Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electroweak naturalness in three-flavour Type I see-saw and implications
  for leptogenesis   In the Type I see-saw model, the naturalness requirement that corrections to
the electroweak $\mu$ parameter not exceed 1 TeV results in a rough bound on
the lightest right-handed neutrino mass, $M_{N_1}\lesssim 3\times 10^7$ GeV. In
this letter we derive generic bounds applicable in any three-flavour Type I
see-saw model. We find $M_{N_1}\lesssim 4\times 10^7$ GeV and $M_{N_2}\lesssim
7\times 10^7$ GeV. In the limit of one massless neutrino, there is no
naturalness bound on $M_{N_3}$ in the Poincare protected decoupling limit. Our
results confirm that no Type I see-saw model can explain the observed neutrino
masses and baryogenesis via hierarchical ($N_1$-, $N_2$-, or $N_3$-dominated)
thermal leptogenesis while remaining completely natural.

9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th