Observation of the decay ψ(2S)→K∗(892)K¯+c.c.

Abstract Using 14 million ψ ( 2 S ) events collected with the BESII detector, branching fractions of ψ ( 2 S ) → K ∗ ( 892 ) + K − + c.c. and K ∗ ( 892 ) 0 K ¯ 0 + c.c. are determined to be: B ( ψ ( 2 S ) → K ∗ ( 892 ) + K − + c.c. ) = ( 2.9 −1.7 +1.3 ± 0.4 ) × 10 −5 and B ( ψ ( 2 S ) → K ∗ ( 892 ) 0 K ¯ 0 + c.c. ) = ( 13.3 −2.7 +2.4 ± 1.7 ) × 10 −5 . The results confirm the violation of the “12% rule” for these two decay channels. A large isospin violation between the charged and neutral modes is observed.