Determination ofB(χcJ→pp¯)in

J. Z. Bai¹,

S. S. Fang²,

H. X. Yang³

et al.

Abstract

The processes (2S)→␥ cJ , cJ →pp (Jϭ0,1,2) are studied using a sample of 14ϫ10 6 (2S) decays collected with the Beijing Spectrometer at the Beijing Electron-Positron Collider. Very clear c0 , c1 and c2 signals are observed, and the branching fractions B( cJ →pp ) (Jϭ0,1,2) are determined to be (27.1 Ϫ3.9 ϩ4.3 Ϯ4.7)ϫ10 Ϫ5 , (5.7 Ϫ1.5 ϩ1.7 Ϯ0.9)ϫ10 Ϫ5 , and (6.5 Ϫ2.1 ϩ2.4 Ϯ1.0)ϫ10 Ϫ5 , respectively, where the first errors are statistical and the second are systematic.