European Physical Journal A, Hadrons and Nuclei vol:42 issue:3 pages:327-331
Precision correlation measurements in nuclear beta decay using atom and ion traps have made
significant progress since the last ENAM2004 Conference. We review here the achievements and plans of
different projects and discuss for each of them their potential to contribute to the determination of the Vud
element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix. This matrix element has traditionally
been determined from the analysis of data in nuclear superallowed 0+ → 0+ transitions, neutron decay
and pion beta decay but can also independently be determined from data in nuclear mirror transitions.
This requires the measurement of correlation parameters in such decays to determine the Gamow-Teller
to Fermi mixing ratio which, in most cases, dominates the error on the extracted value of |Vud|.