The Nucleon in a Strange Light
21 September 2016
NSCL Lecture Hall
University of Illinois at Urbana-Champaign
Parity-violating electron scattering allows us to measure the weak interaction analog of the ordinary electromagnetic scattering. Because the weak and electromagnetic charges of quarks differ, it is possible to extract from such measurements individual flavor contributions to, for example, the proton charge distribution and its magnetic moment. The weak interaction also involves a coupling to an axial current; I will discuss measurement of the nucleon anapole moment and some limitations in its interpretation. The set of these measurements, when combined with results of shorter distance scale experiments, suggests a picture of the nucleon in which light quark pairs âliveâ for a relatively long time; strange quark pairs, by contrast, appear to be relatively short-lived.