Chasing after flavor symmetries of quarks from the bottom up

Abstract

AbstractWe explore a flavor structure of quarks in the standard model under the assumption that flavor symmetries exist in a theory beyond the standard model, and seek their properties, using a bottom-up approach. We reacknowledge that a flavor-symmetric part of the Yukawa coupling matrix can be realized by a rank-one matrix, and a democratic-type matrix occupies a special position, based on Dirac’s naturalness.