Book contents
- Frontmatter
- Contents
- Foreword
- Unification of fundamental forces
- 1 Introduction
- 2 The unifying concepts of physics in the past
- 3 The concept of elementarity and nuclear forces
- 4 The unification of the weak nuclear force with electromagnetism
- 5 The strong nuclear force as a gauge force and the standard model
- 6 Beyond the standard model
- 7 Envoi
- History unfolding: an introduction to the two 1968 lectures by W. Heisenberg and P. A. M. Dirac
- Theory, criticism, and a philosophy
- Methods in theoretical physics
6 - Beyond the standard model
Published online by Cambridge University Press: 08 January 2010
- Frontmatter
- Contents
- Foreword
- Unification of fundamental forces
- 1 Introduction
- 2 The unifying concepts of physics in the past
- 3 The concept of elementarity and nuclear forces
- 4 The unification of the weak nuclear force with electromagnetism
- 5 The strong nuclear force as a gauge force and the standard model
- 6 Beyond the standard model
- 7 Envoi
- History unfolding: an introduction to the two 1968 lectures by W. Heisenberg and P. A. M. Dirac
- Theory, criticism, and a philosophy
- Methods in theoretical physics
Summary
What are the ideas beyond the Standard Model which may extend it?
The prime idea relates to what is called supersymmetry. This is a symmetry that is postulated to exist between spin-0 and spin-1/2, or spin-l and spin-1/2, or spin-2 and spin-3/2.
As stated before, particles with integer intrinsic spins (0, 1ħ, 2ħ, 3ħ, … etc.) are called bosons, and those with half-integer intrinsic spins ħ/2, 3ħ/2 etc. are called fermions. Bosons and fermions are thought to be very different objects – the fermions are individualists, the bosons are collectivist – but supersymmetry can relate them in a precise way. At one stroke, supersymmetry would double the number of objects so far as the Standard Model is concerned. Thus, in addition to W+, W-, Z0 and γ, there would exist their spin-half partners (called Winos, Zinos and photinos) plus spin-zero friends of quarks and leptons, the so-called squarks and sleptons (unspeakable names).
Supersymmetry is a beautiful notion. It diminishes considerably Dirac's infinities and inconsistencies, though it does not eliminate them completely.
- Type
- Chapter
- Information
- Unification of Fundamental ForcesThe First 1988 Dirac Memorial Lecture, pp. 63 - 79Publisher: Cambridge University PressPrint publication year: 1990