2023 115 P

Dilaton Chiral Perturbation Theory at Next-to-Leading Order

By: Andrew Freeman

Department: Physics & Astronomy

Faculty Advisor: Dr. Maarten Golterman

It has been observed that a flavor-singlet scalar meson that is approximately as light as the pion exists in numerical simulations of the SU(3) gauge theory with 8 fermions in the fundamental representation. Confinement and chiral symmetry breaking still take place in this theory, but the beta function is small enough to where this light scalar could be the Nambu-Goldstone boson associated with the breaking of dilatation symmetry. In order to account for the presence of this light scalar meson, a low-energy effective action that includes pions and this "dilatonic" meson was developed. This effective theory has been given the name dilaton chiral perturbation theory (dChPT). We further explore the predictive power of dChPT by calculating the next-to-leading order contributions for the pion decay constant and the pion mass squared.