June 20 h. 15.00
Fisica del Nucleo
Krishna Kumar , Massachusettes U. - USA
Parity-Violating Electron Scattering: Past, Present and Future
The study of the weak neutral current (WNC), mediated by the Z boson, plays a central role in tests of strong and electroweak interactions.
In fixed target electron scattering, the WNC amplitude can be isolated by measuring the fractional difference in the scattering of right- and left-handed longitudinally polarized electrons on unpolarized nuclear targets. Such asymmetries are a signature of parity-violation and range from 100 parts per million (ppm) in deep inelastic scattering to as small as 0.1 ppm in electron-electron scattering. After a brief historical overview, new results from the E158 experiment at SLAC and the HAPPEX program at Jefferson Lab will be presented. New ideas on parity-violating electron scattering for future accelerator facilities will be discussed.