This grant supports theoretical work in particle physics by Professor Matthew Reece of Harvard University. Dr. ReeceХs funded work will focus on better understanding the theoretical implications of the detection or nondetection of small asymmetries in the distribution of electrical charge in an electron. Distortions in the distribution of the electrical charge of an electron can be caused by the presence of fundamental particles, with the magnitude of the distortion inversely proportional to the mass of the intruding particle. The larger the particleХs mass, the smaller the distortion it causes. Theory tells us, however, that this only holds for particles that participate in so-called CP-violating interactions. Electron measurement experiments therefore do not put significant limits on these types of particles and it is important to understand which kinds of possible particles fall into this category, that is, to know which kinds of particles electron measurement experiments constrain. Professor ReeceХs research will categorize the types of particles and interactions that weakly violate CP-symmetry and therefore that could explain a tiny but nonzero distortion of an electronХs electrical charge. This will, in turn, provide help in interpreting the results of the experiments that aim to detect new particles through measuring the charge of electrons.К