seesaw mechanism
Recently Published Documents


TOTAL DOCUMENTS

387
(FIVE YEARS 88)

H-INDEX

42
(FIVE YEARS 5)

Author(s):  
Sudhanwa Patra ◽  
Utkarsh Patel ◽  
Purushottam Sahu

The presence of small neutrino masses and flavour mixings can be accounted for naturally in various models about extensions of the standard model, particularly in the seesaw mechanism models. In this work, we present a minimally extended seesaw framework with two right-handed neutrinos, where the active neutrino masses are derived in the radiative regime. Using the framework it can be shown that within certain mass limits, the light neutrino mass term can approach a form that is similar to its form under type-I seesaw mechanism. Apart from this, we show that the decay width of right-handed neutrinos (produced through the decay of [Formula: see text] boson in a particle collider) is short enough to cause a sufficiently long lifetime for the particles, thus ensuring an observable displacement in the LHC between the production and decay vertices. We comment on the fact that these displaced vertex signatures thus can serve as a means to verify the existence of these right-handed neutrinos in future experiments. Lastly, we line up the possibility of our future work where the vertex signatures of particles greater than the mass of [Formula: see text] boson can be worked upon.


2021 ◽  
Vol 81 (12) ◽  
Author(s):  
Tomi Kupiainen ◽  
Anca Tureanu

AbstractWe present a prescription for consistently constructing non-Fock coherent flavour neutrino states within the framework of the seesaw mechanism, and establish that the physical vacuum of massive neutrinos is a condensate of Standard Model massless neutrino states. The coherent states, involving a finite number of massive states, are derived by constructing their creation operator. This construction fulfills automatically the key requirement of coherence for the oscillations of particles to occur. We comment on the inherent non-unitarity of the oscillation probability induced by the requirement of coherence.


2021 ◽  
Vol 81 (12) ◽  
Author(s):  
Nicolás Bernal ◽  
Diego Restrepo

AbstractWe perform a systematic analysis of Standard Model extensions with an additional anomaly-free gauge U(1) symmetry, to generate tree-level Dirac neutrino masses. An anomaly-free symmetry demands nontrivial conditions on the charges of the unavoidable new states. An intensive scan was performed, looking for solutions generating neutrino masses by the type-I and type-II tree-level Dirac seesaw mechanism, via operators with dimension 5 and 6, that correspond to active or dark symmetries. Special attention was paid to the cases featuring no extra massless chiral fermions or multicomponent dark matter with unconditional stability.


2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
B. Fu ◽  
S.F. King

Abstract We consider the possibility that dark matter is stabilised by a discrete Z2 symmetry which arises from a subgroup of a U(1)′ gauge symmetry, spontaneously broken by integer charged scalars, and under which the chiral quarks and leptons do not carry any charges. A chiral fermion χ with half-integer charge is odd under the preserved Z2, and hence becomes a stable dark matter candidate, being produced through couplings to right-handed neutrinos with vector-like U(1)′ charges, as in the type Ib seesaw mechanism. We calculate the relic abundance in such a low energy effective seesaw model containing few parameters, then consider a high energy renormalisable model with a complete fourth family of vector-like fermions, where the chiral quark and lepton masses arise from a seesaw-like mechanism. With the inclusion of the fourth family, the lightest vector-like quark can contribute to the dark matter production, enlarging the allowed parameter space that we explore.


2021 ◽  
Vol 136 (11) ◽  
Author(s):  
A. E. Cárcamo Hernández ◽  
L. T. Hue ◽  
Sergey Kovalenko ◽  
H. N. Long
Keyword(s):  

2021 ◽  
pp. 136764
Author(s):  
João Paulo Pinheiro ◽  
C.A. de S. Pires ◽  
Farinaldo S. Queiroz ◽  
Yoxara S. Villamizar
Keyword(s):  

2021 ◽  
Vol 104 (7) ◽  
Author(s):  
Durmuş Demir ◽  
Canan Karahan ◽  
Ozan Sargın
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document