Discrimination of Supersymmetric Grand Unified Models in Gaugino Mediation

We consider supersymmetric grand unified theory (GUT) with the gaugino mediated supersymmetry breaking and investigate a possibility to discriminate different GUT models in terms of predicted sparticle mass spectra. Taking two example GUT models, the minimal SU(5) and simple SO(10) models, and imposing a variety of theoretical and experimental constraints, we calculate sparticle masses. Fixing parameters of each model so as to result in the same mass of neutralino as the lightest supersymmetric particle (LSP), giving the observed dark matter relic density, we find sizable mass differences in the left-handed slepton and right-handed down-type squark sectors in two models, which can be a probe to discriminate the GUT models realized at the GUT scale far beyond the reach of collider experiments.Comment: 14 pages, 4 figures, version to be published in PR

Positively deflected anomaly mediation in the light of the Higgs boson discovery

Anomaly-mediated supersymmetry breaking (AMSB) is a well-known mechanism for flavor-blind transmission of supersymmetry breaking from the hidden sector to the visible sector. However, the pure AMSB scenario suffers from a serious drawback, namely, the tachyonic slepton problem, and needs to be extended. The so-called (positively) deflected AMSB is a simple extension to solve the problem and also provides us with the usual neutralino lightest superpartner as a good candidate for dark matter in the Universe. Motivated by the recent discovery of the Higgs boson at the Large Hadron Collider (LHC) experiments, we perform the parameter scan in the deflected AMSB scenario by taking into account a variety of phenomenological constraints such as the dark matter relic density and the observed Higgs boson mass around 125-126 GeV. We identify the allowed parameter region and list benchmark mass spectra. We find that in most of the allowed parameter regions, the dark matter neutralino is Higgsino-like and its elastic scattering cross section with nuclei is within the future reach of the direct dark matter search experiments, while (colored) sparticles are quite heavy and their discovery at the LHC is challenging.Comment: 16 pages, 5 figures, Version to be published in PR

Discrimination of SUSY breaking models using single-photon processes at future e+e- linear colliders

We examine the single-photon processes in the frame work of supersymmetric models at future e+e- linear colliders. According to the recent experimental achievement, the optimistic polarization degrees for both electron and positron beams are taken into account to enhance the signal-to-noise ratio revealing the observable difference between supersymmetry breaking models. The minimal supergravity model and the minimal SU(5) grand unified model in gaugino mediation have been examined as examples. We see that after several years of accummulating data, the difference of the number of single-photon events between the two models received from the collider would be in excess of three times the statistical error, providing us the possibility to probe which model would be realized in nature. The result is well suitable for the future running of the International Linear Collider.Comment: 14 pages, 4 figures, version to be published in Mod. Phys. Lett.

Tau g−2g-2 at e−e+e^-e^+ colliders with momentum dependent form factor

The deviation between the standard model prediction and the measurement of the muon g-2 is currently at 3-4 sigma (can be up to 7 sigma in the upcoming experiment E989). If new physics is responsible for such discrepancy, it is expected that the new contributions to tau g-2 are even larger than that for muon due to its large mass. In spite of that, the tau g-2 is much more difficult to be directly measured because of its short lifetime. In this paper, we consider the effect of the tau g-2 at $e^-e^+$ colliders in a model independent way. Using the tau pair production channel at the Large Electron Position Collider (LEP), we have found the allowed range for the new physics contribution of the tau g-2 assuming a $q^2$-dependence ansatz for the magnetic form factor. In our analysis, we take into account the standard model one-loop correction as well as the initial state photon radiation. We have also investigated the prospect at future $e^-e^+$ colliders, and determine the expected allowed range for the new physics contribution to the tau g-2. Given the proposed beam polarization configuration at the International Linear Collider (ILC), we have analyzed the dependence of this allowed range on the integrated luminosity as well as the relative systematic error.Comment: 18 pages, 6 figure

Grundlegende betrachtungen zur wirkung eines "inversen" spanungsverhältnisses als basis für die fräswerk-zeugkonstruktion

The demand for higher productivity and quality, flexibility as well as process safety are marking the development in the field of metal-cutting manufacturing process. Thereby the field of low vibration milling plays a special role. Therefore the development and design of modern milling tools is more and more often affected by novel machining strategies. The article deals with the development and design of a low vibration milling tool including the reversal of conventional chip- cross- section b/h > 1 to the "invers" ratio b/h < 1. For this the difference between the two cross sections will be analysed. The focus of the first experimental research is the determination of the effects of reversing the chip- cross- section on the cutting forces as well as chip formation and - forming. The influence of the tool side rake angle (γf) in milling with "inverse" chip- cross- section will be studied. The results gathered in the field of "inverse" chip- cross- ratio provides the base for formulation of design fundamentals and drafts of a novel milling tool with peeling function

Kinetic mixing in models with an extra Abelian gauge symmetry

The Lagrangian of a theory possessing two Abelian gauge symmetries may contains a gauge kinetic mixing term without violating any known symmetries. In this paper, the formulation of theories extended by an additional Abelian gauge symmetry in the superfield formalism is presented. By rotating in the space of the gauge fields, the gauge kinetic mixing term can be eliminated, and the relevant charge and coupling are shifted in comparison with the original quantities. This process is valid for both theories with or without supersymmetry. We demonstrate, for example, the effect of the gauge kinetic mixing term in  the case of the U(1) extension of the minimal supersymmetric standard model. Various physical observables are computed for a given benchmark point. We find that the gauge kinetic mixing is important for the model to predict the observables in a good agreement with experimental data