A Measurement of the Neutral Pion Form Factor by Means of the Reaction π° → e⁺e-.
department or school: Non UBC
data provider: DSpace
contributor: TRIUMF
creator: Gumplinger, Peter
issued: 2019-03-06T17:41:38Z
issued: 1986-11-07
description: The slope parameter "a" of the π° - electromagnetic transition form factor was obtained from a measurement of the partial branching ratio of the Dalitz decay π° → e⁺e- into high invariant-mass electron-positron pairs. The experiment was carried out at the TRIUMF cyclotron laboratory. A beam of π- mesons was stopped in a liquid hydrogen target to produce neutral pions in the reaction π- p → nπ° The electron-positron pairs were detected with two delay-line chamber telescopes, each followed by a large Nal crystal. A third Nal crystal measured the number of π°’s in the target by counting the photons from the decay π°→ y y. Data was taken at three detector opening angles 60°, 130° and 156°. The 60° measurement confirms our normalization. A value a = -0.01 ± 0.035 +0.07, -0.05 where the first error is due to statistics and the second is an estimate of systematic effects, was obtained from the 130° geometry. This value does not support the result of the most recent previous experiment and is in accord with most theoretical calculations indicating that there is no unexpected structure in the π° decay form factor.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/68495
note: I I I I I I I I I I I I I I I I I I I AN ABSTRACT OF THE THESIS OF Peter Gumplinger for the degree of Doctor of Philosophy in Physics presented on November 7, 1986. Title: A Measurement of the Neutral Pion Form Factor by Means of the 0 + -Reaction ,r + e e y. Abstract approved: -------------Albert w. Stetz 0 The slope parameter "a" of the ,r - electromagnetic transition form factor was obtained from a measurement of the partial branching 0 + -ratio of the Dalitz decay ,r + e e y into high invariant-mass electron-positron pairs. The experiment was carried out at the TRIUMF cyclotron laboratory. A beam of ,r- mesons was stopped in a liquid hydrogen target to produce neutral pions in the reaction 0 ,r p + n ,r • The electron-positron pairs were detected with two delay-line chamber telescopes, each followed by a large Nal crystal. A third Nal crystal measured the number of ir 01 s in the target by counting the photons from the decay ir 0 + y y. a • Data was taken at three detector opening angles 60°, 130° and 156°. The 60° measurement confirms our normalization. A value -0.01 ± 0 035 +O.O] where the first error is due to statistics • -0.05' and the second is an estimate of systematic effects, was obtained I I I I I I I I I I I I I I I I I I I 0 from the 130 geometry. This value does not support the result of the most recent previous experiment and is in accord with most theoretical calculations indicating that there is no unexpected structure in then° decay form factor. I I I I I I I I I I I I I I I I I I I A MEASUREMENT OF THE NEUTRAL PION FORM FACTOR BY MEANS OF THE REACTION 'Ir O + e + e - "( by Peter Gumplinger A Thesis submitted to Oregon State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy Completed November 7, 1986 Commencement June 1987 I I I I I I I I I I I I I I I I I I I APPROVED: Professor of Physics in charge of major Chairman of Department of Physics Dean of Graduate School Date thesis is presented November 7 ,…
has type: Thesis/Dissertation
is shown at: 10.14288/1.0376647
language: eng
peer review status: Unreviewed
provider: Vancouver : University of British Columbia Library
publisher: TRIUMF
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/68495