Speaker
Roger Carlini
(J)
Description
The QWeak collaboration has un-blinded its final result from data taken at Jefferson Laboratory.
We describe the longitudinally polarized electron-proton elastic scattering technique employed to
isolate and extract the scattering asymmetry, which constituted our observable. The precision
obtained from our combined two run periods was ±9 ppb. The results from these run periods
were in excellent agreement. Some of the backgrounds and corrections applied in the
measurement will be discussed. We provide the results from several methods used to extract
consistent values of the proton's weak charge Qp
W from our measurement. From the proton's
weak charge is obtained a result for sin2qW at the low Q2 scale of the measurement, which is a
sensitive Standard Model test of the running of sin2qW. This defines a mass reach for any parity
violating semi-leptonic physics beyond the Standard Model. Implications for specific physics
models will be discussed. We also present results for the strange and axial form factors obtained
from a fit which included additional existing parity-violating electron scattering data. 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 neutron's weak charge.
.......
This work was supported by DOE Contract No. DEAC05-06OR23177, under which Jefferson
Science Associates, LLC operates Thomas Jefferson National Accelerator Facility. Construction
and operating funding for the experiment was provided through the U.S. Department of Energy
(DOE), the Natural Sciences and Engineering Research Council of Canada (NSERC), and the
National Science Foundation (NSF) with university contributions from the College of Willi
