Dalitz plot analysis of η[subscript c] → K[superscript +]K[superscript −]η and η[subscript c] → K[superscript +]K[superscript −]π[superscript 0] in two-photon interactions

Abstract

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