Abstract
We report on a search for the radiative decay of Upsilon(1S) to the pseudoscalar mesons eta and eta(') in (21.2 +/- 0.2)x10(6) Upsilon(1S) decays collected with the CLEO III detector at the Cornell Electron Storage Ring. The eta meson was reconstructed in the three modes eta ->gamma gamma, eta ->pi(+)pi(-)pi(0), or eta ->pi(0)pi(0)pi(0). The eta(') meson was reconstructed in the mode eta(')->pi(+)pi(-)eta with eta decaying through any of the above three modes, and also eta(')->gamma rho(0), where rho(0)->pi(+)pi(-). 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 [Upsilon(1S)->gamma eta('), eta(')->pi(+)pi(-)eta, eta ->pi(+)pi(-)pi(0)] there are two good signal candidates, which is insufficient evidence to claim a signal. The other two submodes (eta ->gamma gamma and eta(')->gamma rho) 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(Upsilon(1S)->gamma eta)< 1.0x10(-6) and B(Upsilon(1S)->gamma eta('))< 1.9x10(-6). Our limits are an order of magnitude tighter than the previous ones and below the predictions made by some theoretical models.
Published in:
Physical Review D 76,7 (2007)
Link to original published article:
http://dx.doi.org/10.1103/PhysRevD.76.072003
Keywords
Astronomy & Astrophysics;; Physics, Particles & Fields
Date of Version
January 2007
Recommended Citation
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.; Cronin-Hennessy, D.; Gao, K. Y.; Gong, D. T.; Hietala, J.; Kubota, Y.; Klein, T.; Lang, B. W.; Poling, R.; Scott, A. W.; Smith, A.; Dobbs, S.; Metreveli, Z.; Seth, K. K.; Tomaradze, A.; Zweber, P.; Ernst, J.; Severini, H.; Dytman, S. A.; Love, W.; Savinov, V.; Aquines, O.; Li, Z.; Lopez, A.; Mehrabyan, S.; Mendez, H.; Ramirez, J.; Huang, G. S.; Miller, D. H.; Pavlunin, V.; Sanghi, B.; Shipsey, I. P. J.; Xin, B.; Adams, G. S.; Anderson, M.; Cummings, J. P.; Danko, I.; Napolitano, J.; He, Q.; Insler, J.; Muramatsu, H.; Park, C. S.; Thorndike, E. H.; Coan, T. E.; Gao, Y. S.; Liu, F.; Artuso, M.; Blusk, S.; Butt, J.; Li, J.; Menaa, N.; Mountain, R.; Nisar, S.; Randrianarivony, K.; Redjimi, R.; Sia, R.; Skwarnicki, T.; Stone, S.; Wang, J. C.; Zhang, K.; Csorna, S. E.; Bonvicini, G.; Cinabro, D.; Dubrovin, M.; Lincoln, A.; Asner, D. M.; Edwards, K. W.; Briere, R. A.; Brock, I.; Chen, J.; Ferguson, T.; Tatishvili, G.; Vogel, H.; Watkins, M. E.; Rosner, J. L.; Adam, N. E.; Alexander, J. P.; Berkelman, K.; Cassel, D. G.; Duboscq, J. E.; Ecklund, K. M.; Ehrlich, R.; Fields, L.; Galik, R. S.; Gibbons, L.; Gray, R.; Gray, S. W.; Hartill, D. L.; Heltsley, B. K.; Hertz, D.; Jones, C. D.; Kandaswamy, J.; Kreinick, D. L.; Kuznetsov, V. E.; Mahlke-Krurger, H.; Meyer, T. O.; Onyisi, P. U. E.; Patterson, J. R.; Peterson, D.; Pivarski, J.; Riley, D.; Ryd, A.; Sadoff, A. J.; Schwarthoff, H.; Shi, X.; Stroiney, S.; Sun, W. M.; Wilksen, T.; and Weinberger, M., "Search for radiative decays of Upsilon(1S) into eta and eta'" (2007). Department of Physics and Astronomy Faculty Publications. Paper 792.
https://docs.lib.purdue.edu/physics_articles/792