Speaker
J. David Van Horn
(University of Missouri-Kansas City)
Description
Asymmetry is a basic property found at multiple scales in the universe [1]. Asymmetric molecular interactions are fundamental to the operation of biological systems in both signaling and structural roles. Other aspects asymmetry are observed and useful in many areas of science and engineering and have been studied since the discovery of chirality in tartrate salts [2]. The observation of parity violation in beta decay [3, 4] provided some impetus for later experiments using asymmetric particles. Here we survey historical work and experiments related to positron interactions with asymmetric materials in gas liquid and solid forms.
Asymmetric interactions may be classified as: 1) stereorecognition, 2) stereoselection and 3) stereoinduction [1]. These three facets of physical stereochemistry are unique but interrelated; examples from chemistry and materials science will be given for illustrative purposes. Experimental positron and electron interactions with asymmetric materials may be classified in like manner. Thus, a qualitative assessment of helical and polarized positron experiments with different forms of asymmetric matter from the past 40 years will be presented, as well as recent experiments with left-hand and right-hand single crystal quartz [5] and organic compounds.
The purpose of this classification and review is to evaluate the field for potential new experiments and directions for positron (or electron) studies with asymmetric materials; future directions in bulk and beam positron asymmetric experiments will be discussed.
[1] J. M. Hicks, Ed., “Chirality: Physical Chemistry.” Am. Chem. Soc., Washington, DC, 2002.
[2] L. Pasteur, CR Hebd. Acad. Sci., 26, 535 (1848).
[3] C. S. Wu, E. Ambler, R. W. Hayward, D. D. Hoppes, and R. P. Hudson, Phys. Rev. 105, 1413 (1957).
[4] R. L. Garwin, L. M. Lederman and M. Weinrich, Phys. Rev. 105, 1415 (1957).
[5] J. D. Van Horn, F. Wu, G. Corsiglia and Y. C. Jean, Def. Diffus. Forum, 373, 221 (2016).
Primary author
J. David Van Horn
(University of Missouri-Kansas City)
Co-authors
Mr
Fei Wu
(University of Missouri-Kansas City)
Prof.
Y. C. Jean
(University of Missouri-Kansas City)
