Book contents
- Frontmatter
- Contents
- Epigraph
- Preface
- Dedication
- 1 Introduction
- 2 Historical perspectives
- 3 μSR techniques
- 4 Analysis and interpretation of μSR data
- 5 Some comparisons of μSR with other techniques
- 6 Muon reactivity and muonium formation
- 7 Muonium reactions in gases
- 8 Muonium reactions in solution
- 9 Free radicals containing muons
- 10 Muonic atoms – the chemistry of μ−
- 11 Concluding chapter
- Appendix
- Index
- Frontmatter
- Contents
- Epigraph
- Preface
- Dedication
- 1 Introduction
- 2 Historical perspectives
- 3 μSR techniques
- 4 Analysis and interpretation of μSR data
- 5 Some comparisons of μSR with other techniques
- 6 Muon reactivity and muonium formation
- 7 Muonium reactions in gases
- 8 Muonium reactions in solution
- 9 Free radicals containing muons
- 10 Muonic atoms – the chemistry of μ−
- 11 Concluding chapter
- Appendix
- Index
Summary
Although a muon exists for only two millionths of a second, this is time enough for it to participate in many of the fundamental chemical processes available to stable charged particles. One can produce either positive or negative muons, and since they have a mass intermediate between that of the proton and the electron, it is not surprising that the positive muon tends to behave as if it were a light proton, while the negative muon behaves as if it were a heavy electron.
Muons
Muons (μ) are elementary particles of the lepton family which occur, transiently, as part of the natural decay scheme of pions (μ), as indicated by the overall sequence in Eq. [1.1].
Their origin and occurrence, therefore, require a source of pions. These are the lightest and commonest of the mesons, but they appear in nature extremely rarely, only when cosmic particles interact with the atmosphere. However, pions are readily created in one of three charge states (π+, π− or π∘) during high-energy nuclear collisions. This is because nuclear glue can be thought of as the exchange of ‘virtual’ pions between nucleons, so that the production of pions outside the nucleus can occur when a nuclear collision exceeds the rest mass of a pion (0.15 amu, or 140 MeV). Consequently, copious fluxes of pions are manufactured at targets in the beams of the world's several accelerators capable of producing protons at energies much greater than 140 MeV. When the short-lived positive or negative pion decays it creates an energetic muon of the same charge. The muon lives for 2.2 μS, on average, before decaying to an energetic electron of the same charge.
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- Chapter
- Information
- Muon and Muonium Chemistry , pp. 1 - 9Publisher: Cambridge University PressPrint publication year: 1983