Download like in Arts - Physik und Astronomie an der Universiteat Innsbruck

H. Eberl
RECFA meeting, Innsbruck 2004
Members
Walter Majerotto
Helmut Eberl
Wolfgang Lucha
Sabine Kraml
Christian Weber – fixed term pos.
Karol Kovařík – PhD student
Wilhelm Öller – PhD student
H. Eberl
RECFA meeting. Innsbruck 2004
Working Fields
Supersymmetry (SUSY)
H. Eberl, K. Kovařík, S. Kraml,
W. Majerotto, W. Öller, C. Weber
Bound quark states,
Finite quantum field theories
W. Lucha
H. Eberl
RECFA meeting. Innsbruck 2004
Supersymmetry
The way to the Theory of Everything?
Symmetries play a central rôle in modern physics (like in Arts),
as they reflect the fundamental laws of Nature.
SUPERSYMMETRY – or SUSY for short - is a symmetry
between matter particles (fermions) and carriers of force
(bosons). It offers the possibility of embedding the Standard
Model of particles into a larger and a more complete theory.
a
H. Eberl
RECFA meeting. Innsbruck 2004
Principle of Symmetry:
Symmetry transformations
do not change the form of the
laws of Nature as illustrated
here in this four pictures
all representing our beloved
Marylin despite the colour
and mirror transformations
H. Eberl
RECFA meeting. Innsbruck 2004
SUSY The true love of
particle physists?
Bosonen
Fermionen
In a supersymmetric theory,
for every particle there exist
a partner particle.
If SUSY is realized in Nature
then for every known SM
particle there must be a
supersymmetric partner.
SUSY particle spectrum.
green: known particles of the Standard Model.
red: new particles (Higgs bosons and SUSY partners).
H. Eberl
RECFA meeting. Innsbruck 2004
SUSY-particles in experiments
SUSY particles can have very
spectacular signatures due to
cascade decays.
Here we see a possible squarkgluino production at LHC and the
additional cascade decays of
them.
In the right figure we see a simulation
of such a signature in the CMS
detector.
The search for these new supersymmetric particles is one of the main
tasks of the experiments at the Tevatron in the USA, at LHC at CERN,
and at a Future Linear Collider.
H. Eberl
RECFA meeting. Innsbruck 2004
Main Topics
of the SUSY Group
Renormalization
CP violation in SUSY
radiative
Loop
calculations
corrections
a possible source
Lepton flavour violation
H. Eberl
RECFA meeting. Innsbruck 2004
Renormalization in the MSSM
Goal: Access to higher fundamental “GUT” scale
Precision experiments – Born approximation is not sufficient.
Inclusion of “loop” contributions necessary!
Our contribution: compared to the SM, in the MSSM there are mass matrices
(for sfermions, charginos and neutralinos) and related mixing matrices which have
to be renormalized. We worked out a consistent concept of renormalization
and applied it to many production and decay processes:
SUSY-QCD: gluon and gluino one-loop contributions, e.g.
Higgs decays into fermions and sfermions
Sfermion decays into chargino, neutralino, W, Z, and Higgs bosons
(also crossed channels studied)
3rd gen, sfermion production at a LC
Problem with convergence: Resummation necessary – Improvement worked out
H. Eberl
RECFA meeting. Innsbruck 2004
Yukawa type corrections:
calculated examples are
Sfermion pair prod. at a LC
Single Higgs boson prod. at a LC
Full one-loop corrections:
very complex calculations, done by hand and checked by automatic tools:
A0 decay to sfermion pair
other Higgs decay channels to sfermions in progress
Higgs decays to charginos and neutralinos (still in progress)
Sfermion, chargino and neutralino pair productions in e+e- annihilations
H. Eberl
RECFA meeting. Innsbruck 2004
CP Violation:
The SM cannot explain sufficiently CP viol. which is a necessary ingredient for
the particle-antiparticle asymmetry built by baryogenesis (or leptogenesis).
Many complex parameters in general SUSY – sources for CP violation
Lepton Flavour Violation:
CP sensitive observables proposed by our group (Triple products, …)
applied to e.g.
H+ to t b, t nt
e+e- to tops, charginos, and neutralinos, and additonal decays
Lepton Flavour Violation:
Mass matrices of charged leptons allow large LFV despite the strong
bounds of rare decays like m- to e- g
A possible signatur: e+e- to e+ m-
Also combined studies on CP and LFV
H. Eberl
RECFA meeting. Innsbruck 2004
Contributions to workshops:
We are a small group. Despite this fact
participated in workshops on
LEP, LHC, LC, CLIC and muon collider
W. M. – convenor activity
EU project:
member of the running EU network RMT on collider physics
New project has been submitted this year
H. Eberl
RECFA meeting. Innsbruck 2004
International collaborations
Y. Yamada, K. Hidaka - Japan
T. Gajdosik – Vilnius, Lithuania
D. Denegri - CMS - CERN
W. Porod - Zürich
H. Fraas, O. Kittel - Würzburg
G. Moortgat-Pick - Durham
J. Valle - Valencia
U. Martyn, L. Rurua – DESY Hamburg
M. Beccaria - Lecce
C. Verzegnassi - Trieste
F. Renard - Montpellier
V. Spanos - Minneapolis
EU Marie-Curie fellowship at Hephy Vienna 2001-2003
H. Eberl
RECFA meeting. Innsbruck 2004
Publications 1999-2004
we get from the web
H. Eberl
RECFA meeting. Innsbruck 2004