Precise half-life measurement of the superallowed β+ emitter 38Km

The half-life of K-38(m) has been measured to be 924.46(14) ms, a result that is a factor of two more precise than any of the five previous measurements of this quantity. The previous results are not consistent with one another, but our result agrees well with the two most recent ones. The derived f t value for K-38(m) is now one of the three most precisely known superallowed f t values.