On bottom mixing with exotic quarks

TL;DR

This paper investigates how mixing between bottom quarks and hypothetical exotic quarks affects various asymmetries, decay ratios, and fundamental constants, providing constraints and implications for superstring-inspired models.

Contribution

It offers a comprehensive calculation of bottom-exotic quark mixing effects and derives new bounds based on recent experimental data, including implications for specific grand unified theories.

Findings

Stringent bounds on bottom-exotic quark mixing from data

Impact of exotic quarks on asymmetries and decay ratios

Constraints on superstring-inspired $E_6$ models

Abstract

In this paper we present a calculation of the effects of bottom mixing with new exotic quarks in the forward-backward and left-right asymmetries, the bottom branching ratio and the QCD coupling constant. A global fit with the recent data on these quantities is done and stringent bounds are obtained. We discuss the effects of different isospin signatures for the new possible exotic quarks. The consequences for superstrig-inspired $E_6$ models are discussed. Constraints on the bottom mixing with the isosinglet quarks of the fundamental 27-plet are presented.