Dalitz plot analysis of η_c → K^+K^−η and η_c → K^+K^−π^0 in two-photon interactions

We study the processes γγ→K^+K^−η and γγ→K^+K^−π^0 using a data sample of 519 fb^(−1) recorded with the BABAR detector operating at the SLAC PEP-II asymmetric-energy e^+e^− collider at center-of-mass energies at and near the Υ(nS) (n=2,3,4) resonances. We observe η_c→K^+K^−π^0 and η_c→K^+K^−η decays, measure their relative branching fraction, and perform a Dalitz plot analysis for each decay. We observe the K^∗_0(1430)→Kη decay and measure its branching fraction relative to the Kπ decay mode to be R(K^∗_0(1430))=^(B(K^∗_0(1430)→Kη))_(B(K^∗_0(1430)→Kπ))=0.092±0.025^(+0.010)_(−0.025). The η_c→K^+K^−η and K^∗_0(1430)→Kη results correspond to the first observations of these channels. The data also show evidence for η_c(2S)→K^+K^−π^0 and first evidence for η_c(2S)→K^+K^−η