ABSTRACT

The electroweak sector of the Standard Model (SM) (for more detailed accounts, see, e.g., [1-3]) grew out of experimental information on chargedcurrent weak interactions, and of the realisation that the four-point Fermi description ceases to be valid above

√ s = 600 GeV [3]. Electroweak theory

was able to predict the existence of neutral-current interactions, as discovered by the Gargamelle Collaboration in 1973 [4]. One of its greatest subsequent successes was the detection in 1983 of the W± and Z0 bosons [5-8], whose existences it had predicted. Over time, thanks to the accumulating experimental evidence, the SU(2)L ⊗ U(1)Y electroweak theory and SU(3)C quantum chromodynamics, collectively known as the Standard Model, have come to be regarded as the correct description of electromagnetic, weak and strong interactions up to the energies that have been probed so far. However, although the SM has many successes, it also has some shortcomings, as discussed in subsequent lectures; see also [9-11].