Study of D sub s sup + r arrow. phi. e sup +. nu. sub e and the absolute D sub s sup + r arrow. phi. pi. sup + branching fraction

We have searched for the decay {ital D}{sub {ital s}}{sup +}{r arrow}{phi}{ital e}{sup +}{nu}{sub {ital e}} in data from the Fermilab charm photoproduction experiment E691. The resulting upper limit is {ital B}({ital D}{sub {ital s}}{sup +}{r arrow}{phi}{ital e}{sup +}{nu}{sub {ital e}}){lt}0.45{ital B}({ital D}{sub {ital s}}{sup +}{r arrow}{phi}{pi}{sup +}). Since the branching fraction for {ital D}{sub {ital s}}{sup +}{r arrow}{phi}{ital e}{sup +}{nu}{sub {ital e}} can be calculated from the measured branching fraction {ital B}({ital D}{sup +}{r arrow}{ital {bar K}} {sup *0}{ital e}{sup +}{nu}{sub {ital e}}) to be (1.7{plus minus}0.3)%, this implies a 90%-confidence-level lower limit on {ital B}({ital D}{sub {ital s}}{sup +}{r arrow}{phi}{pi}{sup +}) of 3.4%.