[PAST EVENT] Ekaterina V. Mastropas: Physics Dissertation Defense

November 20, 2014
Small Hall, Room 122
300 Ukrop Way
Williamsburg, VA 23185Map this location
The work presented here is devoted to the calculations of the decay constants of the pion and its excited states. All calculations were carried out in the framework of lattice quantum chromodynamics, a well-established formalism of strong interactions enabling the ab initio solution of the theory. After a short introduction and review of the fundamental approaches and methods commonly used in lattice QCD, I provide a detail description of the numerical simulations which were performed at three values of the pion mass between 400 and 700 MeV, using an anisotropic clover fermion action with three flavors of quarks. The results obtained indicate that the decay constant of the first excitation, and more notably of the second, is suppressed with respect to that of the ground-state pion, but that the suppression shows little dependence on the quark mass. The second part of this thesis is focused on applications of the methods of perturbation theory to lattice QCD. Here, I give some motivation, and describe the main techniques of perturbative calculations of the lattice, emphasizing its distinctions from the continuum counterpart. I then employ the same anisotropic clover action, that was used in numerical study, for derivation of lattice Feynman rules which might be used for the calculations of the renormalization parameters helping to connect bare lattice results with real physics.

Ekaterina Valentinovna Mastropas was born in Rostov-on-Don, Russia, in 1981. She grew up and attended the public schools in the same city, and after graduation from high school she began undergraduate studies at the Physics Department of Rostov State University (RSU). She remained at RSU from 1997 to 2003, acquiring Bachelor of Science (B.S.) and Master of Science (M.S.) degrees in theoretical and computational physics. During the next five years, she worked in various private companies while teaching part-time undergraduate courses at Rostov State Pedagogical University.

In August 2008, Ekaterina moved to Williamsburg, VA, to begin her graduate study at the College of William and Mary. She received her M.S. degree in physics in January of 2010, and soon after that she started working under the advisory of Prof. David Richards within Nuclear and Hadronic Theory group at W&M and Lattice QCD group at Jefferson Lab. Her Ph.D. thesis is devoted to the exploration of the decay constant of the pion and its excitations using methods of lattice quantum chromodynamics.