnetic field. Possible links between the entrainment force and the magnetar starquake-triggering mechanism and some open problems are discussed.

We analyze two-derivative two-nucleon interactions in a combined pionless effective field theory and large-$N_c$ expansion. At leading order in the large-$N_c$ expansion, relationships among low-energy constants emerge. We find these to be consistent with experiment. However, it is critical to correctly address the subtraction-point dependence of the low-energy constants. These results provide additional confidence that the dual-expansion procedure is useful for analyzing low-energy few-body observables.

We investigate rod-shaped rotational states in $N=Z$ even-even nuclei from ${}^{12}\mathrm{C}$ to ${}^{32}\mathrm{S}$ by using a cranked Skyrme Hartree–Fock method. We obtain rod-shaped states in heavy nuclei up to ${}^{32}\mathrm{S}$. The rod-shaped states are stabilized at large angular momentum. Analysis using the nucleon localization measure provides consistency of the rod-shaped states with interpretation to have the $\alpha$-linear-chain structure.

A systematic analysis of giant quadrupole resonances is performed for several nuclei, from ${}^{30}\mathrm{Si}$ to ${}^{208}\mathrm{Pb}$, within the subtracted second random-phase-approximation (SSRPA) model in the framework of the energy-density-functional theory. Centroid energies and widths of the isoscalar giant quadrupole resonances are compared with the corresponding random-phase-approximation (RPA) values. We find lower SSRPA centroid energies compared to the RPA values leading, in general, to a better agreement with the experimental data. As far as the widths are concerned, we observe for both SSRPA and RPA cases a global attenuation of the single-particle Landau damping going from lighter to heavier nuclei, and we obtain, systematically, larger widths in the SSRPA model compared to the RPA case. For some selected nuclei for which high-resolution ($p,p^{\prime }$) experimental data are available, namely ${}^{40}\mathrm{Ca}$, ${}^{90}\mathrm{Zr}$, ${}^{120}\mathrm{Sn}$, and ${}^{208}\mathrm{Pb}$, the theoretical strength distributions are directly compared with the experimental spectra. We observe a significant improvement, with respect to RPA results, in the description of the spreading widths and of the fragmentation of the obtained spectra, due to the coupling between one-particle–one-hole and two-particle–two-hole configurations.

The behavior of the collective rotor in wobbling motion is investigated within the particle-rotor model for the nucleus ${}^{135}\mathrm{Pr}$ by transforming the wave functions from the $K$ representation to the $R$ representation. After reproducing the experimental energy spectra and wobbling frequencies, the evolution of the wobbling mode in ${}^{135}\mathrm{Pr}$, from transverse at low spins to longitudinal at high spins, is illustrated by the distributions of the total angular momentum in the intrinsic reference frame (azimuthal plot). Finally, the coupling schemes of the angular momenta of the rotor and the high-$j$ particle for transverse and longitudinal wobbling are obtained from the analysis of the probability distributions of the rotor angular momentum ($R$ plots) and their projections onto the three principal axes ($K_R$ plots).