Parity-Violating Electron Scattering at Jefferson Laboratary with 11 GeV
MOLLER (Measurement of Lepton-Lepton Electroweak Reaction)
A new Department of Energy (DOE) Major Item of Equipment (MIE project) is under construction to measure the parity-violating asymmetry in the scattering of longitudinally polarized 11 GeV electrons from the atomic electrons in a liquid hydrogen target. Our goal is to measure the tiny asymmetry of about 35 parts per billion to 2.4% of itself. This would measure the weak mixing angle, a fundamental parameter of the electroweak theory, to an accuracy close to 0.1%, approaching the accuracy of the two best measurements at high energy colliders. This provides indirect access ot new dynamics at multi-TeV scales, in a manner complementary to direct searches at the Large Hadron Collider.
The MOLLER MIE Project received CD-0 approval in December 2016 and CD-1 Approval in December 2020.
We are currently in the engineering design phase and anticipate getting CD-2 approval in early 2023, with construction following soon after. We plan to complete installation of the apparatus and begin commissioning the experiment in late 2025.
Parity-Violating Deep Inelastic Scattering: SoLID (Solenoidal Large Intensity Device)
A new proposal has been developed to measure the parity-violating asymmetry in the deep inelastic scattering of polarized electrons off a liquid deuterium target. The goal is to improve our knowledge of lepton-quark weak neutral current coupling constants; one particular linear combination of these constants would improve by more than a factor of 30. Such a measurement would provide unique information on possible new dynamics at the TeV scale in a manner complementary to direct searches at the Large Hadron Collider.
The centerpiece of the proposal is a new spectrometer, called SoLID, which is based on a large solenoidal manget.