Experimental Validation of the Largest Calculated   Isospin-Symmetry-Breaking Effect in a Superallowed Fermi Decay
  A precision measurement of the gamma yields following the beta decay of 32Cl has determined its isobaric analogue branch to be (22.47^{+0.21}_{-0.19})%. Since it is an almost pure Fermi decay, we can also determine the amount of isospin-symmetry breaking in this superallowed transition. We find a very large value, delta_C=5.3(9)%, in agreement with a shell-model calculation. This result sets a benchmark for isospin-symmetry-breaking calculations and lends support for similarly-calculated, yet smaller, corrections that are currently applied to 0+ -> 0+ transitions for tests of the Standard Model. 
D. Melconian, S. Triambak, C. Bordeanu, A. Garc\'ia, J. C. Hardy, V.   E. Iacob, N. Nica, H. I. Park, G. Tabacaru, L. Trache...
nucl-ex nucl-th