Superallowed beta decay of nuclei with a >or= 62: the limiting effect of weak Gamow-Teller branches. Academic Article uri icon


  • The most precise value of V(ud), which is obtained from superallowed nuclear beta decay, leads to a violation of Cabibbo-Kobayashi-Maskawa unitarity by 2.2sigma. Experiments are underway on two continents to test and improve this result through decay studies of odd-odd N = Z nuclei with A>or=62. We show, in a series of illustrative shell-model calculations, that numerous weak Gamow-Teller branches are expected to compete with the superallowed branch in each of these nuclei. Though the total Gamow-Teller strength is significant, many of the individual branches will be unobservably weak. Thus, new techniques must be developed if reliable ft values are to be obtained with 0.1% precision for the superallowed branches.

published proceedings

  • Phys Rev Lett

author list (cited authors)

  • Hardy, J. C., & Towner, I. S.

citation count

  • 51

complete list of authors

  • Hardy, JC||Towner, IS

publication date

  • June 2002