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Testing the Electroweak Interaction: From PETRA to LEP
Author(s) -
Davier M.
Publication year - 1994
Publication title -
physikalische blätter
Language(s) - English
Resource type - Journals
eISSN - 1521-3722
pISSN - 0031-9279
DOI - 10.1002/phbl.19940500716
Subject(s) - electroweak interaction , physics , particle physics , higgs boson , phenomenology (philosophy) , technicolor , symmetry breaking , electron–positron annihilation , standard model (mathematical formulation) , annihilation , cosmology , theoretical physics , hadron , gauge boson , gauge theory , quantum mechanics , philosophy , epistemology , gauge (firearms) , archaeology , history
Significant progress has been achieved in the last ten years in our understanding of the electroweak interaction. Among the various experimental approaches, e + e − annihilation has played a key role: first at PETRA through the systematic study of Z‐γ interference, then at LEP where the direct observation of Z decays with large statistics allows precise tests to be performed. The results obtained show that (only) three families of (so far) fundamental particles exist in nature. This discovery has profound implications for particle phenomenology, but also for cosmology and the understanding of the universe. Electroweak theory appears to apply universally to the three families, the equality of the electroweak charges being tested to an accuracy of a few per mille. Finally, the precision of the measurements is such that high‐order vacuum polarisation effects in the theory can be measured and the mass of the heavy top quark can be deduced with a precision of 10%. Direct confirmation of this result is underway at FNAL (USA) and will provide a very significant test of the Higgs symmetry‐breaking mechanism.