Leptonic and semi-leptonic decay modes in Weinberg-Salam-Glashow models

The Weinberg-Salam-Glashow model of leptons and hadrons is described briefly. This model is based on SU(2)xU(1) gauge group with three intermediate vector boson (W+-,Z0) fields and a photon (Aμ) field. Therefore, this model require the existence of a neutral massive intermediate vector boson coupled to leptons and to a strangeness conserving neutral hadron currents. The leptonic process, such as anti νsub(e)+e-→ anti νsub(e)+anti e-, νμ(anti νμ) + e-→νμ(anti νμ) + anti e- are discussed in the W-S-G model. It is found that the W-S-G model explains these processes within certain experimental limits. And then, K0→μanti μ decay mode is also discussed in the context of W-S-G model. This amplitude is found to vanish by what appears to be a fortuitious cancellation between two kinds of diagrams (these of W+- exchange and of induced lambda sub(n) Z coupling). And, with the GIM suppression factor epsilon0 of order 10-3, the weak contribution to K0→μ anti μ would be well within the bounds implied by the experimental data even if the cancellation of the axial vector part were not complete. Leptonic and semi-leptonic decay modes in W-S-G model, therefore, agrees well with the experimental bounds. (author)