Experimental upper limits for the hadronic transitions Υ(2S)→ηΥ(1S) and Υ(2S)→π0Υ(1S)
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Abstract
Using the Crystal Ball detector at thee+e− storage ring DORIS-II, we have searched for the hadronic transitions Υ(2S)→ηΥ(1S) and Υ(2S)→π0Υ(1S) in exclusive decays where the Υ(1S) decays into ane+e− or aµ+µ- pair and the η and π0 are detected by their decay modes η→γγ, η→γγ and π0→γγ. From the number of observed events we derive, after consideration of possible background sources, upper limits on the branching ratiosB(Υ(2S)→ηΥ(1S))<0.7% andB(Υ(2S)→π0Υ(1S))<0.8% at the 90% confidence level.
Keywords
Field Theory Elementary Particle Quantum Field Theory Confidence Level Decay Mode
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References
- 1.L.S. Brown, R.N. Cahn: Phys. Rev. Lett. 35 (1975) 1Google Scholar
- 2.K. Gottfried: Phys. Rev. Lett. 40 (1978) 598Google Scholar
- 3.V. Voloshin: Nucl. Phys. B 154 (1979) 365Google Scholar
- 4.T.-M. Yan: Phys. Rev. D 22 (1980) 1652Google Scholar
- 5.V.A. Novikov, M.A. Shifman: Z. Phys. C — Particles and Fields 8 (1981) 43Google Scholar
- 6.LENA Collab. B. Niczyporuk et al.: Phys. Lett. 100 B (1981) 95; CUSB Collab. G. Mageras et al.: Phys. Rev. Lett. 46 (1981) 1115; CLEO Collab. J. Mueller et al.: Phys. Rev. Lett. 46 (1981) 1181Google Scholar
- 7.CLEO Collab. D. Besson et al.: Phys. Rev. D 30 (1984) 1433Google Scholar
- 8.CUSB Collab. V. Fonseca et al.: Nucl. Phys. B 242 (1984) 31Google Scholar
- 9.ARGUS Collab. H. Albrecht et al.: Phys. Lett. 134 B (1984) 137Google Scholar
- 10.Crystal Ball Collab. D. Gelphman et al.: Phys. Rev. D 32 (1985) 2893Google Scholar
- 11.E.D. Bloom, C.W. Peck: Ann. Rev. Nucl. Part. Sci. 33 (1983) 143; Crystal Ball Collab. M. Oreglia et al.: Phys. Rev. D 25 (1982) 2259Google Scholar
- 12.Crystal Ball Collab. W. Walk et al.: Phys. Rev. D 34 (1986) 2611Google Scholar
- 13.In our previous analysis of the radiative transitions Υ(2S)→γχb→γγ of ref. 12 only the two higher massγγ ll were observed in the γγll final state. Events originating from these two transitions contain a low energy photon in the energy range from 95 MeV to 145 MeV and fall into the indicated kinematic regions of Fig. 1Google Scholar
- 14.Particle Data Group: Review of Particle Properties Phys. Lett. 170 B (1986) 1Google Scholar
- 15.ARGUS Collab. H. Albrecht et al.: DESY 86-169, 1986Google Scholar
- 16.Y.-P. Kuang, T.-M. Yan: Phys. Rev. D 24 (1981) 2874Google Scholar
- 17.M. Voloshin, V. Zakharov: Phys. Rev. Lett. 45 (1980) 688Google Scholar
- 18.G. Segré, J. Weyers: Phys. Lett. 62 B (1976) 91Google Scholar
- 19.H. Genz: Lett. Nuovo Cimento 21 (1978) 270Google Scholar
- 20.P. Langacker: Phys. Lett. 90 B (1980) 447Google Scholar
- 21.B.L. Ioffe, M.A. Shifman: Phys. Lett. 95 B (1980) 99Google Scholar
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