751 research outputs found
Landscape Predictions for the Higgs Boson and Top Quark Masses
If the Standard Model is valid up to scales near the Planck mass, and if the
cosmological constant and Higgs mass parameters scan on a landscape of vacua,
it is well known that the observed orders of magnitude of these quantities can
be understood from environmental selection for large-scale structure and atoms.
If in addition the Higgs quartic coupling scans, with a probability
distribution peaked at low values, environmental selection for a phase having a
scale of electroweak symmetry breaking much less than the Planck scale leads to
a most probable Higgs mass of 106 GeV. While fluctuations below this are
negligible, the upward fluctuation is 25/p GeV, where p measures the strength
of the peaking of the a priori distribution of the quartic coupling. If the top
Yukawa coupling also scans, the most probable top quark mass is predicted to
lie in the range (174--178) GeV, providing the standard model is valid to at
least 10^{17} GeV. The downward fluctuation is 35 GeV/ \sqrt{p}, suggesting
that p is sufficiently large to give a very precise Higgs mass prediction.
While a high reheat temperature after inflation could raise the most probable
value of the Higgs mass to 118 GeV, maintaining the successful top prediction
suggests that reheating is limited to about 10^8 GeV, and that the most
probable value of the Higgs mass remains at 106 GeV. If all Yukawa couplings
scan, then the e,u,d and t masses are understood to be outliers having extreme
values induced by the pressures of strong environmental selection, while the s,
\mu, c, b, \tau Yukawa couplings span only two orders of magnitude, reflecting
an a priori distribution peaked around 10^{-3}. Extensions of these ideas allow
order of magnitude predictions for neutrino masses, the baryon asymmetry and
important parameters of cosmological inflation.Comment: 41 pages; v4: threshold corrrections for top Yukawa are correcte
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