6 research outputs found
Low-energy p-d Scattering: High Precision Data, Comparisons with Theory, and Phase-Shift Analyses
Angular distributions of sigma(theta), A_y, iT_11, T_20, T_21, and T_22 have
been measured for d-p scattering at E_c.m.=667 keV. This set of high-precision
data is compared to variational calculations with the nucleon-nucleon potential
alone and also to calculations including a three-nucleon (3N) potential.
Agreement with cross-section and tensor analyzing power data is excellent when
a 3N potential is used. However, a comparison between the vector analyzing
powers reveals differences of approximately 40% in the maxima of the angular
distributions which is larger than reported at higher energies for both p-d and
n-d scattering. Single-energy phase-shift analyses were performed on this data
set and a similar data set at E_c.m.=431.3 keV. The role of the different
phase-shift parameters in fitting these data is discussed.Comment: 18 pages, 6 figure
Four-nucleon scattering with a correlated Gaussian basis method
Elastic-scattering phase shifts for four-nucleon systems are studied in an
- type cluster model in order to clarify the role of the tensor
force and to investigate cluster distortions in low energy and
scattering. In the present method, the description of the cluster wave function
is extended from a simple (0) harmonic-oscillator shell model to a few-body
model with a realistic interaction, in which the wave function of the
subsystems are determined with the Stochastic Variational Method. In order to
calculate the matrix elements of the four-body system, we have developed a
Triple Global Vector Representation method for the correlated Gaussian basis
functions. To compare effects of the cluster distortion with realistic and
effective interactions, we employ the AV8 potential as a realistic
interaction and the Minnesota potential as an effective interaction. Especially
for , the calculated phase shifts show that the and channels
are strongly coupled to the channel for the case of the realistic
interaction. On the contrary, the coupling of these channels plays a relatively
minor role for the case of the effective interaction. This difference between
both potentials originates from the tensor term in the realistic interaction.
Furthermore, the tensor interaction makes the energy splitting of the negative
parity states of He consistent with experiments. No such splitting is
however reproduced with the effective interaction