FCNC portals to the dark sector

Abstract

Abstract:The most general basis of operators parametrizing a low-scale departure from the SM particle content is constructed. The SM gauge invariance is enforced, and operators of lowest dimensions are retained separately for a new light neutral particle of spin 0, 1/2, 1, and 3/2. The basis is further decomposed into couplings to the SM Higgs/gauge fields, to pairs of quark/lepton fields, and to baryon/lepton number violating combinations of fermion fields. This basis is then used to systematically investigate the discovery potential of the rare FCNC decays of the K and B mesons with missing energy in the final state. The most sensitive decay modes in the s → d, b → d, and b → s sectors are identified and compared for each type of couplings to the new invisible state.

Minimal axion model from flavor

“…where m K;π are the kaon and pion masses, and B s ¼ 4.6ð8Þ is the nonperturbative parameter related to the quark condensate [42]. The 90% C.L.…”

Dark matter within the minimal flavour violation ansatz

“…[72,73]). The operators above correspond to an effective theory description of the NP sector giving rise to an additional sources of quark-DM coupling besides the Higgs portal interactions.…”

Classification of effective operators for interactions between the Standard Model and dark matter

“…After completing this paper we have learned about the papers [39,40], where the operator basis for interactions between the Standard Model and dark matter had been also constructed. Assumptions made here and in [39,40] were different. The operators in [39,40] agree with ours whenever the assumptions and field content in both papers coincide.…”

“…Assumptions made here and in [39,40] were different. The operators in [39,40] agree with ours whenever the assumptions and field content in both papers coincide.…”