Tim Kretz, "QCD Corrections to Heavy Sterile Neutrino Decays"

jeudi 26 nov. 2026, 11:00 → 12:00 Europe/Paris

210/1-114 - Salle des Séminaires (IJCLab)

Sterile neutrinos $N$ are a compelling extension of the Standard Model and are realised for example, by appending right-handed neutrino fields to the Standard Model; introducing them in this way is referred to as the seesaw mechanism of type I, if a (lepton-number violating) Majorana mass term much larger than the electroweak scale is added to the lagrangian. The interactions of Standard Model particles with (sterile) neutrinos are then governed by a sterile-active mixing matrix element (often simplified to a single mixing angle) $V_{N\ell}$. Standard Model neutrino interactions generally scale with $1-|V_{N\ell}|^2$ while sterile neutrino interactions come with the factor $|V_{N\ell}|^2$. The mixing angles are experimentally constrained to be very small. In this talk I discuss the the effects of hadronic decay modes of sterile neutrinos in the mass range $1~\mathrm{GeV} \lesssim m_N \lesssim 6~\mathrm{GeV}$. It is possible to calculate the fully inclusive hadronic sterile neutrino decay rate using the known Standard Model gauge boson correlators for both the charged-current and the neutral-current up to $\mathcal{O}(\alpha_s^4)$ in the chiral limit as well as their quark mass corrections up to $\mathcal{O}(\alpha_s^3)$ in the charged-current case and $\mathcal{O}(\alpha_s^2)$ in the neutral-current case. The inclusion of the higher-order QCD corrections allows us to find the sterile neutrino mass range in which a perturbative description of hadronic sterile neutrino decays is possible. Within these windows we make predictions for the proper decay length of the sterile neutrino.