Muonium formation in nonpolar liquids

Despite the very wide acceptance of the spur model of positronium formation there has been continuing criticism of the analogous model for muonium formation. After critical comparison of the muonium and positronium formation processes it is shown how differences in muonium and positronium behaviour can be explained by differences in their properties and the way in which measurements are made. It is concluded that the sparse data presently available for muonium are consistent with a spur formation process. (author)