| In this thesis we investigate Heavy Baryon Chiral Perturbation Theory (HBchiPT), an important method for describing baryon interactions at low momentum. However, some treatments to date have disagreed with experimental data. We postulate that the problem may lie with the treatment of hadron masses in the theory, and consider multiple possible solutions.;In some previous approximations of HBchiPT, the physical mass of the kaon is used, while the mass of the pion is set to zero. Further, the mass splitting between the decuplet and octet baryons (Deltam) is set to zero. In this limit, since the octet baryon mass is "rotated away," the only hadronic mass scale in the theory is the mass of the kaon. This simplifies the calculation, and has been effective when applied to some low-energy baryon processes. Here, we add more mass scales to the theory and investigate the modified predictions that result.;Our goal is to better determine the low energy constants (LECs) that appear in the effective theory. These LECs are not known only because it is not possible to solve Quantum Chromodynamics (QCD) and match the results to HBchiPT. We do a best fit analysis on results of our calculations in comparison with experiment. We employ four calculations: axial currents, strong decuplet baryon decay, O-- decay, and s-wave nonleptonic hyperon decays. We investigate several mass schemes and their subsequent results, including mpi = 0 and Delta m = 0. Then we consider finite values of m pi and Deltam. Finally, we use isospin conserving physical baryon mass values.;We find that including Deltam in the calculations and considering only nonanalytic terms is a reasonable strategy and that our results should be useful to investigate open problems. We comment on the inclusion of Deltam and its consistency in power counting with the strange quark mass ms as opposed to m1/2s , as has been suggested. |
