The nucleus-nucleus interaction potentials in heavy-ion fusion reactions are extracted from the microscopic time-dependent Hartree-Fock theory for the mass symmetric reactions ${}^{16}\mathrm{O}\hspace{0.5em}+\hspace{0.5em}{}^{16}\mathrm{O}$, ${}^{40}\mathrm{Ca}\hspace{0.5em}+\hspace{0.5em}{}^{40}\mathrm{Ca}$, and ${}^{48}\mathrm{Ca}\hspace{0.5em}+\hspace{0.5em}{}^{48}\mathrm{Ca}$ and the mass asymmetric reactions ${}^{16}\mathrm{O}\hspace{0.5em}+\hspace{0.5em}{}^{40,\hspace{0.5em}48}\mathrm{Ca}$, ${}^{40}\mathrm{Ca}\hspace{0.5em}+\hspace{0.5em}{}^{48}\mathrm{Ca}$, ${}^{16}\mathrm{O}\hspace{0.5em}+\hspace{0.5em}{}^{208}\mathrm{Pb}$, and ${}^{40}\mathrm{Ca}\hspace{0.5em}+\hspace{0.5em}{}^{90}\mathrm{Zr}$. When the c.m. energy is much higher than the Coulomb barrier energy, potentials deduced with the microscopic theory identify with the frozen density approximation. As the c.m. energy decreases and approaches the Coulomb barrier, potentials become energy dependent. This dependence indicates dynamical reorganization of internal degrees of freedom and leads to a reduction of the “apparent” barrier felt by the two nuclei during fusion of the order of 2–3% compared to the frozen density case. Several examples illustrate that the potential landscape changes rapidly when the c.m. energy is in the vicinity of the Coulomb barrier energy. The energy dependence is expected to have a significant role on fusion around the Coulomb barrier.

The continuum discretized coupled channels (CDCC) approach is applied to analysis of deuteron elastic scattering from ${}^{6,7}\mathrm{Li}$ in the energy range from 10 to 50 MeV. Phenomenological neutron and proton optical potentials that are essentially important in the CDCC calculation are determined from the present optical model analysis of differential cross sections of nucleon elastic scattering, neutron total cross sections, and reaction cross sections of ${}^{6,7}\mathrm{Li}$ for energies from 5 to 50 MeV. The CDCC result provides satisfactory agreement with experimental data, particularly at forward angles. The obtained nucleon optical model potentials are found to describe reasonably well both nucleon and deuteron elastic scattering from ${}^{6,7}\mathrm{Li}$ for energies up to 50 MeV.

The collisions in four different reaction systems using ${}^{40,48}\mathrm{Ca}$ and ${}^{58,64}\mathrm{Ni}$ isotope beams and a Be target have been simulated using the heavy ion phase space exploration and the antisymmetrized molecular dynamics models. The present study mainly focuses on the model predictions for the excitation energies of the hot fragments and the cross sections of the final fragments produced in these reactions. The effects of various factors influencing the final fragment cross sections, such as the choice of the statistical decay code and its parameters, have been explored. The predicted fragment cross sections are compared to the projectile fragmentation cross sections measured with the A1900 mass separator. At $E/A=140$ MeV, reaction dynamics can significantly modify the detection efficiencies for the fragments and make them different from the efficiencies applied to the measured data reported in the previous work. The effects of efficiency corrections on the validation of event generator codes are discussed in the context of the two models.

The production cross sections of neutron-rich isotopes of Mg, Al, Si, P, S, Cl, Ar, K, Ca, Sc, and Ti in the multinucleon transfer reactions ${}^{48}\mathrm{Ca}(64\hspace{0.5em}\mathrm{MeV}/\mathrm{nucleon},\hspace{0.5em}140\hspace{0.5em}\mathrm{MeV}/\mathrm{nucleon})\hspace{0.5em}+\hspace{0.5em}{}^{181}\mathrm{Ta}$ and ${}^{48}\mathrm{Ca}(142\hspace{0.5em}\mathrm{MeV}/\mathrm{nucleon})\hspace{0.5em}+\hspace{0.5em}{}^{\mathrm{nat}}\mathrm{W}$ are estimated. A good agreement of the calculated results with the available experimental data confirms the mechanism of multinucleon transfer at almost peripheral collisions at intermediate energies. The global trend of production cross section with the charge (mass) number of target in reactions with ${}^{48}\mathrm{Ca}$ beam is discussed for the future experiments.

Target mass corrections to the twist-4 terms ${\tilde{f}}_2^{p,n,d}$ as well as to the leading-twist ${\tilde{a}}_2$ are discussed.

The low-energy scattering of two charged particles is analyzed using a renormalization group approach based on dimensional regularization with power-divergence subtraction. A nontrivial solution with a marginally unstable direction is found, corresponding to a system with a bound state at zero energy. For purely energy-dependent perturbations around this solution, the power counting agrees with that from Wilsonian methods. These terms in the effective potential are in direct correspondence with the the terms in the Coulomb-distorted effective-range expansion. We also study perturbations that depend on off-shell momenta as well as energy, and we show that these affect only the off-shell form of the scattering matrix. These terms are of higher order than the corresponding energy-dependent ones and so terms in the potential that depend only on the off-shell momenta do not have definite orders in power counting.

The bare nucleon-nucleon interaction is essential for the production of pair correlations in nuclei, but an important contribution also arises from the induced interaction resulting from the exchange of collective vibrations between nucleons moving in time reversal states close to the Fermi energy. The pairing field resulting from the summed interaction is strongly peaked at the nuclear surface. It is possible to reproduce the detailed spatial dependence of this field by using either a local approximation, which fully takes into account finite size effects, or a contact interaction, with parameters that are quite different from those commonly used in more phenomenological approaches.

The cross sections and analyzing powers for $(p,n)$ reactions on ${}^3\mathrm{He}$ and ${}^4\mathrm{He}$ have been measured at a bombarding energy of $T_p=346$ MeV and reaction angles of ${\theta }_{\mathrm{lab}}=9.4^{°}\text{−}{27}^{°}$. The energy transfer spectra for ${}^3\mathrm{He}(p,n)$ at large ${\theta }_{\mathrm{lab}}$ ($⩾{16}^{°}$) are dominated by quasielastic contributions and can be reasonably reproduced by plane-wave impulse approximation (PWIA) calculations for quasielastic scattering. By contrast, the known $L=1$ resonances in ${}^4\mathrm{Li}$ are clearly observed near the threshold in the ${}^4\mathrm{He}(p,n)$ spectra. Because these contributions are remarkable at small angles, the energy spectra are significantly different from those expected for quasielastic scattering. The data are compared with the PWIA calculations, and it is found that the quasielastic contributions are dominant at large ${\theta }_{\mathrm{lab}}$ ($⩾{22}^{°}$). The nuclear correlation effects on the quasielastic peak for ${}^4\mathrm{He}(p,n)$ are also discussed.

Straight line trajectories are commonly used in semiclassical calculations of the first-order Coulomb excitation cross section at intermediate energies, and simple corrections are often made for the distortion of the trajectories that is caused by the Coulomb field. These approximations are tested by comparing to numerical calculations that use exact Coulomb trajectories. In this paper a model is devised for including relativistic effects in the calculations. It converges at high energies toward the relativistic straight-line trajectory approximation and approaches the non-relativistic Coulomb trajectory calculation at low energies. The model is tested against a number of measurements and analyses that have been performed at beam energies between 30 and 70 MeV/nucleon, primarily of quadrupole excitations. Remarkably good agreement is achieved with the previous analyses, and good agreement is also achieved in the few cases, where the $B$($E\lambda$) value is known from other methods. The magnitudes of the relativistic and Coulomb distortion effects are discussed.

Pre-scission neutron multiplicities are measured for ${}^{12}\mathrm{C}\hspace{0.5em}+\hspace{0.5em}{}^{204}\mathrm{Pb}$ and ${}^{19}\mathrm{F}\hspace{0.5em}+\hspace{0.5em}{}^{197}\mathrm{Au}$ reactions at laboratory energies of 75–95 MeV for the ${}^{12}\mathrm{C}$ beam and 98–118 MeV for the ${}^{19}\mathrm{F}$ beam. The chosen projectile-target combinations in the present study lie on either side of the Businaro-Gallone mass asymmetry (${\alpha }_{\mathrm{BG}}$) and populate the ${}^{216}\mathrm{Ra}$ compound nucleus. The dissipation strength is deduced after comparing the experimentally measured neutron yield with the statistical model predictions which contains the nuclear viscosity as a free parameter. Present results demonstrate the combined effects of entrance channel mass asymmetry and the dissipative property of nuclear matter on the pre-scission neutron multiplicity in fusion-fission reactions.

One of the most surprising results is to find that a consistent description of all the experimental results on particle multiplicities and ratios obtained from the lowest Alternating Gradient Synchrotron to the highest Relativistic Heavy Ion Collider energies is possible within the framework of a thermal statistical model. We explore here the utility of a thermodynamically consistent excluded volume model recently proposed by us in explaining the above experimental results and we further compare our results with those obtained from an ideal gas model and other excluded-volume model that are often used in describing a grand canonical statistical system consisting of hot, dense hadron gas. We find that the energy dependence of the total multiplicities of strange and nonstrange hadrons in general shows close agreement with the experimental data, although slight deviation is observed for some multistrange hadrons, e.g., $\Omega +\overline{\Omega },\Xi$, and Φ. The difference observed in these cases does not clearly support our assumption of the same freeze-out volume of the fireball that homogeneously emit all kinds of particles. Similarly we have calculated the ratios for particles and antiparticles such as $K^{-}/K^{+},\overline{p}/p,\overline{\Lambda }/\Lambda ,\overline{\Xi }/\Xi$, and $\overline{\Omega }/\Omega$, as well as the ratios of the unequal mass particles $\langle K^{+}\rangle /\langle {\pi }^{+}\rangle ,\langle K^{-}\rangle /\langle {\pi }^{-}\rangle ,\hspace{0.5em}\langle \Lambda \rangle /\langle \pi \rangle ,\langle {\Xi }^{-}\rangle /\langle \pi \rangle ,\langle \Omega +\overline{\Omega }\rangle /\langle \pi \rangle$, and $\langle \Phi \rangle /\langle \pi \rangle$ and studied their variations with respect to the center-of-mass energy in the excluded-volume models and, finally, the results are compared with the experimental data. We find that in some cases, although the calculated results show close agreements with the experimental data, the deviations between theory and experiment in cases of unequal mass and multistrange particle ratios, like $\langle \Lambda \rangle /\langle \pi \rangle ,\langle {\Xi }^{-}\rangle /\langle \pi \rangle ,\langle \Omega +\overline{\Omega }\rangle /\langle \pi \rangle ,\langle \Phi \rangle /\langle \pi \rangle ,$ etc., appear to be quite large and thus warrant further investigations on the suitability of thermal hadron gas models.

Based on the rainbow-ladder approximation of the Dyson-Schwinger equations and the assumption of the analyticity of the quark-meson vertex in the neighborhood of zero chemical potential ($\mu =0$) and neglecting the μ-dependence of the dressed gluon propagator, we use the method of studying the dressed quark propagator at finite chemical potential given in [H. S. Zong, L. Chang, F.Y. Hou, W. M. Sun, and Y. X. Liu, Phys. Rev. C 71, 015205 (2005)] to show that the axial-vector quark-meson vertex at finite μ can be obtained from the corresponding one at $\mu =0$ by a shift of variable: ${\Gamma }_{5\nu }^j[\mu ](k,\hspace{0.5em}p)={\Gamma }_{5\nu }^j(\tilde{k},\hspace{0.5em}p)$, where $k$ and $p$ are the relative and total momentum of the quark-antiquark pair, respectively, and $\tilde{k}=(\overrightarrow{k},\hspace{0.5em}{k}_4+i\mu )$. Similar relations hold for any other type of quark-meson vertex. This feature would facilitate the numerical calculations of the quark-meson vertex function at finite μ considerably. Based on these results and using the dressed quark propagator at $\mu =0$ proposed in [R. Alkofer, W. Detmold, C. S. Fischer, and P. Maris, Phys. Rev. D 70, 014014 (2004)], we calculate the pion decay constant $f_{\pi }$ and the pion mass $m_{\pi }$ at finite μ and a comparison of our results with those in the literature is made.

The effect of neutrino trapping on the longitudinal dielectric function at low densities has been investigated by using different relativistic mean-field models. Parameter sets G2 of Furnstahl-Serot-Tang and Z271 of Horowitz-Piekarewicz, along with the adjusted parameter sets of both models, have been used in this study. The role of the isovector adjustment and the effect of the Coulomb interaction have also been studied. The effect of the isovector adjustment is found to be more significant in the Horowitz-Piekarewicz model, not only in neutrinoless matter but also in matter with neutrino trapping. Although almost independent to the variation of the leptonic fraction, the instability region of matter with neutrino trapping is found to be larger. The presence of more protons and electrons compared to the neutrinoless case is the reason behind this finding. For parameter sets with soft equations of state at low density, the appearance of a large and negative ${\varepsilon }_L(q,q_0=0)$ in some parts of the edge of the instability region in matter with neutrino trapping is understood as a consequence of the fact that the Coulomb interaction produced by electron and proton interaction is larger than the repulsive isovector interaction created by the asymmetry between the proton and neutron numbers.

A comparison of various thermometric techniques used for the estimation of nuclear temperature has been made from the decay of hot composite ${}^{32}{\mathrm{S}}^{*}$ produced in the reaction ${}^{20}\mathrm{Ne}\hspace{0.5em}(145\hspace{0.5em}\mathrm{MeV})\hspace{0.5em}+\hspace{0.5em}{}^{12}\mathrm{C}$. It is shown that the temperatures estimated by different techniques, known to vary significantly in the Fermi energy domain, are consistent with each other within experimental limits for the system studied here.

The effect of dipole polarizability (${\alpha }_0$) of ${}^7\mathrm{Li}$ due to its cluster structure has been determined from a high precision elastic scattering measurement of ${}^7\mathrm{Li}$ on ${}^{208}\mathrm{Pb}$, over a range of energies from $E_{\mathrm{lab}}=18\text{−}28\hspace{0.5em}\mathrm{MeV}(V_{\mathrm{Coul}}\approx 30\hspace{0.5em}\mathrm{MeV})$. Continuum discretized coupled channel (CDCC) calculations have been performed to describe the measured elastic scattering data.

We propose a low energy effective field theory of QCD at the scale of pion mass for the $N_B=2$ sector, $N_B$ being the baryon number, which contains two dibaryon fields in addition to the nucleons and pions. It has a well-defined counting is renormalizable, and the nucleon-nucleon scattering amplitudes are manifestly unitary at leading order. We work out a lower energy effective theory for nucleons with energy much lower than the pion mass and three-momentum comparable to it, which also has a well-defined counting and is renormalizable. The dibaryon fields must also be kept as explicit degrees of freedom in this theory. We calculate the scattering amplitudes at next-to-leading order for the ${}^1{S}_0$ and ${}^3{S}_1$ channels in this framework and obtain an excellent description of the phase shifts for center-of-mass energies in the 0–50 MeV range.

Two heavy-ion induced fusion reactions producing ${}^{261,262}\mathrm{Bh}$ were studied using the Berkeley Gas-filled Separator at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. An excitation function for the production of ${}^{262}\mathrm{Bh}$ via the reaction ${}^{209}\mathrm{Bi}({}^{54}\mathrm{Cr},n){}^{262}\mathrm{Bh}$ was measured with a maximum cross section from a fit to the data of 430 ± 110 pb observed at a compound nucleus excitation energy of 15.7 MeV. New data have been measured for the 1$n$ exit channel of the ${}^{208}\mathrm{Pb}({}^{55}\mathrm{Mn},\hspace{0.5em}n){}^{262}\mathrm{Bh}$ reaction. We present an updated excitation function with an observed maximum cross section of $530\pm 100$ pb at a compound nucleus excitation energy of 14.1 MeV. Events corresponding to the 2$n$ exit channel for the ${}^{209}\mathrm{Bi}({}^{54}\mathrm{Cr},2n){}^{261}\mathrm{Bh}$ and ${}^{208}\mathrm{Pb}({}^{55}\mathrm{Mn},2n){}^{261}\mathrm{Bh}$ reactions were also observed and are presented as partial excitation functions. The measured decay properties correspond well with existing experimental data. We compare these experimental results to cross section predictions from a model by Świa˛tecki et al. and discuss entrance channel effects on the magnitude of 1$n$ cross sections.