Mass spectrum fitting 120 The Ttnn’ mass spectrum y077 forn’ decaying into > n-ππ m and n→yp Q0-zu>山 60 N,=264±54 obs m=1833.7±6.1±2.7Me BESII Preliminary F=67.7±20.3±77Mep 13 1.5 1.9 23 25 m(t'in)(EvIC B(Jy→Y)B(X→xm)=(22±04±04)×10Mass spectrum fitting Nobs  264  54 m  1833.7  6.1 2.7MeV G  67.7  20.3 7.7MeV 4 ( ) ( ) (2.2 0.4 0.4) 10    B J   X B X        7.7 The +- mass spectrum for  decaying into +- and   BESII Preliminary