119238697
Natural realization of a large extra dimension in 5D supersymmetric theory
An exponentially large extra dimension can be naturally realized by the Casimir energy and the gaugino condensation in 5D supersymmetric theory. The model does not require any hierarchies among the 5D parameters. The key ingredient is an additional modulus other than the radion, which generically exists in 5D supergravity. SUSY is broken at the vacuum, which can be regarded as the Scherk-Schwarz SUSY breaking. We also analyze the mass spectrum and discuss some phenomenological aspects.
119158878
Inflation in supergravity without Kähler potential
We propose a new class of inflation models in supergravity with higher derivative terms. In those models, the K\"ahler potential does not contain the inflaton multiplet, but a supersymmetric derivative term does. In the models, inflation is effectively driven by a single scalar field with a standard kinetic term and a scalar potential. Remarkably, the so-called $\eta$ problem does not exist in our models.
119260215
Instant uplifted inflation: a solution for a tension between inflation and SUSY breaking scale
A bstractThe Hubble parameter during an inflationary era must be smaller than the gravitino mass if moduli fields are stabilized by the Kachru-Kallosh-Linde-Trivedi mechanism. This condition represents a difficulty to combine low scale SUSY breaking and high scale inflation. We propose a simple mechanism which can naturally separate the inflation scale from the SUSY breaking scale today.
44450900
Illustrating SUSY breaking effects on various inflation mechanisms
A bstractWe consider the supersymmetry breaking effects on typical inflation models with different types of Kähler potential. The critical size of supersymmetry-breaking scale, above which the flatness of the inflaton potential is spoiled, drastically changes model by model. We present the universal description of such effects in terms of a field-dependent scaling factor by which gravity-mediated supersymmetry breaking terms are suppressed or enhanced, based on the conformal supergravity framework. Such a description would be useful when we estimate them in constructing supersymmetric models of particle cosmology.
119288533
Reheating processes after Starobinsky inflation in old-minimal supergravity
A bstractWe study reheating processes and its cosmological consequences in the Starobinsky model embedded in the old-minimal supergravity. First, we consider minimal coupling between the gravity and matter sectors in the higher curvature theory, and transform it to the equivalent standard supergravity coupled to additional matter superfields. We then discuss characteristic decay modes of the inflaton and the reheating temperature TR. Considering a simple model of supersymmetry breaking sector, we estimate gravitino abundance from inflaton decay, and obtain limits on the masses of gravitino and supersymmetry breaking field. We find TR ≃ 1.0 × 109 GeV and the allowed range of gravitino mass as 104 GeV ≲ m3/2 ≲ 105 GeV, assuming anomaly-induced decay into the gauge sector as the dominant decay channel.
119278125
SUSY flavor structure of generic 5D supergravity models
We perform a comprehensive and systematic analysis of the SUSY flavor structure of generic 5D supergravity models on S1/Z2 with multiple Z2-odd vector multiplets that generate multiple moduli. The SUSY flavor problem can be avoided due to contact terms in the 4D effective Kähler potential peculiar to the multi-moduli case. A detailed phenomenological analysis is provided based on an illustrative model.
17419321
Two-loop renormalization of gaugino mass in supersymmetric gauge model
Abstract We study the two-loop renormalization group equation for the running gaugino mass in the supersymmetric gauge theory. We find that both in the MS and DR renormalization schemes, the well-known proportionality of the runnings of the gaugino mass and the gauge coupling constant is violated at the two-loop order, even in models with vector supermultiplets only. The scheme dependence of the running gaugino mass is clarified.
18745983
Light Higgsino Dark Matter
We re–investigate the question whether a light higgsino–like neutralino is a viable Dark Matter candidate. To this end we compute the dominant one–loop corrections to the masses of the higgsino–like states in the minimal Supersymmetric Standard Model (MSSM), due to loops involving heavy quarks and their superpartners. We also calculate analogous corrections to the couplings of higgsino–like neutralinos to Z and Higgs bosons. In the region of parameter space leading to high higgsino purity of the lightest neutralino, these corrections can change the expected relic density by up to a factor of five in either direction. We conclude that for favorable choices of soft supersymmetry breaking parameters, a state with more than 99% higgsino purity could indeed form all cold Dark Matter in the Universe. In some cases these corrections can also increase the expected cross section for LSP scattering off spinless nuclei by up to two orders of magnitude, or reduce it to zero.
16568046
Higgs Particle Decays in Supersymmetry
We present a detailed study of the decays of the Higgs bosons H+, H0, and A0 within the Minimal Supersymmetric Standard Model including SUSY–QCD corrections. We find that the supersymmetric modes tb (tt, and for large tan β bb) can dominate the H+ (H0, A0) decays in a wide range of the model parameters due to the large Yukawa couplings and mixings of t and b. Compared to the conventional modes H+→τ+ντ, tb, and H0, A0→tt,bb, the supersymmetric modes can have an important impact on the Higgs boson searches at future colliders.
17333378
SUSY - QCD corrections to top and bottom squark decays into Higgs bosons
We calculate the $\mathcal{O}({\ensuremath{\alpha}}_{s})$ SUSY-QCD corrections to the widths of top and bottom squark decays into Higgs bosons within the minimal supersymmetric standard model. We give the complete analytical formulas, paying particular attention to the on-shell renormalization of the soft SUSY-breaking parameters. We also perform a detailed numerical analysis of both top and bottom squark decays into all Higgs bosons ${h}^{0},$ ${H}^{0},$ ${A}^{0},$ and ${H}^{\ifmmode\pm\else\textpm\fi{}}.$ We find that the SUSY-QCD corrections are significant, mostly negative, and of the order of a few ten percent.
2763498
One-loop corrections to the chargino and neutralino mass matrices in the on-shell scheme
We present a consistent procedure for the calculation of the one-loop corrections to the charginos and neutralinos by using their on-shell mass matrices. The on-shell gaugino mass parameters M and M', and the Higgsino mass parameter \mu are defined by the elements of these on-shell mass matrices. The on-shell mass matrices are different by finite one-loop corrections from the tree-level ones given in terms of the on-shell parameters. When the on-shell M and \mu are determined by the chargino sector, the neutralino masses receive corrections up to 4%. This must be taken into account in precision measurements at future e^+ e^- linear colliders.