PhD Defense – Niels Bohr Institute - University of Copenhagen

Niels Bohr Institute > Events > 2009 > PhD Defense

PhD Defense

Mads Toudal Frandsen (advisor: Francesco Sannino)

Title: Minimal Walking Technicolor Models:
Effective Theories and LHC Phenomenology


 In this thesis we explore the phenomenology and Large Hadron Collider (LHC)
signatures of minimal models of Walking Technicolor featuring
near conformal dynamics and technifermions transforming in higher dimensional
representations of the Technicolor gauge group.

We construct the low energy effective theory of composite states and new
leptons predicted by the models and obtain constraints on the parameters of
the effective theory from electroweak precision data.

We encode the walking behavior of the underlying Technicolor gauge theory
through modified Weinberg sum rules resulting in distinct relations for the
spectrum of vector and axial-vector  mesons. In addition we consider a model
which does not emerge from walking type dynamics but features a custodial
symmetry allowing for degenerate vector and axial-vector mesons.

We analyze the potential of the LHC to observe
the models based on our effective Lagrangian description.
The heavy vectors may be produced and detected via Drell-Yan type processes
while vector boson fusion is less promising. Production of the composite
Higgs in association with a Standard Model gauge boson can provide a distinct
signal of minimal models of Walking Technicolor at LHC. Finally we study
signals of a Technicolor dark matter candidate at LHC as well as parameter
space constraints from dark matter searches.

More generally, the work presented is aimed towards providing a framework in
which relevant theoretical developments in new strong dynamics from ongoing
analytical studies and lattice simulations may be turned into LHC predictions
for minimal models of Walking Technicolor.