Loop-induced direct detection signatures from CP-violating scalar mediators

Abstract

We investigate direct detection signatures of dark matter particles interacting with quarks via a light spin-0 mediator with general CP phases. Since tree-level scattering may be strongly suppressed in the non-relativistic limit, loop contributions play an important role and can lead to observable signals in near-future experiments. We study the phenomenology of different mediator masses and CP phases with an emphasis on scenarios with maximal CP violation and Higgs portal models. Intriguingly, the sum of the rates obtained at tree-and loop-level can give a characteristic recoil spectrum not obtainable from a single type of interaction. We furthermore develop a novel method for decomposing the two-loop contribution to effective interactions between dark matter and gluons into two separate one-loop diagrams, which in our case substantially simplifies the calculation of the important top-quark contribution.

Electroweak corrections in a pseudo Nambu-Goldstone Dark Matter model revisited

“…The diagrams in figure 9(a) are calculated using the approach presented in ref. [41] and already applied to the VDM in ref. [29].…”

Invisible and displaced dark matter signatures at Belle II

“…assumes M A mt such that the mediator can be integrated out before the top quark. As pointed out in a different context in Refs [46,47],. this approach may give incorrect results for smaller mediator masses.…”

Comparing 2HDM + scalar and pseudoscalar simplified models at LHC

“…The corresponding cross-section is hence suppressed by the fourth power of the momentum transfer and experimentally relevant only for very light masses of the mediators [20,35,36]. Spin independent DM nucleon interactions, within the reach of, especially, next generation detectors like XENONnT and DARWIN, emerge however at the one loop level [20,21,[37][38][39] (see also [19,40]).…”