SUSY07

Session

Theoretical Models (String Theory and Formal Aspects of SUSY) 2

Models2

26 Jul 2007, 16:30

Physics Building (Karlsruhe University)

66. See-saw neutrinos from string theory

Oleg Lebedev (Unknown)

26/07/2007, 16:30

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...

101. Exploring the landscape - statistics of string theory vacua

Dr Florian Gmeiner (NIKHEF)

26/07/2007, 16:50

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...

153. SUSY Multi-Step Unification without Doublet-Triplet Splitting

Prof. Juergen Reuter (University of Freiburg)

26/07/2007, 17:10

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...

218. Gauge coupling unification and Light Exotica in String Theory

Dr Akin Wingerter (Ohio State University)

26/07/2007, 17:30

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])

253. Local SU(5) Unification in 6D from the Heterotic String

Dr Christoph Lüdeling (ITP, Uni Heidelberg)

26/07/2007, 17:50

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...

274. GUT-like Superstring Standard Model from the Heterotic String

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

26/07/2007, 18:10

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...