Jun 2 – 7, 2019
Carnegie Mellon University
America/New_York timezone

Results from the Qweak Parity Violation Experiment at Jefferson Laboratory and Implications for Future Measurements

Jun 4, 2019, 11:15 AM
McConoomy Auditorium (CMU Cohon University Center)

McConoomy Auditorium

CMU Cohon University Center

Invited Fundamental Symmetries Menu-2019 Plenary


Dr Roger Carlini (Jefferson Laboratory)


Experimental programs in the fields of nuclear and particle physics are searching for evidence of physics beyond that explained by current theories. Indirect searches using precise measurements of well predicted Standard Model observables allow highly targeted tests that can reach mass and energy scales beyond those directly accessible by today’s high energy accelerators. From our precise measurement (-226 ±9 ppb) of the parity-violating (PV) asymmetry in the scattering of longitudinally polarized electrons on protons, we extract the proton's weak charge and the weak mixing angle sin^2(Theta_W) at low Q^2. Several consistent methods used to extract the proton’s weak charge from the data will be discussed. This allows a mass reach for any parity violating semi-leptonic physics beyond the Standard Model at the multi-TeV scale. Implications for several specific models will be presented. The results for the strange and axial form factors obtained from a fit which included additional existing PV electron scattering data will also be presented. In conjunction with existing atomic parity violation results on 133Cs we also extract the vector weak quark couplings C1u and C1d. The latter are combined to obtain the weak charge of the neutron. This talk will also briefly discuss the discover space available to future PV measurements in the context of the combine constraints from existing high precision measurements.

Graduate Student No
Early Consideration No

Primary author

Dr Roger Carlini (Jefferson Laboratory)

Presentation materials