481 research outputs found
Flat Higgs Potential from Planck Scale Supersymmetry Breaking
The observed Higgs boson mass poses a new puzzle in addition to the
longstanding problem of the origin of the electroweak scale; the shallowness of
the Higgs potential. The Higgs quartic coupling even seems to vanish at around
the Planck scale within the uncertainties of the top quark mass and the strong
gauge coupling. We show that the shallowness of the Higgs potential might be an
outcome of supersymmetry breaking at around the Planck scale. There, the
electroweak fine-tuning in the Higgs quadratic terms leads to an almost
vanishing quartic coupling at around the Planck scale.Comment: 4 pages, 2 figure
Why three generations?
We discuss an anthropic explanation of why there exist three generations of
fermions. If one assumes that the right-handed neutrino sector is responsible
for both the matter-antimatter asymmetry and the dark matter, then anthropic
selection favors three or more families of fermions. For successful
leptogenesis, at least two right-handed neutrinos are needed, while the third
right-handed neutrino is invoked to play the role of dark matter. The number of
the right-handed neutrinos is tied to the number of generations by the anomaly
constraints of the gauge symmetry. Combining anthropic arguments
with observational constraints, we obtain predictions for the -ray
observations, as well as for neutrinoless double-beta decay.Comment: 7pages, 2 figure
Revisiting the Minimal Chaotic Inflation Model
We point out that the prediction of the minimal chaotic inflation model is
altered if a scalar field takes a large field value close to the Planck scale
during inflation due to a negative Hubble induced mass. In particular, we show
that the inflaton potential is effectively suppressed at a large inflaton field
value in the presence of such a scalar field. The scalar field may be
identified with the standard model Higgs field or flat directions in
supersymmetric theory. With such spontaneous suppression, we find that the
minimal chaotic inflation model, especially the model with a quadratic
potential, is consistent with recent observations of the cosmic microwave
background fluctuation without modifying the inflation model itself.Comment: 5 pages, 3 figure
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