Heavy Neutral Leptons via Axionlike Particles at Neutrino Facilities

Journal Article · 24 December 2024 · Physical Review Letters

DOI: https://doi.org/10.1103/PhysRevLett.133.261802 · OSTI ID:2483726

Abdullahi, Asli M. ; de Gouvêa, André ; Dutta, Bhaskar; Shoemaker, Ian M. ; Tabrizi, Zahra

Heavy neutral leptons (HNLs) are often among the hypothetical ingredients behind nonzero neutrino masses. If sufficiently light, they can be produced and detected in fixed-target-like experiments. We show that if the HNLs belong to a richer—but rather generic—dark sector, their production mechanism can deviate dramatically from expectations associated with the standard-model weak interactions. In more detail, we postulate that the dark sector contains an axionlike particle (ALP) that naturally decays into HNLs. Since ALPs mix with the pseudoscalar hadrons, the HNL flux might be predominantly associated with the production of neutral mesons (e.g., ${\pi }^0$ , $\eta$ ) as opposed to charge hadrons (e.g., ${\pi }^{\pm }$ , $K^{\pm }$ ). In this case, the physics responsible for HNL production and decay are not directly related and experiments like DUNE might be sensitive to HNLs that are too weakly coupled to the standard model to be produced via weak interactions, as is generically the case of HNLs that play a direct role in the type-I seesaw mechanism. Published by the American Physical Society 2024

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: National Science Foundation (NSF); State Research Agency (AEI); USDOE; USDOE Office of Science (SC), High Energy Physics (HEP)
• Grant/Contract Number: 89243024CSC000002; AC02-07CH11359; SC0010143; SC0010813; SC0020250; SC0020262
• OSTI ID: 2483726
• Report Number(s): FERMILAB-PUB-23-747-T; IFT-UAM/CSIC--23-145; MI-HET-820; arXiv:2311.07713; 261802
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 26 Vol. 133; ISSN 0031-9007; ISSN PRLTAO
• Publisher: American Physical SocietyCopyright Statement
• Country of Publication: United States
• Language: English