Test of the Conserved Vector Current Hypothesis in T=1/2 Mirror Transitions and New Determination of |Vud|

The Vud element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix has traditionally been determined from the analysis of data in nuclear superallowed 0+→0+ transitions, neutron decay, and pion beta decay. After providing a new test of the conserved vector current hypothesis, we present here a new independent determination of |Vud| from a set of five T=1/2 nuclear mirror transitions. The extracted value, |Vud|=0.9719±0.0017, is at 1.2 combined standard deviations from the value obtained from superallowed 0+→0+ transitions and has a precision comparable to the value obtained from neutron decay experiments