%0 Journal Article
%T Gravitational footprints of massive neutrinos and lepton number breaking
%A Addazi, A.
%A Marciano, A.
%A Morais, A. P.
%A Pasechnik, R.
%A Srivastava, R.
%A Valle, J. W. F.
%J Physics Letters B
%D 2020
%V 807
%I Elsevier
%@ 0370-2693
%G English
%F Addazi_etal2020
%O WOS:000571765700055
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=4543), last updated on Thu, 08 Oct 2020 08:44:10 +0000
%X We investigate the production of primordial Gravitational Waves (GWs) arising from First Order Phase Transitions (FOPTs) associated to neutrino mass generation in the context of type-I and inverse seesaw schemes. We examine both "high-scale" as well as "low-scale" variants, with either explicit or spontaneously broken lepton number symmetry U(1)(L), in the neutrino sector. In the latter case, a pseudo-Goldstone majoron-like boson may provide a candidate for cosmological dark matter. We find that schemes with softly-broken U(1)(L), and with single Higgs-doublet scalar sector lead to either no FOPTs or too weak FOPTs, precluding the detestability of GWs in present or near future measurements. Nevertheless, we found that, in the majoron-like seesaw scheme with spontaneously broken U(1)(L), at finite temperatures, one can have strong FOPTs and non-trivial primordial GW spectra which can fall well within the frequency and amplitude sensitivity of upcoming experiments, including LISA, BBO and u-DECIGO. However, GWs observability clashes with invisible Higgs decay constraints from the LHC. A simple and consistent fix is to assume the majoron-like mass to lie above the Higgs-decay kinematical threshold. We also found that the majoron-like variant of the low-scale seesaw mechanism implies a different GW spectrum than the one expected in the high-scale seesaw. This feature will be testable in future experiments. Our analysis shows that GWs can provide a new and complementary portal to test the neutrino mass generation mechanism.
%R 10.1016/j.physletb.2020.135577
%U https://arxiv.org/abs/1909.09740
%U https://doi.org/10.1016/j.physletb.2020.135577
%P 135577-8pp