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We present a parametrization and two fits to proton nucleus scattering data from 20 to 1040 MeV and mass ranges from $^{4}\mathrm{He}$ to $^{208}\mathrm{Pb}$. We show that $^{4}\mathrm{He}$ can be included with the other nuclei instead of having to be treated separately as previously [B. C. Clark, E. D. Cooper, and S. Hama, Phys. Rev. C 73, 024608 (2006)]. An interesting change of sign in the imaginary potentials at low energies and high densities is noted. This may be an indicator of density dependence in the relativistic $g$ matrix.

We present global Dirac optical model fits to elastic proton scattering data from heavy nuclear targets at energies between 65 and 1040 MeV. Such optical potentials provide critical input for a wide variety of nuclear reactions. The energy and mass number dependence of the parameters in the Lorentz four-vector and scalar potentials of Dirac phenomenology are given. The characteristic features of the potentials are discussed and the predictive power of the global approach presented here is tested for both interpolation and extrapolation.

Comparisons are made between results of calculations for intermediate energy nucleon-nucleus scattering for 12C, 16O, 40Ca, 90Zr, and 208Pb, using optical potentials obtained from global Dirac phenomenology and from a microscopic Schr\"odinger model. Differential cross sections and spin observables for scattering from the set of five nuclei at 65 MeV and 200 MeV have been studied to assess the relative merits of each approach. Total reaction cross sections from proton-nucleus and total cross sections from neutron-nucleus scattering have been evaluated and compared with data for those five targets in the energy range 20 MeV to 800 MeV. The methods of analyses give results that compare well with experimental data in those energy regimes for which the procedures are suited., Comment: 22 pages, 12 figures

We derive a stability condition for the Thomas-Fermi solution of a finite nucleus where the underlying force has a finite range. The stability condition can be cast in the form of an eigenvalue equation; these eigenvalues must be all positive. The lowest eigenmodes correspond closely to vibration modes. The relationship of this time-independent formulation to the time-dependent Vlasov equation with self-consistent potential is established.

Differential cross sections for proton elastic scattering from $^{42}$,44,48Ca have been measured at seven energies in the laboratory energy range from 21.0 to 48.4 MeV, and for $^{40}\mathrm{Ca}$ at six energies between 25.0 and 45.0 MeV. Measurements were made at 2.5\ifmmode^\circ\else\textdegree\fi{} intervals from 10\ifmmode^\circ\else\textdegree\fi{} to 90\ifmmode^\circ\else\textdegree\fi{} (laboratory angles), and at 5.0\ifmmode^\circ\else\textdegree\fi{} intervals between 90\ifmmode^\circ\else\textdegree\fi{} and 170\ifmmode^\circ\else\textdegree\fi{}. Relative errors in the data are typically between 3% and 4%; the scale errors are also 3%. The data have been analyzed by both nonrelativistic and relativistic optical models. The optical potential parameters were used to calculate nuclear matter radius information for the calcium isotopic series, which is compared to previous results.

A new way of dealing with the unwanted high momentum components in low energy pion-nucleus optical potentials is presented. The method is developed strictly in accordance with a principle of “smoothness” which has been found very helpful in other contexts of nuclear physics. The effect of taking a standard optical potential and “smoothing” it is small for the pion elastic scattering cross section but large for the pion wavefunction in the nuclear interior. This has the dramatic and much needed effect of lowering the (p,π) differential cross section by an order of magnitude because this reaction is sensitive to the high momentum components of the wavefunction.

We carry out final state hadronic interaction corrections to two body decays ofD0-meson. We demonstrate that the ratio\({{\Gamma \left( {D^0 \to K^ - \pi ^ + } \right)} \mathord{\left/ {\vphantom {{\Gamma \left( {D^0 \to K^ - \pi ^ + } \right)} {\Gamma \left( {D^0 \to \bar K^0 \pi ^0 } \right)}}} \right. \kern-\nulldelimiterspace} {\Gamma \left( {D^0 \to \bar K^0 \pi ^0 } \right)}}\) can be very different from the free quark and the hard gluon corrected schemes. We also discuss Γ(D0→K+K−)/Γ(D0→π+π−) treating the ππ and theK\(\bar K\) systems as coupled channels.

Presented here is an algorithm tailored to solve the radial Schrodinger equation for the case of proton scattering from an optical potential. The algorithm is straightforward to use and results in a significant increase in speed, around a factor of 2 at least, over the conventional Numerov algorithm.

The amplitude for the ( p,..pi../sup +/) reaction is calculated in a relativistic one-nucleon model with use of a distorted-wave Born-approximation approach. The nucleon continuum and bound-state wave functions are solutions of Dirac equations with appropriate vector and scalar nuclear potentials. Calculations with the pseudovector ..pi..NN coupling, which satisfies the constraints of partial conservation of the axial-vector current, are in much better agreement with the data than calculations with the simple pseudoscalar coupling.

We present a global relativistic optical model for p+40Ca consisting of Lorentz scalar and vector potentials parametrized as a function of energy. The shapes chosen are Woods-Saxons for the real potentials, and a linear combination of Woods-Saxons and derivative Woods-Saxons for the imaginary potentials.

The diffusivity of the nuclear surface plays an important role in peripherial collisions between two heavy ions. We show that a finite range force produces a diffuse surface for static nuclei in the Vlasov prescription. The surface is calculated self-consistently. This will allow us to perform more realistic calculations for peripheral reactions in the Boltzmann-Uehling-Uhlenbeck model.

The sensitivities to input parameters of the (p,${\ensuremath{\pi}}^{+}$) observables calculated using a relativistic one-nucleon distorted-wave Born approximation model are discussed. We investigate the effects of variations in bound state geometry and of ambiguities in the pion optical potential, as well as finite range effects in the production vertex.

A transformation is used to obtain sets of equivalent Lorentz scalar, Lorentz four-vector, and tensor optical potentials. These potentials are used in the Dirac equation for describing elastic scattering observables.

Elastic and inelastic $p+^{40}\mathrm{Ca}$ observables are calculated using a relativistic impulse approximation model for the diagonal optical potential and a simple collective ansatz for the transition potentials. The calculations were performed using Dirac coupled channel codes. Agreement with large angle elastic-scattering data is greatly improved by the inclusion of strongly coupled, lowlying collective states.

Although the cloudy bag model (CBM) can describe quite well p-wave \ensuremath{\pi}N scattering it has heretofore been unable to describe the energy dependence of the s-wave phase shifts. This problem is not unique to the CBM; it shows up dramatically in meson-exchange calculations. In this work it is shown that two higher-order graphs in the CBM, which cancel in the soft-pion limit, can cure this problem. One of the two graphs has properties similar to the exchange of a fictitious ``\ensuremath{\sigma}'' meson and provides long-range attraction. The other term, usually not included in meson-exchange potentials, provides short-range repulsion.

We present the first global relativistic optical-model treatment of proton-nucleus elastic scattering. Energy-dependent optical potential parameters for the Lorentz vector and scalar potentials of Dirac phenomenology are given. Several different assumptions regarding the optical-model energy dependence are considered. Constraints from relativistic mean-field theory are presented.

We show that the criticism of the work of Thies and of Cooper and Jennings is based on a misunderstanding of the relation between the relativistic and nonrelativistic models, as well as the relation between coordinate space and momentum space calculations. The presence of structure in the particle-only propagator is shown by direct calculation.

The Coulomb force as well as the diffusivity of the nuclear surface are expected to play an important role in peripheral heavy ion collisions at low and intermediate energies.1 Boltzmann-Uehling-Uhlenbeck (BUU) calculations should incorporate these effects. This has prompted us to consider static Vlasov solutions which have diffuse surfaces. Such solutions can be obtained by using a finite range force such as an Yukawa interaction2 or a gradient dependent interaction.3 Here we report a short summary of the properties of the static Vlasov solution with a diffuse surface through a Yukawa force. Details will be published elsewhere.4

There is increasing evidence that relativistic effects play an important role in the description of nuclear structure and reactions. The development of a relativistic impulse approximation (RIA) and its success at intermediate energies is a case in point. Although the RIA cannot be used to describe proton scattering at low energies it successfully describes recent p–12C data at 46.8 MeV. We discuss a phenomenological nuclear optical model approach based on the Dirac equation containing large cancelling Lorentz scalar and Lorentz vector potentials. The model is used to describe proton and neutron scattering at low energy (T