Search for X ( 3872 ) → π + π - π 0 at Belle
We present a search for the decay X(3872) → π + π - π 0 in the (772 ±11) ×10 6 Y(4S)→B$\overline{B}$ data sample collected at the Belle detector, where the X(3872) is produced in B ± → K ± X(3872) and B 0 →K$^{0}_{S}$X(3872) decays. We do not observe a signal, and set 90% credible upper limits for two different models of the decay processes: if the decay products are distributed uniformly in phase space, $\mathscr{B}$(X(3872) → π + π - π 0 )<1.3%, and if M(π + π - ) is concentrated near the mass of the D 0 $\overline{D}$ 0 pair in the process X(3872) → D 0 $\overline{D}$ *0 + c.c. → D 0 $\overline{D}$ 0 π 0 → π + π - π 0 , $\mathscr{B}$(X(3872) → π + π - π 0 )<1.2×10 -3 .