decay of (38)Ca: sensitive test of isospin symmetry-breaking corrections from mirror superallowed 0+ 0+ transitions. Academic Article uri icon


  • We report the first branching-ratio measurement of the superallowed 0+0+ transition from Ca38. The result, 0.7728(16), leads to an ft value of 3062.3(68)s with a relative precision of 0.2%. This makes possible a high-precision comparison of the ft values for the mirror superallowed transitions, Ca3838mK and K38mAr38, which sensitively tests the isospin symmetry-breaking corrections required to extract Vud, the up-down quark-mixing element of the Cabibbo-Kobayashi-Maskawa (CKM) matrix, from superallowed decay. The result supports the corrections currently used and points the way to even tighter constraints on CKM unitarity.

published proceedings

  • Phys Rev Lett

altmetric score

  • 1.25

author list (cited authors)

  • Park, H. I., Hardy, J. C., Iacob, V. E., Bencomo, M., Chen, L., Horvat, V., ... Towner, I. S.

citation count

  • 24

complete list of authors

  • Park, HI||Hardy, JC||Iacob, VE||Bencomo, M||Chen, L||Horvat, V||Nica, N||Roeder, BT||Simmons, E||Tribble, RE||Towner, IS

publication date

  • March 2014