First Measurements of eta_c Decaying into K^+K^-2(pi^+pi^-) and 3(pi^+pi^-)

Abstract

The decays of eta_c to K^+K^-2(pi^+pi^-) and 3(pi^+pi^-) are observed for the first time using a sample of 5.8X10^7 J/ψevents collected by the BESII detector. The product branching fractions are determined to be B(J/ψ-->gamma eta_c)*B(eta_c-->K^+K^-pi^+pi^-pi^+pi^-)=(1.21+-0.32+- 0.23)X10^{-4}$,B(J/\ddot{I}ˆ-->gammaet{a}_c)\ast B(et{a}_c-->K^{\ast 0}{\bar{K}}^{\ast 0}p{i}^{+}p{i}^{-})=(1.29+-0.43+-0.32)X10^{-4}$, and (J/ψ-->gamma eta_c)* B(eta_c-->pi^+pi^-pi^+pi^-pi^+pi^-)= (2.59+-0.32+-0.48)X10^{-4}. The upper limit for eta_c-->phi pi^+pi^-pi^+pi^- is also obtained as B(J/ψ-->gamma eta_c)*B(eta_c--> phi pi^+pi^-pi^+pi^-)< 6.03 X10^{-5} at the 90% confidence level.

11 pages, 4 figures