Higgs Boson(s) and Rare B Processes : Theoretical Expectations

Abstract

Rare weak processes have always represented a source of sensitive and crucial tests for the Glashow-Weinberg-Salam model of electroweak interactions (hereafter referred to as the standard model, or SM), supplying us, at the same time, with strict guidelines for modelling viable extensions. After the successes linked to Kaon physics, of which the most recent is the first possible observation of “direct” CP violation in K _L,S → ππ decays at CERN [1], the physics of B—mesons opens a window on the structure of the third generation quark sector (for a review on the present status of experimental results see ref. [2]). The discovery of an “anomalously” large EquationSource% MathType!MTEF!2!1!+- % feaagCart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOqamaaBa % aaleaacaWGKbaabeaakiabgkHiTiqadkeagaqeamaaBaaaleaacaWG % Kbaabeaaaaa!3ABB!]]</EquationSource><EquationSource Format="TEX"><![CDATA[$${B_d} - {\bar B_d}$$ mixing, made two years ago by the ARGUS collaboration and subsequently confirmed by the CLEO collaboration, was in this respect quite remarkable. In fact, this has been the first substantial indication in favour of a “heavy” top quark, likely to have a mass above 100 GeV. An indication which is now corroborated by the comparison of the recent precise measurements of the Z ⁰ mass with neutral-current phenomenology data (for a “status of the art” review see ref. [3]).