Photoproduction of Pseudoscalar Mesons from Nuclei
msra(2000)
摘要
The subject of this doctoral study is the pseudoscalar meson photoproduction
from nuclei. Two types of processes are investigated in this regard: coherent
and quasifree processes. In the case of the coherent process, we study it for
the photoproduction of pion and eta mesons. We place special emphasis on the
various sources that put into question earlier
nonrelativistic-impulse-approximation calculations. These include: final-state
interactions, relativistic effects, off-shell ambiguities, and violations to
the impulse approximation. By far the largest uncertainty emerges from the
ambiguity in extending the many on-shell-equivalent representations of the
elementary amplitude off the mass shell. In the case of the quasifree process,
we study it for the photoproduction of the kaon meson. We compute the recoil
polarization of the lambda-hyperon and the photon asymmetry as well as the
differential cross section. By introducing the notion of a ``bound-nucleon
propagator'' we exploit Feynman's trace techniques to develop closed-form,
analytic expressions for all photoproduction observables. Our results indicate
that polarization observables are sensitive only to the fundamental physics,
making them ideal tools for the study of modifications to the elementary
process in the nuclear medium.
更多查看译文
关键词
relativistic effects,cross section
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要