9926808
Towards 5D Grand Unification without SUSY Flavor Problem
We consider the renormalization group approach to the SUSY flavor problem in the supersymmetric SU(5) model with one extra dimension. In higher dimensional SUSY gauge theories, it has been recently shown that power corrections due to Kaluza-Klein states of gauge fields run the soft masses generated at the orbifold fixed point to flavor conserving values in the infra-red limit. In models with GUT breaking at the brane where the GUT scale can be larger than the compactification scale, we show that the addition of a bulk Higgs multiplet, which is necessary for the successful unification, is compatible with the flavor universality achieved at the compactification scale.
119116990
Vector Higgs-portal dark matter and Fermi-LAT gamma ray line
We propose a renormalizable model for vector dark matter with extra U(1) gauge symmetry, which is broken by the VEV of a complex singlet scalar. When the singlet scalar has a quartic coupling to a heavy charged scalar, the resonance effect enhances the annihilation cross section of vector dark matter into two photons such that Fermi-gamma ray line at about 130 GeV is obtained. In the presence of a tiny mixing between the singlet scalar and the Standard Model Higgs doublet, the relic density is determined dominantly by WW/ZZ and two-photon channels near the resonance pole of the singlet scalar. We also show that various phenomenological bounds coming from the Higgs to diphoton decay rate, precision data and collider searches for the charged scalar and vacuum stability are satisfied in the model.
42769057
Conditions for large non-Gaussianity in two-field slow-roll inflation
We study the level of primordial non-Gaussianity in slow-roll two-field inflation. Using an analytic formula for the non-linear parameter fNL in the case of a sum or product separable potential, we find that it is possible to generate significant non-Gaussianity even during slow-roll inflation with Gaussian perturbations at Hubble exit. In this paper we give the general conditions for obtaining large non-Gaussianity and calculate the level of fine-tuning required to obtain this. We present explicit models in which the non-Gaussianity at the end of inflation can exceed the current observational bound of .
14862395
Softness of brane-localized supersymmetry breaking on orbifolds
Abstract We consider the brane-localized supersymmetry breaking in 5D compactified on S 1 / Z 2 . In case of a bulk gaugino with arbitrary brane masses for its even and odd modes, we find the mass spectrum and the wave functions of gaugino. We show that the gaugino masses at the distant brane are soft in the usual sense in the effective field theory with zero modes of bulk gauge fields and they are also extremely soft in view of the one-loop finite mass of a brane scalar in the KK regularization.
119366917
Double suppression of FCNCs in supersymmetric models
A mechanism for double suppression of flavor-changing neutral currents (FCNCs) and CP violating phases in supersymmetric models is suggested. At M{sub SUSY} they are suppressed due to a nonabelian discrete flavor symmetry, and the infrared attractive force of gauge interactions in extra dimensions are used to suppress them at the compactification scale. We present a concrete model, which is a simple extension of S{sub 3} invariant minimal supersymmetric standard model, where only SU(2){sub L} and SU(3){sub C} gauge multiplets are assumed to propagate in the bulk. We find that a disorder of 2 orders of magnitude in soft supersymmetry breaking parameters above the compactification scale may be allowed to satisfy experimental constraints on FCNC processes and CP violating phenomena.
7390821
Spectral running and non-Gaussianity from slow-roll inflation in generalized two-field models
Theories beyond the standard model such as string theory motivate low energy effective field theories with several scalar fields which are not only coupled through a potential but also through their kinetic terms. For such theories we derive the general formulae for the running of the spectral indices for the adiabatic, isocurvature and correlation spectra in the case of two-field inflation. We also compute the expected non-Gaussianity in such models for specific forms of the potentials. We find that the coupling has little impact on the level of non-Gaussianity during inflation.
119286463
Peccei-Quinn NMSSM in the light of 125 GeV Higgs
A bstractWe study the phenomenology of the Peccei-Quinn invariant extension of the next-to-minimal supersymmetric standard model (NMSSM) in view of the recent discovery of a 125 GeV Higgs boson. The minimal model having no quadratic and cubic terms of the NMSSM singlet field predicts a light singlino-like lightest supersymmetric particle (LSP). The model is strongly constrained by the Higgs invisible decay and the dark matter characteristic of the LSP, while some constraints can be relaxed by assuming that the saxion, the CP-even companion of the axion in the Peccei-Quinn sector, causes a late-time entropy production diluting the thermal LSP density. The collider signal of the model contains multi-jet and h/W/Z plus missing energy, which can be discovered in the early stage of the 14 TeV LHC running.
125848056
Gauge Unification via Stable Brane Recombination
We study the transition between parallel and intersecting branes on a torus. Spontaneous symmetry breaking of nonabelian gauge symmetry is understood as brane separation, and a more general intermediate deformation is discussed. We argue that there exists supersymmetry preserving transition and we can always have parallel branes as a final state. The transition is interpreted due to dynamics of the F‐ and D‐string junctions and their generalization to (F, Dp) bound states. The gauge group and coupling unification is achieved, also as a result of supersymmetry. From the tadpole cancelation condition, we naturally have some class of intersecting brane models as broken phases of Type I theory with SO(32) gauge group.
119181837
Axial charges of the nucleon and N* resonances
The axial charges of the nucleon and the well-established N * resonances are studied within a consistent framework. For the first time the axial charges of the N * resonances are produced for the relativistic constituent quark model. The axial charge of the nucleon is predicted close to experiment, and the ones of N * (1535) and N * (1650), the only cases where such a comparison is possible, agree well with results from quantum chromodynamics on the lattice that have recently become available. The relevance of the magnitudes of the N * axial charges for the low-energy behavior of quantum chromodynamics is discussed.
119250759
Flavor structure from magnetic fluxes and non-Abelian Wilson lines
We study the flavor structure of four-dimensional (4D) effective theories, which are derived from extra dimensional theories with magnetic fluxes and non-Abelian Wilson lines. We study zero-mode wave functions in generic case and compute Yukawa couplings as well as four-point couplings. In our models, we also discuss non-Abelian discrete flavor symmetries such as ${D}_{4}$, $\ensuremath{\Delta}(27)$, and $\ensuremath{\Delta}(54)$. The orbifold background is also studied.
15407826
Gauged U(1)R symmetries and Fayet-Iliopoulos terms in 5D orbifold supergravity
We discuss a gauged U(1)R supergravity on five-dimensional (5D) orbifold (S1/Z2) in which both a Z2-even U(1) gauge field and the Z2-odd graviphoton take part in the U(1)R gauging. Based on the off-shell formulation of 5D supergravity, we analyze the structure of Fayet-Iliopoulos (FI) terms allowed in such model. Introducing a Z2-even U(1)R gauge field accompanies new bulk and boundary FI terms in addition to the known integrable boundary FI term which could be present in the absence of any gauged U(1)R symmetry. Some physical consequences of these new FI terms are examined.