Heavy Meson And Meson Lagrangian Lightweight Interactions

Interaction between hadrons is a fundamental topic in Quantum Chromodynamics.Because of its confinement nature, it is difficult to deal with this topic. One way out of thisdifficulty is using effective field methods which share the same symmetry as QuantumChromodynamics. In low energy region, light quarks adhere to approximate chiral symmetry,given this symmetry, effective theories such as chiral perturbative theory and linear sigmamodels have been developed. In order to investigate conveniently interaction between heavymesons and light mesons, one has developed heavy meson effective theory and has done aseries of studies.At present, the heavy meson effective theory one often uses incorporates the nonlinearchiral theory and the heavy quark effective theory. Since the nonlinear chiral theory containsonly light pseudoscalars as its basic degrees of freedom, this theory can be used to deal withinteraction between heavy mesons and light pseudoscalars, but can not be used to deal withinteraction between heavy mesons and light scalars. Nowadays the structure of light scalarsbelow1GeV is not clear yet, so it will be helpful to explore interaction between light scalarsand heavy mesons. The linear realization of chiral theory can be a cornerstone for dealingwith this topic. The typical linear realization of chiral theory is linear sigma models. Itsexperimental base is the existence of sigma meson which was confirmed recently, although itsstructure is still an open question.In this thesis first we introduce the heavy meson chiral theory systematically. Here wetake the popular nonlinear realization scheme as an example, we also introduce the method tointroduce light vectors by the hidden local gauge theory.Then we investigate the heavy meson chiral theory with light scalars. We deduce thelowest order interaction lagrangian in detail and give an explicit form, it is convenient for oneto study decay and scattering between heavy and light mesons by using our results.Moreover, we add symmetry broken terms arising from the difference of light quarks, since itseffect can not be neglected, it is necessary to take it into account.