Book contents
- Frontmatter
- Contents
- Preface
- I Inputs to the Standard Model
- II Interactions of the Standard Model
- III Symmetries and anomalies
- IV Introduction to effective lagrangians
- V Leptons
- VI Very low energy QCD – pions and photons
- VII Introducing kaons and etas
- VIII Kaons and the ΔS = 1 interaction
- IX Kaon mixing and CP violation
- X The Nc-1 expansion
- XI Phenomenological models
- XII Baryon properties
- XIII Hadron spectroscopy
- XIV Weak interactions of heavy quarks
- XV The Higgs boson
- XVI The electroweak gauge bosons
- A Appendix – Functional integration
- B Appendix – Some field theoretic methods
- C Appendix – Useful formulae
- References
- Index
XV - The Higgs boson
Published online by Cambridge University Press: 06 January 2010
- Frontmatter
- Contents
- Preface
- I Inputs to the Standard Model
- II Interactions of the Standard Model
- III Symmetries and anomalies
- IV Introduction to effective lagrangians
- V Leptons
- VI Very low energy QCD – pions and photons
- VII Introducing kaons and etas
- VIII Kaons and the ΔS = 1 interaction
- IX Kaon mixing and CP violation
- X The Nc-1 expansion
- XI Phenomenological models
- XII Baryon properties
- XIII Hadron spectroscopy
- XIV Weak interactions of heavy quarks
- XV The Higgs boson
- XVI The electroweak gauge bosons
- A Appendix – Functional integration
- B Appendix – Some field theoretic methods
- C Appendix – Useful formulae
- References
- Index
Summary
A central feature of the Standard Model is the spontaneous symmetry breaking in the electroweak sector which gives mass to fermions and to the W± and Z0 gauge bosons. The sole physical remnant of this process is the Higgs boson. Although its couplings to the other particles in the theory are fully specified, the Higgs mass is undetermined. As a consequence, efforts to detect this particle cover the widest possible range of mass values [GuHKD 90, Ei 91].
Mass and couplings of the Higgs boson
Although a complex doublet of Higgs fields is initially introduced in the Weinberg–Salam model, there remains following spontaneous symmetry breaking precisely one physical Higgs state, a neutral scalar particle H0. That is, if we define the number of degrees of freedom for Higgs and gauge boson states respectively as NH and NG, then before the symmetry breaking we have NH = 4, NG = 8 whereas afterwards we find NH = 1, NG = 11. To obtain these values, recall that massive vector particles have three spin components whereas massless vector particles have just two. Although the total of Higgs and gauge-boson degrees of freedom remains fixed (NH + NG = 12), there is a transfer of three states from the Higgs sector to the gauge-boson sector. These Higgs states become the longitudinal spin modes of the W±, Z0 particles.
- Type
- Chapter
- Information
- Dynamics of the Standard Model , pp. 415 - 429Publisher: Cambridge University PressPrint publication year: 1992