The influence of angular momentum on the competition between complete fusion followed by the decay of compound nucleus and quasifission channels is treated within the dinuclear system model. The charge distributions of the products in the reactions ${}^{28}\mathrm{Si}$$+$${}^{96}\mathrm{Zr}$, ${}^4\mathrm{He}$$+$${}^{130}\mathrm{Te}$, and ${}^{40}\mathrm{Ca}$$+$${}^{82}\mathrm{Kr}$ are predicted at bombarding energies above the Coulomb barrier. The results of calculations for the reactions ${}^{93}\mathrm{Nb}$$+$${}^9\mathrm{Be}$,${}^{12}\mathrm{C}$,${}^{27}\mathrm{Al}$; ${}^{84}\mathrm{Kr}$$+$${}^{27}\mathrm{Al}$; ${}^{86}\mathrm{Kr}$$+$${}^{63}\mathrm{Cu}$; ${}^{139}\mathrm{La}$$+$${}^{12}\mathrm{C}$,${}^{27}\mathrm{Al}$; and ${}^{45}\mathrm{Sc}$$+$${}^{65}\mathrm{Cu}$ are compared with the available experimental data.

The effects of an external magnetic field on the nuclear medium are studied within the Skyrme model of the nuclear interaction. The equation of state, spin polarization, and magnetization are evaluated at zero temperature for both neutron matter and isospin symmetric nuclear matter. We consider the anomalous magnetic moments of the nucleons and the quantization induced by a magnetic field over the proton energy spectrum. A comparison of two versions of the model, allowing or not for spontaneous magnetization, is performed. We cover a range of magnetic-field strengths and matter densities appropriate for astrophysical studies.

Using a contraction of the SU(3) algebra to the algebra of the rigid rotator in the large-boson-number limit of the interacting boson approximation (IBA) model, a line is found inside the symmetry triangle of the IBA, along which the SU(3) symmetry is preserved. The line extends from the SU(3) vertex to near the critical line of the first-order shape/phase transition separating the spherical and prolate deformed phases, and it lies within the Alhassid-Whelan arc of regularity, the unique valley of regularity connecting the SU(3) and U(5) vertices in the midst of chaotic regions. In addition to providing an explanation for the existence of the arc of regularity, the present line represents an example of an analytically determined approximate symmetry in the interior of the symmetry triangle of the IBA. The method is applicable to algebraic models possessing subalgebras amenable to contraction. This condition is equivalent to algebras in which the equilibrium ground state and its rotational band become energetically isolated from intrinsic excitations, as typified by deformed solutions to the IBA for large numbers of valence nucleons.

We use known widths and branching ratios in ${}^{11}\mathrm{Be}$ to discuss $J^{\mathrm{\pi }}$ and configuration admixtures. Analysis favors 3/$2^{-}$ for the 3.96-MeV state and three-state mixing for this $J^{\mathrm{\pi }}$.

The heaviest isotopes of elements $Z=117$ to $Z=105$, ${}^{294}117$, ${}^{293}117$, ${}^{290}115$, ${}^{289}115$, ${}^{286}113$, ${}^{285}113$, ${}^{282}\mathrm{Rg}$, ${}^{281}\mathrm{Rg}$, ${}^{278}\mathrm{Mt}$, ${}^{274}\mathrm{Bh}$, and ${}^{270}\mathrm{Db}$, were identified by means of the Dubna gas-filled recoil separator among the products of the ${}^{249}\mathrm{Bk}$ $+$ ${}^{48}\mathrm{Ca}$ reaction. The details of the observed six decay chains, indicating the production and decay of isotopes ${}^{293}117$ and ${}^{294}117$, are presented and discussed. The decay energies and resulting half-lives of these new nuclei show a strong rise of stability with increasing neutron number, validating the concept of the island of enhanced stability for superheavy nuclei [Oganessian et al., Phys. Rev. Lett. 104, 142502 (2010)].

The intrinsic excitation energy of fission fragments is dynamically evaluated in terms of the time-dependent pairing equations. These equations are corroborated with two conditions. One of them fixes the number of particles and the other separates the pairing active spaces associated to the two fragments in the vicinity of the scission configuration. The fission path is obtained in the frame of the macroscopic-microscopic model. The single-particle-level schemes are obtained within the two-center Woods-Saxon shell model. It is shown that the available intrinsic dissipated energy is not shared proportionally to the masses of the two fission fragments. If the heavy fragment possesses nucleon numbers close to the magic ones, the accumulated intrinsic excitation energy is lower than that of the light fragment.

The critical phenomenon of the liquid-gas phase transition has been investigated in the reactions ${}^{78,86}\mathrm{Kr}$$+$${}^{58,64}\mathrm{Ni}$ at beam energy of 35 MeV/nucleon using the Landau free energy approach with isospin asymmetry as an order parameter. Fits to the free energy of fragments showed three minima, suggesting that the system is in the regime of a first-order phase transition. The relation m $=$ −∂F/∂H, which defines the order parameter and its conjugate field $H$, has been experimentally verified from the linear dependence of the mirror nuclei yield ratio data on the isospin asymmetry of the source. The slope parameter, which is a measure of the distance from a critical temperature, showed a systematic decrease with increasing excitation energy of the source. Within the framework of the Landau free energy approach, isoscaling provided similar results as obtained from the analysis of mirror nuclei yield ratio data. In the present work, it is shown that the external field is primarily related to the minimum of the free energy, which implies a modification of the source concentration Δ used in isospin studies.

We have analyzed pion-nucleon scattering using the manifestly relativistic covariant framework of infrared regularization up to $\mathcal{O}(q^3)$ in the chiral expansion, where $q$ is a generic small momentum. We describe the low-energy phase shifts with a similar quality as previously achieved with heavy baryon chiral perturbation theory, $\sqrt{s}\lesssim 1.14$ GeV. New values are provided for the $\mathcal{O}(q^2)$ and $\mathcal{O}(q^3)$ low-energy constants, which are compared with previous determinations. This is also the case for the scattering lengths and volumes. Finally, we have unitarized the previous amplitudes and as a result the energy range where data are reproduced increases significantly.

We derive a zero-range pseudopotential that includes all possible terms up to sixth order in derivatives. Within the Hartree-Fock approximation, it gives the average energy that corresponds to a quasilocal nuclear energy density functional (EDF) built of derivatives of the one-body density matrix up to sixth order. The direct reference of the EDF to the pseudopotential acts as a constraint that divides the number of independent coupling constants of the EDF by two. This allows, e.g., for expressing the isovector part of the functional in terms of the isoscalar part, or vice versa. We also derive the analogous set of constraints for the coupling constants of the EDF that is restricted by spherical, space-inversion, and time-reversal symmetries.

A decay spectroscopic study of the neutron-rich isotopes has been performed using fragmentation of a ${}^{86}\mathrm{Kr}$ primary beam. Fragments from this reaction have been selected by the LISE2000 spectrometer at the Grand Accélérateur National d’Ions Lourds (GANIL). Half-lives of 29 isotopes, including the first ones identified for ${}^{61}\mathrm{Ti}$ ($15\pm 4$ ms), ${}^{64}\mathrm{V}$ ($19\pm 8$ ms), and ${}^{71}\mathrm{Fe}$ ($28\pm 5$ ms), have been determined and compared with model predictions. ${}^{67,68}\mathrm{Mn}$ $\beta$-delayed $\gamma$ rays were observed for the first time. The branching for the $\beta$-delayed neutron emission was measured to be greater than $10(5)\%$ in the ${}^{67}\mathrm{Mn}$ decay. The ${}^{67}\mathrm{Fe}$ isomeric level is firmly determined at higher energy than assigned in previous works. The excitation energies of the first ($2^{+}$) and ($4^{+}$) states of ${}^{68}\mathrm{Fe}$ are suggested to lie at $522(1)$ and $1389(1)$ keV, respectively, thus bringing confirmation of assignments based on in-beam $\gamma$-ray spectroscopy. Beyond-mean-field calculations with the Gogny D1S force have been performed for even-mass nuclei through the Fe isotopic chain. Not only ${}^{68}\mathrm{Fe}$ but most of the neutron-rich Fe isotopes with neutron numbers below $N=50$ are interpreted as soft rotors. The calculated mean occupancy of the neutron $g_{9/2}$ and $d_{5/2}$ orbitals in correlated ground states is steadily growing with increasing neutron number throughout the isotopic chain. Interpretation of ${}^{67}\mathrm{Fe}$ data is based upon the present calculations for the ${}^{66}\mathrm{Fe}$ and ${}^{68}\mathrm{Fe}$ even cores.

We study high-energy photodisintegration of the deuteron into two $\Delta$ isobars at large center of mass angles within the QCD hard rescattering model (HRM). According to the HRM, the process develops in three main steps: the photon knocks a quark from one of the nucleons in the deuteron; the struck quark rescatters off a quark from the other nucleon sharing the high energy of the photon; then the energetic quarks recombine into two outgoing baryons which have large transverse momenta. Within the HRM, the cross section is expressed through the amplitude of $\mathit{pn}\to \Delta \Delta$ scattering which we evaluated based on the quark-interchange model of hard hadronic scattering. Calculations show that the angular distribution and the strength of the photodisintegration is mainly determined by the properties of the $\mathit{pn}\to \Delta \Delta$ scattering. We predict that the cross section of the deuteron breakup to ${\Delta }^{++}{\Delta }^{-}$ is 4–5 times larger than that of the breakup to the ${\Delta }^{+}{\Delta }^0$ channel. Also, the angular distributions for these two channels are markedly different. These can be compared with the predictions based on the assumption that two hard $\Delta$ isobars are the result of the disintegration of the preexisting $\Delta \Delta$ components of the deuteron wave function. In this case, one expects the angular distributions and cross sections of the breakup in both ${\Delta }^{++}{\Delta }^{-}$ and ${\Delta }^{+}{\Delta }^0$ channels to be similar.

Measurements on multinucleon transfer reactions for ${}^{28}\mathrm{Si}+{}^{90,94}\mathrm{Zr}$ systems were performed at sub- and near-barrier energies. The fact that ${}^{90}\mathrm{Zr}$ has a closed neutron shell ($N$ $=$ 50) and ${}^{94}\mathrm{Zr}$ has four neutrons outside the closed shell, allows us to investigate the effects of shell closure and pairing correlation on multinucleon transfer mechanism. The experiment was performed with pulsed ${}^{28}\mathrm{Si}$ beam using the Heavy Ion Reaction Analyzer (HIRA) at Inter University Accelerator Centre (IUAC), New Delhi. Based on the $Q$-value considerations, it turned out that pickup channels were neutron transfer whereas stripping channels were proton transfer. For the ${}^{28}\mathrm{Si}+{}^{90}\mathrm{Zr}$ system, the values of the slope parameter for two-neutron pickup turned out to be less than that for one-neutron pickup. The values of the slope parameter were almost the same for two-, three-, and four-neutron pickup channels in the case of the ${}^{28}\mathrm{Si}+{}^{94}\mathrm{Zr}$ system. The transfer probabilities in the case of the ${}^{28}\mathrm{Si}+{}^{94}\mathrm{Zr}$ system were much larger than those for the ${}^{28}\mathrm{Si}+{}^{90}\mathrm{Zr}$ system, further supporting the fact that there is a correlation between the transfer channels and sub-barrier fusion cross-section enhancement. An odd-even staggering was observed in the extracted transfer probabilities at the barrier radius implying the role of pairing correlation in transfer reactions.

Event-by-event fluctuations of the chemical composition of the hadronic final state of relativistic heavy-ion collisions carry valuable information on the properties of strongly interacting matter produced in the collisions. However, in experiments incomplete particle identification distorts the observed fluctuation signals. The effect is quantitatively studied and a new technique for measuring chemical fluctuations, the identity method, is proposed. The method fully eliminates the effect of incomplete particle identification. The application of the identity method to experimental data is explained.

The backbending phenomenon in ${}^{48}\mathrm{Cr}$ has been investigated using the recently developed projected configuration interaction (PCI) method, in which the deformed intrinsic states are directly associated with shell model wave functions. Two previous explanations, (i) $K=0$ band crossing and (ii) $K=2$ band crossing, have been reinvestigated using PCI, and it was found that both explanations can successfully reproduce the experimental backbending. The PCI wave functions in the pictures of $K=0$ band crossing and $K=2$ band crossing are highly overlapped. We conclude that there are no unique intrinsic states associated with the yrast states after backbending in ${}^{48}\mathrm{Cr}$.

$\gamma$ rays were measured at several angles in both singles and coincidence modes in the ${}^{115}\mathrm{Sn}$$(\alpha ,n\gamma ){}^{118}$Te reaction at 15 MeV on a thick target. Multipolarities and mixing ratios were determined from the $\gamma$-ray angular distribution analysis. Lifetimes of 11 low- and medium-spin excited states in ${}^{118}\mathrm{Te}$ were determined from a Monte Carlo Doppler-shift attenuation method analysis of the Doppler broadened line shapes of $\gamma$ rays deexciting the levels. The results are discussed in comparison with the predictions of the interacting boson model.

The momentum correlation between protons and $\Lambda$ particles emitted from central Pb$+$Pb collisions at $\sqrt{s_{\mathit{NN}}}=17.3$ GeV was studied by the NA49 experiment at the CERN Super Proton Synchrotron. A clear enhancement is observed for small relative momenta ($q_{\text{inv}}<0.2$ GeV). By fitting a theoretical model, which uses the strong interaction between the proton and the $\Lambda$ in a given pair, to the measured data, a value for the effective source size is deduced. Assuming a static Gaussian source distribution, we derive an effective radius parameter of $R_G=3.02\pm 0.20$(stat.)${}_{-0.16}^{+0.44}$(syst.) fm.

The six-level sequence deduced for the odd-odd nucleus ${}^{156}\mathrm{Pm}$ in the high-spin studies following spontaneous fission of ${}^{252}\mathrm{Cf}$ is shown to constitute the $K^{\pi }=4^{+}$ yrast band having the two-quasiparticle configuration {$p$:5/2[532] $+$ $n$:3/2[521]}. Spin parities $I^{\pi }=4^{+}$ through 9${}^{+}$ are assigned to the earlier suggested six levels. The location and the decay $\gamma$’s of the 10${}^{+}$ level of this band are indicated. It is also pointed out that there are no $\gamma$ rays common to these postfission high-spin spectra and those seen in the ${}^{156}\mathrm{Nd}$ $\beta$-decay studies.

We describe a procedure to improve the nuclear mass predictions obtained by means of the Garvey-Kelson iterative process. This is achieved by reducing the degrees of freedom involved in the process, expressing the Garvey-Kelson relations in terms of one-neutron and one-proton separation energies, and using a theoretical estimation for them. This approach has the effect that the intrinsic error associated with the iterative process grows significantly more slowly. This leads to a better quality of nuclear mass predictions and therefore extends the range for which the predictions are accurate. We test these ideas using different mass models.

Spectra of outgoing neutrons and protons from the ${}^6\mathrm{Li}$ $+$ ${}^{55}\mathrm{Mn}$ reaction and protons from the $\alpha$ $+$ ${}^{57}\mathrm{Fe}$ reaction have been measured with beams of 15-MeV ${}^6\mathrm{Li}$ ions and 30-MeV $\alpha$ particles. These reactions proceed through the same ${}^{61}\mathrm{Ni}$ nucleus at the same excitation energy, thus allowing the difference in reaction mechanisms to be studied. It is shown that spectra from the first reaction measured at backward angles are due to emission from a traditional compound nucleus reaction, in which the intermediate nucleus has reached statistical equilibrium; the spectra from the second reaction contain a significant fraction of pre-equilibrium emission at all angles. Level density parameters of the residual nucleus ${}^{60}\mathrm{Co}$ have been obtained from the first reaction. Both emission spectra and angular distributions have been measured for the second reaction. It was found that the pre-equilibrium component exhibits a forward-peaked angular distribution, as expected, but with a steeper slope than predicted and with an unusual slight rise at angles above ${120}^{°}$. The backward-angle rise is explained qualitatively by the dominance of the multistep compound mechanism at backward angles.

The transverse electron scattering response function of ${}^3\mathrm{He}$ was recently studied by us in the quasielastic peak region for momentum transfers $q$ between 500 and 700 MeV/$c$. Those results, obtained using the active nucleon Breit (ANB) frame, are here supplemented by calculations in the laboratory, Breit, and ANB frames using the two-fragment model discussed in our earlier work on the frame dependence of the longitudinal response function $R_L(q,\omega )$. We find relatively frame-independent results and good agreement with experiment especially for the lower momentum transfers. This agreement occurs when we neglect an $\omega$-dependent piece of the one-body current relativistic correction. Inclusion of this term leads, however, to a rather pronounced frame dependence at $q=700$ MeV/$c$. A discussion of this term is given here. This report also includes a correction to our previous ANB results for $R_T(q,\omega )$.