Observation of Eta-C and Other Structures in the Radiative Decay Psi to Gamma Eta Negative Pion Positive Pion

Becker, Jeffrey Jay

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Description

Title

Observation of Eta-C and Other Structures in the Radiative Decay Psi to Gamma Eta Negative Pion Positive Pion

Author(s)

Becker, Jeffrey Jay

Issue Date

1984

Department of Study

Physics

Discipline

Physics

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

Physics, Elementary Particles and High Energy

Language

eng

Abstract

The Mark III detector at SPEAR was used to observe the exclusive radiative decay (psi) (--->) (gamma)(eta)(pi)('+)(pi)('-). The (eta)(,c) was seen as an intermediate state in this decay, (psi) (--->) (gamma)(eta)(,c), (eta)(,c) (--->) (eta)(pi)('+)(pi)('-). The product branching ratio B((psi) (--->) (gamma)(eta)(,c)) B((eta)(,c) (--->) (eta)(pi)('+)(pi)('-)) was measured to be 4.2 (+OR-) 0.5 (stat) (+OR-) 0.5 (sys) x 10('-4). Other resonant structure was observed in the (eta)(pi)('+)(pi)('-) spectrum in the range 1 ) (delta)('(+OR-))(pi)('(-OR+)), (delta)('(+OR-)) (--->) (eta)(pi)('(+OR-)). A spin-parity analysis was performed to determine the quantum numbers of the resonances responsible for this structure. However, the result was seen to be model dependent, so that it was not possible to conclusively resolve the underlying structure in the spectrum. No evidence was seen for the decay (iota) (--->) (eta)(pi)('+)(pi)('-). An upper limit was set for the ratio of branching ratios for (iota) (--->) (eta)(pi)(pi) relative to (iota) (--->) KK(pi), R = (B((psi)(--->) (gamma)(iota)) B((iota)(--->) (eta)(pi)(pi)))/(B((psi)(--->) (gamma)(iota)) B((iota)(--->) KK(pi))) < 0.2 (90% C.L.).

Graduation Semester

1984

Type of Resource

text

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