Applications of Chiral Perturbation Theory in Reactions with Heavy Particles

• Main Author: Stewart, Iain W.
• Format: Others
• Language: en
• Published: 1999
• Online Access: https://thesis.library.caltech.edu/10373/2/Stewart%20_iw_1999.pdf; Stewart, Iain W. (1999) Applications of Chiral Perturbation Theory in Reactions with Heavy Particles. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/w8fe-ww63. https://resolver.caltech.edu/CaltechTHESIS:08082017-105330690 <https://resolver.caltech.edu/CaltechTHESIS:08082017-105330690>

Effective field theory techniques are used to describe the interaction of heavy hadrons in a model independent way. Predictability is obtained by exploiting the symmetries of QCD. Heavy hadron chiral perturbation theory is reviewed and used to describe D* decays. The phenomenologically important D*Dπ coupling is extracted from data working to first order in the chiral and heavy quark symmetry breaking parameters. A method is described for determining |V_ub| from exclusive semileptonic B and D decays with 10% uncertainty. An effective field theory for two-nucleon systems is then discussed. The large S-wave scattering lengths necessitate expanding around a non-trivial fixed point. A detailed discussion of the interplay between renormalization and the power of counting is given. In power counting pion interactions with nucleons it is useful to consider three classes of pion: potential, radiation, and soft. A power counting for massive radiation is developed. Finally, it is shown that the leading terms in the effective theory for nucleon-nucleon interactions are invariant under Wigner's SU(4) spin-isospin symmetry in the infinite scattering length limit.