Abstract
We perform a detailed analysis of the one-loop corrections to the light neutrino mass matrix within low scale type I seesaw extensions of the Standard Model and their implications in experimental searches for neutrinoless double beta decay. We show that a sizable contribution to the effective Majorana neutrino mass from the exchange of heavy Majorana neutrinos is always possible, provided one requires a fine-tuned cancellation between the tree-level and one-loop contribution to the light neutrino masses. We quantify the level of fine-tuning as a function of the seesaw parameters and introduce a generalisation of the Casas-Ibarra parametrization of the neutrino Yukawa matrix, which easily allows to include the one-loop corrections to the light neutrino masses.
Highlights
Play a very important role in the type I seesaw scenario
We have performed a systematic analysis of the radiative corrections to the light neutrino masses arising in low scale type I seesaw scenarios, where the RH neutrino masses vary in the interval 100 MeV M 10 TeV
Within this range of masses a significant enhancement of the neutrinoless double beta (0νββ) decay rate in several isotopes - at the level of sensitivity of the present and generation experiments searching for this rare process - is possible, due to the new physics contribution in the decay amplitude given by the exchange of the virtual heavy sterile neutrinos
Summary
(2.5) and (2.10), we recover the usual type I seesaw relation for the (tree-level) light neutrino mass matrix, namely mtνree = −mD MR−1 mTD ≡ −θ∗ MR θ† = −(θ V )∗ M (θ V )† = UP∗MNS m UP†MNS . From figure 1 it is clear that for RH neutrino masses larger than ∼ 1 GeV a considerable enhancement with respect to the naive seesaw scaling of θV is required in order to have a sizable RH neutrino contribution. This enhancement increases with the mass of the RH neutrinos. Similar conclusions are valid for (θV )2min and (θV )2naive in the cases of 0νββ decay of other isotopes (48Ca, 82Se, 130Te, 136Xe, etc.)
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
