Flavor Phenomenology of Light Dark Vectors

TL;DR

This paper investigates the phenomenology of light dark vectors with flavor-violating couplings, analyzing decay rates of particles and deriving constraints on UV scales, revealing potential for probing very high energy physics.

Contribution

It provides a comprehensive analysis of decay processes involving light dark vectors with flavor violation and derives RGEs to constrain flavor-universal UV scenarios.

Findings

Existing experiments probe UV scales up to 10^{12} GeV.

Decay rates depend on dark vector mass and couplings.

Constraints on flavor violation arise from meson, baryon, and lepton decays.

Abstract

Light dark matter with flavor-violating couplings to fermions may be copiously produced in the laboratory as missing energy from decays of SM particles. Here we study the effective Lagrangian of a light dark vector with generic dipole or vector couplings. We calculate the resulting two-body decay rates of mesons, baryons and leptons as a function of the dark vector mass and show that existing experimental limits probe UV scales as large as $10^{12} \,\mathrm{GeV}$. We also derive the general RGEs in order to constrain the flavor-universal UV scenario, where all flavor violation arises radiatively proportional to the CKM matrix.