Abstract
In this work, prospects to probe an overlooked facet of axion-like particles (ALPs) — their potential couplings to sterile neutrinos — are presented. We found that mono-photon searches have the potential to constrain ALP couplings to sterile neutrinos when a new heavy scalar boosts the ALP decay yields. Working within an effective field theory (EFT) approach, we scan the parameters space to establish the reach of the 13 TeV LHC to probe such couplings. We found regions of the parameters space evading several experimental constraints that can be probed at the LHC. Moreover, a complementary role between the LHC and various experiments that search for axions and ALPs can be anticipated for models where ALPs interact with sterile neutrinos. We also present the UV realization of a model having an axion-like particle, a heavy scalar and sterile neutrinos whose parameters are spanned by our EFT approach. The proposed model contains a type of seesaw mechanism for generating masses for the active neutrinos along with sterile neutrinos involving the high energy scale of the spontaneous breaking of the global symmetry associated to the ALP. Some benchmark points of this model can be discovered at the 13 TeV LHC with 300 fb−1.
Highlights
Limit where they vanish, the symmetries are augmented [5]
We found that mono-photon searches have the potential to constrain axion-like particles (ALPs) couplings to sterile neutrinos when a new heavy scalar boosts the ALP decay yields
We present the UV realization of a model having an axion-like particle, a heavy scalar and sterile neutrinos whose parameters are spanned by our effective field theory (EFT) approach
Summary
We parametrize the relevant interactions of the heavy scalar, S, the ALP, a, the sterile neutrino, N , and SM gauge bosons, electrons and muons, with the following effective Lagrangian. In spite of the simplifying assumption of a same new physics scale mediating both S and ALP interactions, the couplings of these new states to these scalars are not necessarily the same Both S and a couplings to the SM particles are supposedly given in terms of the structure and parameters of a complete high energy theory. For mS = 1 TeV fixed, BR(S → aa) drops from nearly 100% for Λ = 100 TeV to a few percent when Λ = 10 TeV This dependence upon the scale Λ helps to soften a bit the drop in the production cross section of ALP pairs shown, especially for large S masses. Let us start discussing the search for signals of the model at the LHC by first evaluating possible constraints to the model
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
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
