CP Violating Phenomena and Theoretical Results

Abstract

An introduction to CP violating phenomena is given and the standard model and its most popular low energy extensions are reviewed in this context. The discussion comprises the minimal supersymmetric extension of the standard model, left‐right symmetry, the standard model with more than one Higgs doublet and gauged horizontal symmetries.

SpontaneousCPviolation at the electroweak scale

“…Equations (4) and (5) may also result in potentially unacceptable flavor-changing neutral-Higgs-boson currents. Such currents can be made acceptably small if the explicit breaking parameters are small [12][13][14]. In fact, as we will show, it turns out that the same parameter values which make such a model phenomenologically viable in this context and in observed kaon CP violation allow the model to be a viable candidate for the cosmological mechanism discussed here.…”

“…As long as either £ or <f is nonzero, spontaneous weak-CP nonconservation arises. (Indeed, it is well known that it is only by explicitly breaking the Glashow-Weinberg symmetry that CP can be spontaneously broken in this model [13].) Since weak CP is spontaneously broken, a new kind of domain wall can result, which separates two CP conjugate worlds in the early Universe.…”

Effective action and the quantum equation of motion

“…• Some authors [19] define the parameters in terms of the weak phases of K 0 , K 0 decay amplitudes into isospin…”

Theory of theCP-violating parameterɛ′/ɛ

“…The interested reader may consult (Grimus, 1988;Winstein and Wolfenstein, 1993;Nir, 1997;) for reviews of possible new-physics effects in CP violation.…”