Observation of ηc(1S) and ηc(2S) decays to K+K-π+π-π0 in two-photon interactions

• Main Authors: Cowan, Ray Franklin (Contributor), Dujmic, Denis (Contributor), Sciolla, Gabriella (Contributor), Zhao, M. (Contributor)
• Other Authors: Massachusetts Institute of Technology. Laboratory for Nuclear Science (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2011-11-04T19:20:51Z.
• Subjects: Article
• Online Access: Get fulltext

 We study the processes γγ→K[subscript S][superscript 0]K[superscript ±]π[superscript ∓] and γγ→K[superscript +]K[superscript -]π[superscript +]π[superscript -]π[superscript 0] using a data sample of 519.2fb[superscript -1] recorded by the BABAR detector at the PEP-II asymmetric-energy e[superscript +]e[superscript -] collider at center-of-mass energies near the Υ(nS) (n=2, 3, 4) resonances. We observe the η[subscript c](1S), χ[subscript c0](1P) and η[subscript c](2S) resonances produced in two-photon interactions and decaying to K[subscript S][superscript 0]K[superscript ±]π[superscript ∓], with significances of 18.1, 5.4 and 5.3 standard deviations (including systematic errors), respectively, and report 4.0σ evidence of the χ[subscript c2](1P) decay to this final state. We measure the η[subscript c](2S) mass and width in K[subscript S][subscript 0]K[subscript ±]π[subscript ∓] decays, and obtain the values m(η[subscript c](2S))=3638.5±1.5±0.8  MeV/c[superscript 2] and Γ(η[subscript c](2S))=13.4±4.6±3.2  MeV, where the first uncertainty is statistical and the second is systematic. We measure the two-photon width times branching fraction for the reported resonance signals, and search for the χ[subscript c2](2P) resonance, but no significant signal is observed.