118633236
Implications of gauge kinetic mixing on Z' and slepton production at the LHC
We consider a supersymmetric version of the standard model extended by an additional U(1)_{B-L}. This model can be embedded in an mSUGRA-inspired model where the mass parameters of the scalars and gauginos unify at the scale of grand unification. In this class of models the renormalization group equation evolution of gauge couplings as well as of the soft SUSY-breaking parameters require the proper treatment of gauge kinetic mixing. We first show that this has a profound impact on the phenomenolgy of the Z' and as a consequence the current LHC bounds on its mass are reduced significantly from about 1920 GeV to 1725 GeV. They are even further reduced if the Z' can decay into supersymmetric particles. Secondly, we show that in this way sleptons can be produced at the LHC in the 14 TeV phase with masses of several hundred GeV. In the case of squark and gluino masses in the multi-TeV range, this might become an important discovery channel for sleptons up to 650 GeV (800 GeV) for an integrated luminosity of 100 fb^{-1} (300 fb^{-1}).
118587432
SO(10) inspired gauge-mediated supersymmetry breaking
We consider a supersymmetric model motivated by a SO(10) grand unified theory: the gauge sector near the supersymmetry scale consists of SU(3)_c x SU(2)_L x U(1)_R x U(1)_{B-L}. We embed this model in minimal gauge mediation and incorporate neutrino data via an inverse seesaw mechanism. Also in this restricted model, the additional D terms can rise the light Higgs mass in a sizable way. Therefore, it is much easier to obtain m_h \simeq 125 GeV without the need to push the supersymmetry spectrum to extremely large values as it happens in models with minimal supersymmetric standard model particle content only. We show that this model predicts a diphoton rate of the Higgs equal to or smaller than the standard model expectation. We discuss briefly the collider phenomenology with a particular focus on the next to lightest supersymmetric particle in which this model offers the sneutrino as an additional possiblity. Moreover, we point out that, also in this model variant, supersymmetry can be discovered in Z' decays even in scenarios in which the strongly interacting particles are too heavy to be produced at a sizable rate at the LHC with 14 TeV. In addition, we show that lepton flavor violating observables constrain the size of the neutrino Yukawa couplings for which, in particular, muon decays and \mu-e conversion in heavy atoms are of particular importance. Once these constraints are fulfilled the rates for \tau decays are predicted to be below the reach of near-future experiments.
120538467
Neutrino mass from higher than d=5 effective operators with discrete symmetries
In beyond Standard Model physics scenarios one often has to extend the Higgs sector and introduce additional (discrete) symmetries. In such models it is possible that the Weinberg operator is forbidden and the leading contribution to neutrino mass is generated by operators with mass dimension d > 5. These higher-dimensional operators are stronger suppressed and therefore the new physics scale can be as low as the TeV scale. With this approach it is possible to test neutrino mass models at colliders, such as the LHC. We will demonstrate how these operators can be systematically studied and present an exemplary implementation of such a model and its phenomenological consequences. We also show how it can be embedded into an SU(5) GUT framework. Finally we present a specific realization of this model where we can have tri-bimaximal mixing with large deviations due to a softly broken symmetry.