Results concerning the decay Ds±→η′π±

Abstract A search for the decay D s + →η′π + ;η′→ϱγ has been performed by the NA14/2 photoproduction experiment at CERN. A signal compatible with the D s + has been observed, leading to a ratio of branching fractions of Br ( D s + →η′π + ) Br ( D s + →φπ + )=2.5±1.0 -0.4 +1.5 . A value of Br ( D + →η′π + ) Br ( D + → K − π + π + ) is set at 90% CL.