Conveners
Electroweak Probes: Electroweak Probes
- Franziska Hagelstein (AEC, University of Bern)
We study the quark and anti-quark Wigner distributions of kaon in light-cone quark model. Wigner distributions are evaluated by using overlap representation of light-cone wavefunctions. Specifically, we investigate the Wigner distributions of unpolarized and longitudinally-polarized quark and anti-quark in unpolarized kaon in impact-parameter space and momentum space.
The nucleon axial charge $g_A$, measures the strength of the coupling of the axial current of the standard model to the nucleon, controlling the rate of beta decay, for example. A determination of $g_A$ directly from QCD is complicated by the non-perturbative nature of QCD, but is important for benchmarking the application of lattice QCD to problems in nuclear physics, and for aiding in...
Following on our recent per-cent-level determination of $g_A$, I will describe our efforts to reduce the theoretical uncertainty from 1% to 0.2%, a level at which we will have a 4-sigma discriminating prediction of the neutron lifetime, to match the level of precision of the current experimental discrepancy. I will describe the challenges that must be overcome and our progress to doing so...
