Oleg Lebedev
(Unknown)

7/26/07, 4:30 PM

Theoretical Models (String Theory and Formal Aspects of SUSY)

Parallel Talk

We study the possibility of realizing the neutrino seesaw mechanism in the
$\E8\times \E8$ heterotic string. In particular, we consider its $\Z6$ orbifold
compactifications leading to the supersymmetric standard model gauge group and
matter content. We find that these models possess all the necessary ingredients
for the seesaw mechanism, including the required Dirac Yukawa couplings and...

Dr
Florian Gmeiner
(NIKHEF)

7/26/07, 4:50 PM

Theoretical Models (String Theory and Formal Aspects of SUSY)

Parallel Talk

Recent progress in the statistical analysis of string theory vacua is summarised. In
particular the classification of compactifications in type II orientifolds using
intersecting brane constructions on different orbifold backgrounds is discussed.
Results of this analysis include frequency distributions of gauge groups and chiral
matter. Special attention is payed to models that contain the...

Prof.
Juergen Reuter
(University of Freiburg)

7/26/07, 5:10 PM

Theoretical Models (String Theory and Formal Aspects of SUSY)

Parallel Talk

Matter-Higgs unification in string-inspired supersymmetric Grand Unified Theories
predicts the existence of colored states in the Higgs multiplets and calls for two
extra generations of Higgs-like fields ('unhiggses'). If these states are present
near the TeV scale, gauge-coupling unification points to the existence of two
distinct scales, 10^15 GeV where right-handed neutrinos and a...

Dr
Akin Wingerter
(Ohio State University)

7/26/07, 5:30 PM

Theoretical Models (String Theory and Formal Aspects of SUSY)

Parallel Talk

In this letter we consider the consequences for the LHC of light
vector-like exotica with fractional electric charge. It is shown
that such states are found in orbifold constructions of the
heterotic string. Moreover, these exotica are consistent with
gauge coupling unification at one loop, even though they do not
come in complete multiplets of SU(5).
(Talk based on arXiv:0705.0294 [hep-ph])

Dr
Christoph Lüdeling
(ITP, Uni Heidelberg)

7/26/07, 5:50 PM

Theoretical Models (String Theory and Formal Aspects of SUSY)

Parallel Talk

We present an orbifold compactification of the heterotic string which leads to a
six-dimensional supergravity theory with the MSSM as the low-energy limit. Bulk and
localised anomalies are cancelled by the Green-Schwarz mechanism. The model contains
two pairs of inequivalent fixed points with gauge symmetries SU(5) and SU(2)xSU(4).
The SU(5) fixed points contain one standard model...

Dr
Bumseok Kyae
(Korea Institute for Advanced Study (KIAS))

7/26/07, 6:10 PM

Theoretical Models (String Theory and Formal Aspects of SUSY)

Parallel Talk

We construct a supersymmetric standard model in the context of
the Z_{12-I} orbifold compactification of the E_8 x E_8' heterotic string theory.
The gauge group is SU(3)_c x SU(2)_L x U(1)_Y x U(1)^4
x [SO(10) x U(1)^3]' with sin^2\theta_W^0 = 3/8.
We obtain three families of SO(10) spinor-like chiral matter states,
and Higgs doublets.
All exotic states are exactly vector-like...