Study of the pion-nucleus optical potential

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1981

OSTI ID:6082710

Stricker, K S

The optical potential model is a convenient means of characterizing the interaction of the pion with the nucleus. Its simplicity makes it practical for the calculation of elastic scattering and pion distorted waves for more complicated processes. Its success in reproducing the early pion data and the existence of new, higher quality data motivate the present investigation. An optical potential for pion-nucleus interactions in the energy range 0 to 250 MeV pion kinetic energies is constructed with the Watson multiple scattering series and the ..pi..N transition amplitude as starting point. The pion-nucleon to pion-nucleus center of mass transformation is calculated to first order in the ratio of total pion energy to nucleon mass. Multiple scatttering corrections in low energy approximation are included to second order in the s-wave and to all orders in the p-wave (the Lorentz-Lorenz or Ericson-Ericson effect). True pion absorption terms, proportional to the square of the nuclear density, are included in both s and p-wave parts of the potential. Pauli blocking is approximated, and an energy shift due to the Coulomb interaction is incorporated. The potential parameters are taken from the experimental ..pi..N phase shifts and theoretical calculations. The potential, of Kisslinger type, is incorporated in coordinate space computer codes which calculate pionic atom level shifts and widths, elastic scattering differential cross sections, and total and partial cross sections. These calculations are compared to the current experimental data. It is found that at low energies (0 to 50 MeV) the potential produces elastic cross sections which fit the data provided the s-wave repulsion is increased. The pionic atom level data require more absorptive strength than that given by current calculations, as well as increased repulsion consistent with the scattering results. The general features of the resonance region elastic scattering and total cross sections are well reproduced.

• Research Organization: Michigan State Univ., East Lansing (USA)
• OSTI ID: 6082710
• Country of Publication: United States
• Language: English

Related Subjects

645206* -- High Energy Physics-- Particle Interactions & Properties-Theoretical-- Strong Interactions
Baryon No. = 1-- (-1987)
653003 -- Nuclear Theory-- Nuclear Reactions & Scattering
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
CHARGED-PARTICLE REACTIONS
ELASTIC SCATTERING
ENERGY RANGE
HADRON REACTIONS
HADRON-HADRON INTERACTIONS
INTERACTIONS
MESON REACTIONS
MESON-BARYON INTERACTIONS
MESON-NUCLEON INTERACTIONS
MEV RANGE
MEV RANGE 01-10
MEV RANGE 10-100
NUCLEAR POTENTIAL
NUCLEAR REACTIONS
OPTICAL MODELS
PARTIAL WAVES
PARTICLE INTERACTIONS
PION REACTIONS
PION-NUCLEON INTERACTIONS
POTENTIALS
SCATTERING