Search for radiative decays of {upsilon}(1S) into {eta} and {eta}'

Journal Article · Mon Oct 01 04:00:00 EDT 2007 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.76.072003· OSTI ID:21032304

Athar, S B; Patel, R; Potlia, V; Stoeck, H; Yelton, J ^[1]; Rubin, P ^[2]; Cawlfield, C; Eisenstein, B I; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; White, E J; Wiss, J ^[3]; Shepherd, M R ^[4]; Besson, D ^[5]; Pedlar, T K ^[6]; Cronin-Hennessy, D ^[7]

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1. University of Florida, Gainesville, Florida 32611 (United States)
2. George Mason University, Fairfax, Virginia 22030 (United States)
3. University of Illinois, Urbana-Champaign, Illinois 61801 (United States)
4. Indiana University, Bloomington, Indiana 47405 (United States)
5. University of Kansas, Lawrence, Kansas 66045 (United States)
6. Luther College, Decorah, Iowa 52101 (United States)
7. University of Minnesota, Minneapolis, Minnesota 55455 (United States)

We report on a search for the radiative decay of {upsilon}(1S) to the pseudoscalar mesons {eta} and {eta}{sup '} in (21.2{+-}0.2)x10{sup 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}{yields}{gamma}{gamma}, {eta}{yields}{pi}{sup +}{pi}{sup -}{pi}{sup 0}, or {eta}{yields}{pi}{sup 0}{pi}{sup 0}{pi}{sup 0}. The {eta}{sup '} meson was reconstructed in the mode {eta}{sup '}{yields}{pi}{sup +}{pi}{sup -}{eta} with {eta} decaying through any of the above three modes, and also {eta}{sup '}{yields}{gamma}{rho}{sup 0}, where {rho}{sup 0}{yields}{pi}{sup +}{pi}{sup -}. 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){yields}{gamma}{eta}{sup '}, {eta}{sup '}{yields}{pi}{sup +}{pi}{sup -}{eta}, {eta}{yields}{pi}{sup +}{pi}{sup -}{pi}{sup 0}] there are two good signal candidates, which is insufficient evidence to claim a signal. The other two submodes ({eta}{yields}{gamma}{gamma} and {eta}{sup '}{yields}{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){yields}{gamma}{eta})<1.0x10{sup -6} and B({upsilon}(1S){yields}{gamma}{eta}{sup '})<1.9x10{sup -6}. Our limits are an order of magnitude tighter than the previous ones and below the predictions made by some theoretical models.

• OSTI ID: 21032304
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 7 Vol. 76; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BRANCHING RATIO
CESR STORAGE RING
ELECTRON-POSITRON INTERACTIONS
ELECTRONS
ETA MESONS
ETA PRIME-958 MESONS
MULTIPARTICLE SPECTROMETERS
PARTICLE IDENTIFICATION
PHOTONS
PIONS MINUS
PIONS NEUTRAL
RADIATIVE DECAY
RHO-770 MESONS
UPSILON-9460 MESONS