G. C. Hillhouse

Pairing correlations and resonant states in the relativistic mean field theory

We present a simple scheme for taking into account the resonant continuum coupling in the relativistic mean field-BCS calculations. In this scheme, applied before in nonrelativistic calculations, the effect of the resonant continuum on pairing correlations is introduced through the scattering wave functions located in the region of the resonant states. These states are found by solving the relativistic mean field equations with scattering-type boundary conditions for the continuum spectrum. The calculations are done for the neutron-rich Zr isotopes. It is shown that the sudden increase of the neutron radii close to the neutron drip line, the so-called giant halo, is determined by a few resonant states close to the continuum threshold.

Analytic continuation of single-particle resonance energy and wave function in relativistic mean field theory

Single-particle resonant states in spherical nuclei are studied by an analytic continuation in the coupling constant (ACCC) method within the framework of the self-consistent relativistic mean field (RMF) theory. Taking the neutron resonant state nu1g(9/2) in Ca-60 as an example, we examine the analyticity of the eigenvalue and eigenfunction for the Dirac equation with respect to the coupling constant by means of a Pade approximant of the second kind. The RMF-ACCC approach is then applied to Zr-122 and, for the first time, this approach is employed to investigate both the energies, widths, and wave functions for lnot equal0 resonant states close to the continuum threshold. Predictions are also compared with corresponding results obtained from the scattering phase shift method.

Energy-dependent Lorentz covariant parameterization of the NN interaction between 50 and 200 MeV

For laboratory kinetic energies between 50 and 200 MeV, we focus on generating an energy-dependent Lorentz covariant parametrization of the on-shell nucleon-nucleon (NN) scattering amplitudes in terms of a number of Yukawa-type meson exchanges in first-order Born approximation. This parametrization provides a good description of NN scattering observables in the energy range of interest, and can also be successfully extrapolated to energies between 40 and 300 MeV.

Quasifree eta photoproduction from nuclei and medium modifications of resonances

This paper establishes the case that the process of quasifree

Validity of the relativistic impulse approximation for elastic proton-nucleus scattering at energies lower than 200 MeV

\ensuremath{\eta}

Analyzing power of the {sup 40}Ca(p-vector,p{alpha}) reaction at 100 MeV

photoproduction from nuclei is an important tool to study medium modifications and changes to the elementary process

Multistep direct mechanism in the (p-vector,{sup 3}He) inclusive reaction on {sup 59}Co and {sup 93}Nb at incident energies between 100 and 160 MeV

\ensuremath{\gamma}\stackrel{\ensuremath{\rightarrow}}{N}\ensuremath{\eta}N

RELATIVISTIC DESCRIPTION OF QUASIFREE ETA PHOTOPRODUCTION

in the nuclear medium. We investigate the sensitivity of the differential cross section, recoil nucleon polarization, and the photon asymmetry to changes in the elementary amplitude, medium modifications of the resonance

Relativistic calculations of quasielastic proton-nucleus spin observables using a complete Lorentz invariant description of the NN scattering matrix

{(S}_{11}{,D}_{13})

Relativistic plane wave model for complete sets of spin transfer observables for exclusive proton-induced knockout reactions

masses, as well as nuclear target effects. All calculations are performed within a relativistic plane-wave impulse approximation formalism resulting in analytical expressions for all observables. Our results indicate that polarization observables are largely insensitive to nuclear target effects. Depending on the type of coupling, the spin observables do display a sensitivity to the magnitude of the