Gene

Higgs boson

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Gauge (firearms)

Dirac (video compression format)

Particle physics

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Dimension (graph theory)

Bar (unit)

Biochemistry

Neutrino

Standard Model (mathematical formulation)

Physics

Mathematics

Dirac operator

Seesaw molecular geometry

Homogeneous space

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Geometry

Seesaw mechanism

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Repressor

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Operator (biology)

Dark matter

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Physical review. D/Physical review. D.

In this paper, a follow-up of [S. C. Chuli\'a, R. Srivastava, and J. W. F. Valle, Phys. Lett. B 781, 122 (2018)], we describe the many pathways to generate Dirac neutrino mass through dimension-six operators. By using only the standard model Higgs doublet in the external legs, one gets a unique operator $\frac{1}{{\mathrm{\ensuremath{\Lambda}}}^{2}}\overline{L}\overline{\mathrm{\ensuremath{\Phi}}}\overline{\mathrm{\ensuremath{\Phi}}}\mathrm{\ensuremath{\Phi}}{\ensuremath{\nu}}_{R}$. In contrast, the presence of new scalars implies new possible field contractions, which greatly increase the number of possibilities. Here, we study in detail the simplest ones, involving $SU(2{)}_{L}$ singlets, doublets, and triplets. The extra symmetries needed to ensure the Dirac nature of neutrinos can also be responsible for stabilizing dark matter.

Seesaw Dirac neutrino mass through dimension-six operators