# Joseph M. Karpie

## Research Interest

I obtained a Bachelor's degree from RPI and a Master's and Ph.D. from William and Mary under Kostas Orginos. During my Ph.D., I worked closely with the Theory Group Jefferson Lab. I am now a postdoc working with Norman Christ and Bob Mawhinney as part of the RBC/UKQCD collaboration. I use numerical techniques to study the strong interaction and the properties of hadrons.

I study the impact of QCD on the CP violation in Weak decays. Specifically, the rates at which neutral kaons decay to 2 or 3 pions can be used to determine how much CP symmetry is violated by the Weak interaction. Precision calculations with numerical lattice QCD are necessary to determine the Standard Model prediction of such violation for comparison with the experiment. I work on various aspects of the lattice implementation of calculation epsilon and epsilon'. Previously I have studied the parton distributions within the nucleon and pion. The ways in which quarks and gluons are distributed within a hadron explain the decomposition of mass and spin of the hadron as well as properties such as form factors. Calculations of "pseudo-distributions" can be used to determine the parton distributions from lattice QCD.