Branching ratios for the beta decay of 21Na
  We have measured the beta-decay branching ratio for the transition from 21Na to the first excited state of 21Ne. A recently published test of the standard model, which was based on a measurement of the beta-nu correlation in the decay of 21Na, depended on this branching ratio. However, until now only relatively imprecise (and, in some cases, contradictory) values existed for it. Our new result, 4.74(4)%, reduces but does not remove the reported discrepancy with the standard model. 
V.E. Iacob, J.C. Hardy, C.A. Gagliardi, J. Goodwin, N. Nica, H.I.   Park, G. Tabacaru, L. Trache, R. Tribble, Y. Zhai and I....