We develop an asymmetric relativistic Fermi gas model for the study of the electroweak nuclear response in the quasielastic region. The model takes into account the differences between neutron and proton densities in asymmetric $(N>Z)$ nuclei, as well as differences in the neutron and proton separation energies. We present numerical results for both neutral and charged-current processes, focusing on nuclei of interest for ongoing and future neutrino oscillation experiments. We point out some important differences with respect to the commonly employed symmetric Fermi gas model.

Weak interaction in nuclei represents a well-known venue for testing many of the fundamental symmetries of the Standard Model. In particular, neutrinoless double-$\beta$ decay offers the possibility to test beyond Standard Model theories predicting that neutrinos are Majorana fermions and the lepton number conservation is violated. This paper focuses on an effective field theory approach to neutrinoless double-$\beta$ decay for extracting information regarding the properties of the beyond Standard Model Lagrangian responsible for this process. We use shell model nuclear matrix elements and the latest experimental lower limits for the half-lives to extract 12 lepton-number-violating parameters of five nuclei of experimental interest and lower limits for the energy scales of the new physics. Using the most stringent limits that we obtain for the values of the lepton-number-violating parameters, we predict new half-life limits for the other nuclei of experimental interest, in the case of 12 neutrino double-$\beta$ decay mechanisms. We provide an analysis that could reveal valuable information regarding the dominant neutrinoless double-$\beta$ decay mechanism, if experimental half-life data become available for different isotopes.

We consider a neutrino-free hot neutron star that contains antikaon condensates in its core and is at finite entropy per baryon. We find the equation of state for a range of entropies and antikaon optical potentials and generate the mass profile of static as well as rotating stars. Rotation induces many changes in the stellar equilibrium, and hence its structural properties evolve. In this work, we report the effect of rotation on the mass and shape of a hot neutron star for different equations of state and thermodynamic conditions. The temperature profile of a hot, static neutron star is also explored. We also make a crude estimate of the amplitude of gravitational waves emitted by an axisymmetric rotating NS with high magnetic field.

Background: An adiabatic distorted-wave approximation (ADWA) study of three-body $(d,p)$ transfer reactions [G. W. Bailey, N. K. Timofeyuk, and J. A. Tostevin, Phys. Rev. Lett. 117, 162502 (2016)] reported strong sensitivity of cross sections to the neutron-proton $\left(np\right)$ interaction model when the nucleon-nucleus optical potential is nonlocal.

Purpose: The verification of this unusual finding using more reliable methods is aimed for in the present work.

Methods: A rigorous Faddeev-type three-body scattering theory is applied to the study of $(d,p)$ transfer reactions. The equations for transition operators are solved in the momentum-space partial-wave framework.

Results: Differential cross sections for ${}^{26}\mathrm{Al}(d,p){}^{27}\mathrm{Al}$ reactions are calculated using nonlocal nuclear optical potentials and a number of realistic $np$ potentials. Only a weak dependence on the $np$ force model is observed, typically one order of magnitude lower than in the previous ADWA study. The shape of the angular distribution of the experimental data is well reproduced.

Conclusions: Cross sections of $(d,p)$ transfer reactions calculated using a rigorous three-body method show little sensitivity to the $np$ interaction model. This indicates a failure of the ADWA in the context of nonlocal potentials. Some evident shortcomings of the ADWA are pointed out.

In this article we report on the observation of new yrast and non-yrast states in ${}^{136}\mathrm{I}$, populated in the prompt-$\gamma$ spectroscopy EXILL campaign at the ILL using both ${}^{235}\mathrm{U}$(n,f) and ${}^{241}\mathrm{Pu}$(n,f) reactions. We propose an extension of the level scheme and interpretation of the new spectroscopic results in comparison to state-of-the-art shell-model calculations. We discuss the role of the proton $d_{5/2}$ orbital in the structure of this nucleus with $Z=53$ and the energy split between the $\pi d_{5/2}\text{and}\pi g_{7/2}$ orbitals. We also provide a complete overview of all experimental information about this nucleus and include new data from ${}^{252}\mathrm{Cf},{}^{248}\mathrm{Cm}$ fission and $\beta$ decay of ${}^{136}\mathrm{Te}$ to ${}^{136}\mathrm{I}$. We give a new interpretation of ${}^{136}\mathrm{I}$ and its decay to ${}^{136}\mathrm{Xe}$ in terms of the influence of the neutron $h_{9/2}$ orbital and the Gamow-Teller strength for $N=83$.

Yrast and near-yrast levels up to an $I=17\hslash$ spin value and a 6-MeV excitation energy have been delineated in the “two-neutron” ${}^{210}\mathrm{Pb}$ nucleus following deep-inelastic reactions involving ${}^{208}\mathrm{Pb}$ targets and a number of heavy-ion beams at energies $\sim 25\%$ above the Coulomb barrier. The level scheme was established on the basis of multifold prompt and delayed coincidence relationships measured with the Gammasphere array. In addition to the previously known states, many new levels were identified. For most of the strongly populated states, spin-parity assignments are proposed on the basis of angular distributions. The reinvestigation of the $\nu {\left(g_{9/2}\right)}^2$, $8^{+}$ isomeric decay results in the firm identification of the low-energy $E2$ transitions involved in the $8^{+}\to 6^{+}\to 4^{+}$ cascade, and in a revised $6^{+}$ level half-life of 92(10) ns, nearly a factor of 2 longer than previously measured. Among the newly identified states figure spin $I=4–10\hslash$ levels associated with the $\nu g_{9/2}{i}_{11/2}$ multiplet, as well as yrast states involving $\nu g_{9/2}{j}_{15/2}$, $\nu i_{11/2}{j}_{15/2}$, and $\nu {\left(j_{15/2}\right)}^2$ neutron couplings. The highest-spin excitations are understood as $1p\text{−}1h$ core excitations and the yrast population is found to be fragmented to the extent that levels of spin higher than $I=17\hslash$ could not be reached. Four $E3$ transitions are present in the ${}^{210}\mathrm{Pb}$ yrast decay; three of these involve the $g_{9/2}\to j_{15/2}$ octupole component, as reflected in the 21(2) and $>10$ Weisskopf unit enhancements of the $B\left(E3\right)$ rates of the first two. The fourth, ${16}^{+}\to {13}^{-}E3$ transition corresponds to the $3^{-}$ core octupole excitation built on the $\nu i_{11/2}{j}_{15/2}$ state, in analogy to a similar $E3$ coupling to the $\nu j_{15/2}$ level in ${}^{209}\mathrm{Pb}$. Shell-model calculations performed for two-neutron states and $1p\text{−}1h$ ${}^{208}\mathrm{Pb}$ core excitations are in good agreement with the data. Evidence was found for the existence of a hitherto unknown high-spin $\beta$-decaying isomer in ${}^{210}\mathrm{Tl}$. Shell-model calculations of the ${}^{210}\mathrm{Tl}$ levels suggest the possibility of a ${11}^{+}$ long-lived, $\beta$-decaying state, and the delayed yields observed in various reactions fit rather well with a ${}^{210}\mathrm{Tl}$ assignment.

We investigate resonance states in three-cluster continuum of some light nuclei, ${}^9\mathrm{Be}$, ${}^9\mathrm{B}$, ${}^{10}\mathrm{B}$, ${}^{11}\mathrm{B}$, and ${}^{11}\mathrm{C}$. These nuclei are considered to have a three-cluster configuration consisting of two $\alpha$ particles and a neutron, proton, deuteron, triton, and nucleus ${}^3\mathrm{He}$, respectively. In this study, we make use of two different microscopic three-cluster models. The first model employs the hyperspherical harmonics basis to enumerate channels and describe three-cluster continuum. The second model is the well-known complex scaling method. The nucleon-nucleon interaction is modeled by the semirealistic Minnesota and Hasegawa-Nagata potentials. Our main aim is to find the Hoyle-analog states in these nuclei or, in other words, whether it is possible to synthesize these nuclei in a triple collision of clusters. We formulate the criteria for selecting such states and apply them to resonance states, emerged from our calculations. We found that there are resonance states obeying the formulated criteria which make possible syntheses of these nuclei in a stellar environment.

Background: Statistical models are successfully used to describe particle multiplicities in (ultra)relativistic heavy ion collisions. Transport models usually lack the ability to describe special aspects of the results of these experiments, as the fast equilibration and some multiplicity ratios.

Purpose: An alternative, unorthodox picture of the dynamics of heavy ion collisions is developed using the concept of Hagedorn states.

Method: A prescription of the bootstrap of Hagedorn states respecting the conserved quantum numbers baryon number $B$, strangeness $S$, isospin $I$ is implemented into the GiBUU transport model.

Results: Using a strangeness saturation suppression factor suitable for nucleon-nucleon collisions, recent experimental data for the strangeness production by the HADES collaboration in Au + Au and Ar + KCl is reasonably well described. The experimentally observed exponential slopes of the energy distributions are nicely reproduced.

Conclusions: A dynamical model using Hagedorn resonance states, supplemented by a strangeness saturation suppression factor, is able to explain essential features (multiplicities, exponential slope) of experimental data for strangeness production in nucleus-nucleus collisions close to threshold.

I have estimated the amount of $p\text{−}\mathrm{shell}\to {\left(sd\right)}^2$ core excitation in ${}^{13}\mathrm{B}$ that involves an $sd$-shell proton, and then the spectroscopic factors for proton removal from ${}^{13}\mathrm{B}$ to negative-parity states of ${}^{12}\mathrm{Be}$. Results are $S\sim {10}^{-2}$, indicating that these states are unlikely to be populated in that reaction.

The $n\mathrm{th}$-order linear flow coefficients $v_n^L(n=2,3,4,5)$, and the corresponding nonlinear mode-coupled ($\mathrm{mc}$) coefficients $v_{4,(2,2)}^{\mathrm{mc}}$, $v_{5,(2,3)}^{\mathrm{mc}}$, $v_{6,(3,3)}^{\mathrm{mc}}$, and $v_{6,(2,2,2)}^{\mathrm{mc}}$, are studied for Pb+Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV. Both sets of coefficients indicate a common acoustic scaling pattern of exponential viscous modulation, with a rate proportional to the square of the harmonic numbers and the mean transverse momenta (respectively), and inversely proportional to the cube root of the charged particle multiplicity $\left[{\left(N_{\mathrm{ch}}\right)}^{1/3}\right]$, which characterizes the dimensionless size of the systems produced in the collisions. These patterns and their associated scaling parameters provide new stringent constraints for eccentricity-independent estimates of the specific shear viscosity $\frac{\eta }{s}\left(T\right)$ and the viscous correction to the thermal distribution function for the matter produced in the collisions. They also give crucial constraints for extraction of the initial-state eccentricity spectrum.

The nuclear multiple chirality in $A\approx 60$ mass region is explored by the adiabatic and configuration-fixed constrained covariant density functional theory for cobalt isotopes. The potential-energy curves and triaxiality parameters $\gamma$ as functions of the deformation parameter $\beta$ in ${}^{54,56,57,58,59,60}\mathrm{Co}$ are obtained. It is found that there are high-$j$ particle(s) and hole(s) configurations with prominent triaxially deformed shapes in these isotopes. This points towards that the existence of chirality or multiple chirality in $A\approx 60$ mass region are highly anticipated.

Fine structure in the $\alpha$ decay of high-spin isomers in ${}^{155}\mathrm{Lu}(25/2^{-})$ and ${}^{156}\mathrm{Hf}\left(8^{+}\right)$ has been studied for the first time using $\alpha \gamma$-coincidence analysis. Three new $\alpha$ decays from ${}^{155}\mathrm{Lu}(25/2^{-})$ and two from ${}^{156}\mathrm{Hf}\left(8^{+}\right)$ have been identified, populating seniority $s>1$ states in the $N=82$ nuclei ${}^{151}\mathrm{Tm}$ and ${}^{152}\mathrm{Yb}$, respectively. The reduced hindrance factors of the $\alpha$ decays support the previous configuration assignments of the populated states. This is the first observation of states with excitation energy greater than 1.5 MeV being populated following $\alpha$ decay in nuclei outside of the ${}^{208}\mathrm{Pb}$ region.

We use new high statistics data from CLAS and COMPASS on the nucleon's spin structure function at low Bjorken $x$ and low virtuality, $Q^2<0.5{\mathrm{GeV}}^2$, together with earlier measurements from the SLAC E-143, HERMES, and GDH experiments to estimate the effective intercept(s) for spin dependent Regge theory. We find ${\alpha }_{a_1}=0.31\pm 0.04$ for the intercept describing the high-energy behavior of spin dependent photoabsorption together with a new estimate for the high-energy part of the Gerasimov-Drell-Hearn sum rule: $-15\pm 2\mu \mathrm{b}$ from photon-proton center-of-mass energy greater than 2.5 GeV. Our value of ${\alpha }_{a_1}$ suggests QCD physics beyond a simple straight-line $a_1$ trajectory.

The neutron-proton-electron matter under a strong magnetic field is studied in the context of the covariant Vlasov approach. We use a Walecka-type hadronic model and the dispersion relations for the longitudinal and transverse modes are obtained. The instability regions for longitudinal and transverse modes are also studied. The crust-core transition of a magnetized neutron star is discussed.

Excited states above the ${17}^{+}$ isomeric state in the proton-rich nucleus ${}^{152}\mathrm{Tm}$ were established by employing the recoil-isomer tagging technique. Data were collected using the JUROGAM gamma-ray array and the GREAT spectrometer together with the recoil ion transport unit (RITU) gas-filled recoil separator and analyzed to identify the prompt and delayed $\gamma$ decays from the levels in ${}^{152}\mathrm{Tm}$. Shell-model calculations, either in a large valence space or in a reduced model space with five protons in the $\pi 0h_{11/2}$ orbital and one neutron in the $\nu 1f_{7/2}$ orbital, agree with the observed energies of the yrast levels up to angular momentum $J=21$. The observation of near degeneracies in the energy spectrum can be attributed to specific components of the proton-neutron interaction. The isomeric decay of the ${17}^{+}$ level is not reproduced in the shell-model calculations as it arises from a delicate balance between hindrance due to seniority selection rules and enhancement due to configuration mixing.

The dynamical polarization potential (DPP) generated by the coupling of specific reaction channels to the elastic channel can be determined by inverting the elastic channel $S$ matrix from a coupled reaction channel (CRC) calculation. The “bare” potential of the CRC calculation is then subtracted from the inverted potential to yield a local representation of the DPP. Here we study the extent to which the DPP calculated in this way depends upon the bare potential. We find that the DPP caused by coupling to pickup channels, for 30.3 MeV protons scattering from ${}^{40}\mathrm{Ca}$, turns out to be qualitatively and almost quantitatively unaffected by substantial changes in the bare potential. This puts the properties of DPPs established in this way on a firmer foundation.

The α-decay half-lives of superheavy nuclei are studied using the generalized liquid-drop model (GLDM) with 1977 nuclear proximity potential proposed by Blocki et al. [Ann. Phys. (NY) 105, 427 (1977)]. The result obtained with the present formalism is compared with the experimental half-lives and half-lives using GLDM. The standard deviation of the present approach is found to be 0.34, which is less than that of GLDM of Royer (0.56). The study is extended to predict the α half-lives of some of the unknown isotopes in superheavy region. We hope that the predictions on the α-decay half-lives using the present formalism may be helpful in future investigations in this field.

In heavy-ion fusion reactions, the energy of the projectile couples with the intrinsic degrees of freedom of the target during the collision process and this leads to a dissipative phenomenon. Consequently, the dissipation in the system causes the angular momentum hindrance during the fusion process. In this work, we have focused on the dissipative behavior of the fusing nuclei and its dependency on the incident energy. The dissipative evolution of the system depends not only on the entrance channel mass asymmetry but also on the incident energy, which was not mentioned in earlier studies. Moreover, the dissipative behavior of the fusing nuclei is also compared with respect to the entrance channel parameters like mass asymmetry $\alpha$ and the Coulomb interaction term $Z_P{Z}_T$. The dissipation phenomenon decreases when the mass asymmetry increases and it increases when the Coulomb interaction term $Z_P{Z}_T$ increases.

We present a global analysis of the inclusive quasielastic electron scattering data with a superscaling approach with relativistic effective mass. The SuSAM* model exploits the approximation of factorization of the scaling function $f^{*}\left({\psi }^{*}\right)$ out of the cross section under quasifree conditions. Our approach is based on the relativistic mean field theory of nuclear matter where a relativistic effective mass for the nucleon encodes the dynamics of nucleons moving in presence of scalar and vector potentials. Both the scaling variable ${\psi }^{*}$ and the single nucleon cross sections include the effective mass as a parameter to be fitted to the data alongside the Fermi momentum $k_F$. Several methods to extract the scaling function and its uncertainty from the data are proposed and compared. The model predictions for the quasielastic cross section and the theoretical error bands are presented and discussed for nuclei along the periodic table from $A=2$ to $A=238$: ${}^2\mathrm{H}$, ${}^3\mathrm{H}$, ${}^3\mathrm{He}$, ${}^4\mathrm{He}$, ${}^{12}\mathrm{C}$, ${}^6\mathrm{Li}$, ${}^9\mathrm{Be}$, ${}^{24}\mathrm{Mg}$, ${}^{59}\mathrm{Ni}$, ${}^{89}\mathrm{Y}$, ${}^{119}\mathrm{Sn}$, ${}^{181}\mathrm{Ta}$, ${}^{186}\mathrm{W}$, ${}^{197}\mathrm{Au}$, ${}^{16}\mathrm{O}$, ${}^{27}\mathrm{Al}$, ${}^{40}\mathrm{Ca}$, ${}^{48}\mathrm{Ca}$, ${}^{56}\mathrm{Fe}$, ${}^{208}\mathrm{Pb}$, and ${}^{238}\mathrm{U}$. We find that more than 9 000 of the total $\approx 20000$ data fall within the quasielastic theoretical bands. Predictions for ${}^{48}\mathrm{Ti}$ and ${}^{40}\mathrm{Ar}$ are also provided for the kinematics of interest to neutrino experiments.

In this paper we study charmonium suppression in heavy ion collisions and develop a joint microscopic description of the initial- and final-state interactions. In the cold phase, we consider a conventional mechanism of nuclear suppression due to inelastic absorptive interactions. We also take into account a novel production mechanism via fusion of three gluons from different nucleons, which partially compensates the strong suppression of the first term expected in the Large Hadron Collider (LHC) kinematics. In the hot phase, we take into account both the Debye screening and the absorptive correction due to color-exchange interactions with the medium. We found that the latter mechanism becomes dominant for large transverse momenta $\langle p_T\rangle \gtrsim 10\mathrm{GeV}$. The evaluated suppression $R_{AA}$ in our approach is in reasonable agreement with recent experimental data for $J/\psi$ and $\psi \left(2S\right)$ in the LHC kinematics.