Proton weak charge determined for first time
NEWPORT NEWS, VA, Sept. 17, 2013 – Researchers have made the first experimental determination of the weak charge of the proton in research carried out at the Department of Energy's Thomas Jefferson National Accelerator Facility (Jefferson Lab).
The results, accepted for publication in Physical Review Letters, also include the determinations of the weak charge of the neutron, and of the up quark and down quark. These determinations were made by combining the new data with published data from other experiments. Although these preliminary figures are the most precise determinations ...