A recent corrective paper by particle theorists Masashi Hayakawa (KEK, Tsukuba, Japan) and Toichiro Kinoshita (Cornell University) is something of a cautionary tale. 1 Since the mid-1980s, Kinoshita and various colleagues have been laboring to calculate the anomalous magnetic moment of the muon (α µ ) from the standard model of particle theory with ever greater precision. The task has taken on particular urgency in the past year, as the pioneering Brookhaven experiment led by Vernon Hughes and Lee Roberts began to improve on earlier measurements of α µ by more than an order of magnitude.
Hughes and company attracted considerable attention last year by reporting a 2.6-standard-deviation (σ) discrepancy between their first results and the standard-model prediction. 2 (See Physics Today, Physics Today 0031-9228 54 4 2001 18 https://doi.org/10.1063/1.1372101 April 2001, page 18 .) The discrepancy was particularly tantalizing because its magnitude and sign hinted at the...
