First measurement of proton’s weak charge provides no surprises
http://www.gizmag.com/first-measurement-proton-weak-interaction-charge/29169/
An international team of researchers at the US Department of Energy’s Jefferson Accelerator Laboratory in Virginia has measured the weak charge of the proton for the first time. Although first measurements of fundamental quantities always raise the hope of observing new physics, early results from the Q-Weak experiment find the weak charge of the proton and the neutron to be consistent with predictions of the Standard Model. Analysis of additional data will help pin down this result.
The well-named weak interaction between particles is so weak that neutrinos (particles that interact only through the weak interaction and gravity) pass easily through a light-year of lead without interacting with any of the lead nuclei.
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