Search for radiative decays of Υ(1S) into η and η′

S. B. Athar, R. Patel, V. Potlia, H. Stoeck, J. Yelton, P. Rubin, C. Cawlfield, B. I. Eisenstein, I. Karliner, D. Kim, N. Lowrey, P. Naik, C. Sedlack, M. Selen, E. J. White, J. Wiss, M. R. Shepherd, D. Besson, T. K. Pedlar, D. Cronin-HennessyK. Y. Gao, D. T. Gong, J. Hietala, Y. Kubota, T. Klein, B. W. Lang, R. Poling, A. W. Scott, A. Smith, S. Dobbs, Z. Metreveli, K. K. Seth, A. Tomaradze, P. Zweber, J. Ernst, H. Severini, S. A. Dytman, W. Love, V. Savinov, O. Aquines, Z. Li, A. Lopez, S. Mehrabyan, H. Mendez, J. Ramirez, G. S. Huang, D. H. Miller, V. Pavlunin, B. Sanghi, I. P J Shipsey, B. Xin, G. S. Adams, M. Anderson, J. P. Cummings, I. Danko, J. Napolitano, Q. He, J. Insler, H. Muramatsu, C. S. Park, E. H. Thorndike, T. E. Coan, Y. S. Gao, F. Liu, Marina Artuso, Steven Roy Blusk, J. Butt, J. Li, N. Menaa, R. Mountain, S. Nisar, K. Randrianarivony, R. Redjimi, R. Sia, Tomasz Skwarnicki, Sheldon Stone, J. C. Wang, K. Zhang, S. E. Csorna, G. Bonvicini, D. Cinabro, M. Dubrovin, A. Lincoln, D. M. Asner, K. W. Edwards, R. A. Briere, I. Brock, J. Chen, T. Ferguson, G. Tatishvili, H. Vogel, M. E. Watkins, J. L. Rosner, N. E. Adam, J. P. Alexander, K. Berkelman, D. G. Cassel, J. E. Duboscq, K. M. Ecklund, R. Ehrlich, L. Fields, R. S. Galik, L. Gibbons, R. Gray, S. W. Gray, D. L. Hartill, B. K. Heltsley, D. Hertz, C. D. Jones, J. Kandaswamy, D. L. Kreinick, V. E. Kuznetsov, H. Mahlke-Krüger, T. O. Meyer, P. U E Onyisi, J. R. Patterson, D. Peterson, J. Pivarski, D. Riley, A. Ryd, A. J. Sadoff, H. Schwarthoff, X. Shi, S. Stroiney, W. M. Sun, T. Wilksen, M. Weinberger

Research output: Contribution to journalArticle

10 Scopus citations


We report on a search for the radiative decay of Υ(1S) to the pseudoscalar mesons η and η′ in (21.2±0.2)×106 Υ(1S) decays collected with the CLEO III detector at the Cornell Electron Storage Ring. The η meson was reconstructed in the three modes η→γγ, η→π+π-π0, or η→π0π 0π0. The η′ meson was reconstructed in the mode η′→π+π-η with η decaying through any of the above three modes, and also η′→γρ0, where ρ0→π+π-. Five out of the seven submodes are found to have very low backgrounds. In four of them we find no signal candidates and in one [Υ(1S)→γη′, η′→π+π-η, η→π+π-π0] there are two good signal candidates, which is insufficient evidence to claim a signal. The other two submodes (η→γγ and η′→γρ) are background limited, and show no excess of events in their signal regions. We combine the results from different channels and obtain upper limits at the 90% C.L. which are B(Υ(1S)→γη)<1.0×10-6 and B(Υ(1S) →γη′)<1.9×10-6. Our limits are an order of magnitude tighter than the previous ones and below the predictions made by some theoretical models.

Original languageEnglish (US)
Article number072003
JournalPhysical Review D
Issue number7
StatePublished - Oct 11 2007


ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Nuclear and High Energy Physics
  • Mathematical Physics

Cite this

Athar, S. B., Patel, R., Potlia, V., Stoeck, H., Yelton, J., Rubin, P., Cawlfield, C., Eisenstein, B. I., Karliner, I., Kim, D., Lowrey, N., Naik, P., Sedlack, C., Selen, M., White, E. J., Wiss, J., Shepherd, M. R., Besson, D., Pedlar, T. K., ... Weinberger, M. (2007). Search for radiative decays of Υ(1S) into η and η′. Physical Review D, 76(7), [072003].