February 28, 2018 to March 2, 2018
Aachen
Europe/Zurich timezone

On the Hierarchy Problem and the Cosmological Constant Problem in the Standard Model

Feb 28, 2018, 2:30 PM
40m

Speaker

Fred Jegerlehner (DESY Zeuthen/Humboldt Univ. Berlin)

Description

I argue that the SM in the Higgs phase does not suffer form a
hierarchy problem'' and that similarly thecosmological constant
problem'' resolves itself if we understand the SM as a low energy
effective theory emerging from a cut-off medium at the Planck scale.
We discuss these issues under the condition of a stable Higgs vacuum,
which allows to extend the SM up to the Planck length. The bare Higgs
boson mass then changes sign below the Planck scale, such the the SM
in the early universe is in the symmetric phase. The cut-off enhanced
Higgs mass term as well as the quartically enhanced cosmological
constant term trigger the inflation of the early universe. Reheating
follows by the heavy Higgses decaying predominantly into top--anti-top
pairs, which at this stage are effectively massless. The coefficients
of the shift between bare and renormalized Higgs mass as well as of
the shift between bare and renormalized vacuum energy density exhibit
close-by zeros at about $10^{15}~$GeV. The scale dependent Higgs mass
counter term is negative in the Higgs phase (low energy), which
triggers the electroweak phase transition, and changes sign at the
transition point after which is is large positive, which turns the
system into the symmetric phase at high energies. Obviously, the SM
Higgs system initially provides a huge \textbf{dark energy} density
and the resulting inflation is taming the originally huge cosmological
constant to the small value observed today, whatever its initial value
was, provided it was large enough to trigger inflation. While
laboratory experiments can access physics of the broken phase only,
the symmetric phase above the Higgs transition point is accessible
though physics of the early universe as it manifests in cosmological
observations. The main unsolved problem remains the origin of dark
matter.

Primary author

Fred Jegerlehner (DESY Zeuthen/Humboldt Univ. Berlin)

Presentation materials