We have set limits on contributions of scalar interactions to nuclear betadecay. A magneto-optical trap (MOT) provides a localized source of atomssuspended in space, so the low-energy recoiling nuclei can freely escape and bedetected in coincidence with the beta. This allows reconstruction of theneutrino momentum, and the measurement of the beta-neutrino correlation, in amore direct fashion than previously possible. The beta-neutrino correlationparameter of the 0+ to 0+ pure Fermi decay of 38mK is$\tilde{a}$=0.9981+-0.0030+-0.0037, consistent with the standard modelprediction a=1.
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