Flavored dark matter beyond Minimal Flavor Violation

TL;DR

This paper explores a new framework called Dark Minimal Flavor Violation (DMFV) that links flavor physics and dark matter stability, analyzing a specific Dirac fermionic dark matter model with flavor-safe coupling structures and collider constraints.

Contribution

It introduces the DMFV framework allowing arbitrary flavor structures in dark matter couplings, and studies its implications for dark matter stability and collider phenomenology beyond Minimal Flavor Violation.

Findings

Identification of flavor-safe coupling scenarios beyond MFV

Constraints on parameter space from flavor and collider data

Relevance of LHC monojet searches for compressed spectra

Abstract

We study the interplay of flavor and dark matter phenomenology for models of flavored dark matter interacting with quarks. We allow an arbitrary flavor structure in the coupling of dark matter with quarks. This coupling is assumed to be the only new source of violation of the Standard Model flavor symmetry extended by a $U(3)_\chi$ associated with the dark matter. We call this ansatz Dark Minimal Flavor Violation (DMFV) and highlight its various implications, including an unbroken discrete symmetry that can stabilize the dark matter. As an illustration we study a Dirac fermionic dark matter $\chi$ which transforms as triplet under $U(3)_\chi$, and is a singlet under the Standard Model. The dark matter couples to right-handed down-type quarks via a colored scalar mediator $\phi$ with a coupling $\lambda$. We identify a number of "flavor-safe" scenarios for the structure of $\lambda$ which are beyond Minimal Flavor Violation. For dark matter and collider phenomenology we focus on the well-motivated case of $b$-flavored dark matter. The combined flavor and dark matter constraints on the parameter space of $\lambda$ turn out to be interesting intersections of the individual ones. LHC constraints on simplified models of squarks and sbottoms can be adapted to our case, and monojet searches can be relevant if the spectrum is compressed.