Research Group Prof. Krämer
Research Topics
The Large Hadron Collider (LHC) at CERN is the flagship research facility of
particle physics for the next decade. After the discovery of a Higgs-particle in
the first phase of the LHC in 2012, the key scientific goal for the second
phase, starting in 2015, is to search for and explore physics beyond the
Standard Model (SM). The existence of new physics at the Tera-electronvolt
(TeV) scale, i.e. in reach of the LHC, is motivated by two fundamental questions
left unanswered by the SM: the hierarchy problem and the nature of dark matter.
The hierarchy problem refers to the instability of the Higgs mass at the
electroweak scale under quantum fluctuations originating from higher scale
physics. It can be solved, for example, through new TeV-scale particles
partnering the SM top quark. Dark matter, on the other hand, is explained
naturally by stable, weakly interacting particles with masses near the TeV
scale. Such particles are predicted in many extensions of the SM, which attempt
to solve the hierarchy problem, like supersymmetry or models with extra space
dimensions. At the LHC, such new physics can be searched for either directly,
for example in signatures with a transverse momentum imbalance caused by
escaping dark matter particles, or through precisions studies which attempt to
establish deviations from the SM in a global theoretical analysis of all
existing experimental observables, including in particular the Higgs sector.
A fascinating aspect of the search for new physics is the interplay between LHC
physics and astrophysical observations. Dark matter particles may not only be
produced and detected at the LHC, but they also leave traces in cosmic rays
and maybe observed in nuclear reactions in highly sensitive experiments deep
underground. Through the interplay of LHC searches and astrophysics we
are now able to explore new particles as an explanation of the dark matter
of the universe.
Michael Krämer's research group pursues theoretical calculations and analyses
of new physics scenarios which address the hierarchy problem, the origin of
dark matter, or both. They comprise, in particular, precision
calculations for the production and decay of new particles at the LHC, the
exploration of models of dark matter at the LHC and through astrophysical
experiments, and global tests of Higgs properties and new physics models.
In the following interview, Prof. Krämer introduces himself and his research interests: