Anthropic constraints on fermion masses

TL;DR

This paper reviews how anthropic principles constrain fermion masses, focusing on quark and lepton masses necessary for stable nuclei and complex molecules, highlighting the importance of these constraints in fundamental physics.

Contribution

It synthesizes previous research on anthropic constraints on fermion masses, emphasizing the bounds needed for nuclear stability and complex chemistry.

Findings

Upper bound on lightest lepton mass from electron capture stability

Constraints on quark masses for stable nuclei

Implications for fundamental particle mass ranges

Abstract

We summarize the results of previous research on the constraints imposed on quark masses by the anthropically-motivated requirement that there exist stable nuclei with the right charge to form complex molecules. We also mention an upper bound on the mass of the lightest lepton, derived from the requirement that such nuclei be stable against electron capture.