Physics – Nuclear Physics – Nuclear Experiment
Scientific paper
2008-02-05
Physics
Nuclear Physics
Nuclear Experiment
12 pages, 8 figures, LaTeX. Invited talk at the International Symposium on Cosmology and Particle Astrophysics (CosPA07), Taip
Scientific paper
10.1142/S0217732308027643
After almost five decades of study of parity violation in hadronic systems, the determination of the seven weak meson-nucleon couplings is still incomplete. Whereas parity violation in nuclear systems is complicated by the intricacies of QCD, measurements of parity violation in the much simpler proton-proton system are more straightforward to interpret. We now have three such precision pp experiments at 13.6, at 45, and 221 MeV. Today there are also better possibilities for theoretical interpretation using effective field theory. In electron-proton scattering, parity violating ep experiments such as SAMPLE, G0, HAPPEX, and PVA4 have already shown that the strange quark contributions to the charge and magnetization distributions of the nucleon are tiny. When analyzed together, the results have also greatly improved knowledge of the proton's "weak charge" (Q^p_weak = 1-4sin^2\theta_W at tree level). The Q^p_weak experiment at JLab will further improve this, determining the proton's weak charge to a precision of about 4%. Such a precision will either establish conformity with the Standard Model of quarks and leptons or point to New Physics. Following the upgrade of CEBAF at JLab to 12 GeV, a parity violating electron-electron (Moller) scattering experiment similar to SLAC E158, will measure the weak charge of the electron and hence sin^2\theta_W at low energy with a precision comparable to the most precise individual measurements at the Z0 pole (to about +/- 0.00025). This experiment will be complementary to Q^p_weak in terms of sensitivity to New Physics.
No associations
LandOfFree
From Hadronic Parity Violation to Parity-Violating Electron Scattering and Tests of the Standard Model does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with From Hadronic Parity Violation to Parity-Violating Electron Scattering and Tests of the Standard Model, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and From Hadronic Parity Violation to Parity-Violating Electron Scattering and Tests of the Standard Model will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-46154