Low energy searches for Physics Beyond the Standard Model

The Standard Model has been an extremely successful theory, with the most recent triumph being the discovery of the Higg's boson at CERN. However, it remains incomplete - it doesn't yet explain dark matter or dark energy (which make up 97% of the energy in the universe) nor does it incorporate a theory of quantum gravity. In addition, although the description of electromagnetism and the weak force have been unified into a quantum electroweak theory, they have not been unified with the theory of the strong force - quantum chromodynamics. These questions, among others, have motivated many searches for Physics Beyond the Standard Model. Among them are low-energy, parity-violating electron scattering experiments such as Qweak and MOLLER, which measure the weak mixing angle sin2θW with such precision that deviations from the Standard Model prediction tell us about the masses and couplings of new exchange particles. MOLLER will improve on the SLAC E158 measurement of the parity-violating asymmetry by more than a factor of five, yielding the most precise measurement of the weak mixing angle to date. The resulting discovery reach is unmatched by any proposed experiment measuring a flavor- and CP-conserving process over the next decade, and yields a unique window to new physics at MeV and multi-TeV scales, complementary to direct searches at high energy colliders such as the Large Hadron Collider (LHC) at CERN. The experiment takes advantage of the unique opportunity provided by the upgraded electron beam energy, luminosity, and stability at Jefferson Laboratory and the extensive experience accumulated in the community after a round of recent successfully completed parity-violating electron scattering experiments.

Dr. Mammei has been an assistant professor in the Physics and Astronomy Department at the University of Manitoba for four years. She did her postdoctoral research at Jefferson Lab, in Newport News, Va under the supervision of Dr. Krishna Kumar. She graduated from Virginia Tech with a PhD in Nuclear Physics in 2010. Her most recent work is primarily the use of polarized electrons to study nuclear and nucleon structure by exploiting parity violation in the weak interaction. She has worked on experiments such as G0, which measured the strange quark content of the nucleon, Qweak, which has made the first measurement of the weak charge of the proton, and PREX, which confirmed that there is a neutron skin in lead. She is currently working on PREX II and CREX, which will measure the neutron skin thickness in heavy nuclei with enough precision to impact our understanding of 3 nucleon forces and neutron star structure. She is also the Canadian PI on the MOLLER experiment executive board, as well as being the Spectrometer Working Group leader. MOLLER will be an ultra-precise measurement of the weak charge of the electron.