We consider models where a massive spin-two resonance acts as the mediator between Dark Matter (DM) and the SM particles through the energy-momentum tensor. We examine the effective theory for fermion, vector and scalar DM generated in these models and find novel types of DM-SM interaction never considered before. We identify the effective interactions between DM and the SM quarks when the mediator is integrated out, and match them to the gravitational form factors relevant for spin-independent DM-nucleon scattering. We also discuss the interplay between DM relic density conditions, direct detection bounds and collider searches for the spin-two mediator.

In a version of the PA-2HDM where only mixing between third and second fermion generations is allowed, we propose a mechanism to generate the second Yukawa matrix through a Unitary V-spin flavor transformation on the mass matrix for quarks and leptons. This flavor structure is constrained to be universal, that is, we use the same parameters to generate Yukawa matrix elements in the quark and leptonic sectors, reducing drastically the number of free parameters of the PA-2HDM. As a consequence of this restrictive condition, we obtain relations between the Yukawa matrix elements, that we call the Universal Texture Constraint (UTC). We obtained an interval of values for the second Yukawa matrix elements, expressed in terms of the Cheng and Sher ansatz, for [Formula: see text] and [Formula: see text] coming from the UTC and experimental bounds for light scalar masses. Finally, we find the allowed parameter region when the experimental bounds and values for [Formula: see text] decays, [Formula: see text] mixing, [Formula: see text] and [Formula: see text] are considered.

August 27, 2019 1:56 WSPC/INSTRUCTION FILE paper˙IJPA˙to˙arXiv 2 Carrillo-Monteverde et.al for leptonic decay of mesons with FCNC and LFV.

We propose a new mechanism for making dark matter self-interacting in the presence of a massive spin-2 mediator. The derived Yukawa-type potential for dark matter is independent of the spins of dark matter, so are the resulting Sommerfeld effects for the dark matter self-scattering. We find that both the Born cross section and relatively mild Sommerfeld effects assist to make the self-scattering cross section velocity-dependent. We discuss how to evade the current indirect bounds on dark matter annihilations and show that the model is marginally compatible with perturbative unitarity in the ghost-free realization of the massive spin-2 particle.

We consider models where a massive spin-two resonance acts as the mediator between Dark Matter (DM) and the SM particles through the energy-momentum tensor. We examine the effective theory for fermion, vector and scalar DM generated in these models and find novel types of DM-SM interaction never considered before. We identify the effective interactions between DM and the SM quarks when the mediator is integrated out, and match them to the gravitational form factors relevant for spin-independent DM-nucleon scattering. We also discuss the interplay between DM relic density conditions, direct detection bounds and collider searches for the spin-two mediator.