Abstract
We discuss higher dimensional effective operators describing interactions between fermionic dark matter and Standard Model particles. They are typically suppressed compared to the leading order effective operators, which can explain why no conclusive direct dark matter detection has been made so far. The ultraviolet completions of the effective operators, which we systematically study, require new particles. These particles can potentially have masses at the TeV scale and can therefore be phenomenologically interesting for LHC physics. We demonstrate that the lowest order options require Higgs-portal interactions generated by dimension six operators. We list all possible tree-level completions with extra fermions and scalars, and we discuss the LHC phenomenology of a specific example with extra heavy fermion doublets.
Highlights
There may be observational implications showing up elsewhere
In the case of DM interactions, the additional suppression of the higher dimensional operators can reduce the cross-section of detection processes even if new physics appears at the TeV scale and the couplings are order unity
An alternative model is that of a feebly interacting massive particle (FIMP) that is produced via a so-called freeze-in mechanism [38]: the particle has initially a low abundance
Summary
In literature these operators are discussed to describe interactions of DM with SM fermions. Operator OH is a dimension five operator describing interactions among DM fermions and the SM Higgs. There exist several possible renormalizable theories which can lead to the same effective operator. In such a fundamental theory new heavy mediator fields are introduced. If they are integrated out, the corresponding effective operator will be generated. For the decomposition of the effective operators, we use the techniques which have been applied to neutrino masses [61, 62], neutrinoless double beta decay [63], and anomalous Higgs couplings [64] before. We discuss the Lorentz structures and decompositions for eq (2.1) and eq (2.2) in the following subsections
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
