Applications of Partially Quenched Chiral Perturbation Theory
  Partially quenched theories are theories in which the valence- and sea-quark masses are different. Here, we will discuss the nonanalytic one-loop corrections to some physical quantities, using partially quenched chiral perturbation theory. In particular, we will focus on the results for Goldstone boson masses to illustrate the general features of our calculation. 
Maarten Golterman and Ka Chun Leung