A relativistic microscopic approach and a semi-classical approach to high-energy meson-nucleus interactions

Thesis/Dissertation · Thu Dec 31 23:00:00 EST 1992

OSTI ID:7233151

Chen, C M.J.

An optical-potential model originally developed for low-energy (T[sub [pi]] [le] 300 MeV) pion-nucleus scattering in momentum space was extended to treat both kaon-nucleus and high-energy pion-nucleus elastic scattering (300 MeV [le] T[sub [pi]] [le] 1 GeV). The optical model utilizes Lorentz covariantly normalized wave functions, full relativistic kinematics and a Klein-Gordon propagator in the Lippmann-Schwinger equation, finite range nucleon form factors plus various nuclear medium corrections. The fermi-averaging integration can be performed exactly. This work on the K[sup +]-[sup 12]C and K[sup +]-[sup 40]Ca elastic differential cross section at a kaon lab momentum of 800 MeV/c confirms a nucleon swelling effect. An enhancement in the two-body amplitude is needed to eliminate the discrepancy between the data and theory. For the high-energy pion-nucleus scattering problem, the optical model approach has been limited to light nuclei (A [le] 90) and/or at low energy (T[sub [pi]] [le] 500 MeV). A simple but effective eikonal approximation for high-energy pion scattering was developed. Both the Coulomb interaction and the semi-classical Wallace corrections are included in the eikonal approximation. The same target wave functions and two-body amplitude are used in both the optical model and the eikonal calculation. Comparison of the results from both calculations shows that the fermi-averaging integration and various sources of non-locality are not important at high energies. The eikonal approximation gives very reliable results, especially for heavy nuclei (A [ge] 28). Predictions utilizing the eikonal approximation are made for elastic differential cross sections of [pi][sup [+-]] on various target nuclei. Contributions from the Coulomb interaction and the Wallace corrections in this energy region are found to be important. Future prospects of studying high-energy pion scattering utilizing the eikonal approximation are discussed.

• Research Organization: Texas A and M Univ., College Station, TX (United States)
• OSTI ID: 7233151
• Country of Publication: United States
• Language: English

Related Subjects

663460* -- Meson- & Hyperon-induced Reactions & Scattering-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
CALCIUM 40 TARGET
CARBON 12 TARGET
CHARGED-PARTICLE REACTIONS
EIKONAL APPROXIMATION
ENERGY RANGE
EQUATIONS
FIELD EQUATIONS
FORM FACTORS
HADRON REACTIONS
HADRON-HADRON INTERACTIONS
INTEGRAL EQUATIONS
INTERACTIONS
KAON PLUS REACTIONS
KAON REACTIONS
KAON-NUCLEON INTERACTIONS
LIPPMANN-SCHWINGER EQUATION
MESON REACTIONS
MESON-BARYON INTERACTIONS
MESON-NUCLEON INTERACTIONS
NUCLEAR REACTIONS
PARTICLE INTERACTIONS
PARTICLE KINEMATICS
PARTICLE PROPERTIES
PION-NUCLEON INTERACTIONS
RELATIVISTIC RANGE
SEMICLASSICAL APPROXIMATION
SINE-GORDON EQUATION
TARGETS