Narrow Results

We consider a supersymmetric hybrid inflation in the framework of the Randall–Sundrum type-2 braneworld model. We derive an analytical expression for the effective scalar potential and find that the D-term dominates hybrid inflation process. We show that we can eliminate partially the fine tuning problem related to coupling constant λ of the potential and calculate the value of FI-term ξ according to recent WMAP7 observation data. We show also that some inflationary spectrum parameters, in particular, the ratio r and the running are widely consistent with WMAP7, BAO and H₀ data.

In order to produce a low-energy effective field theory from a string model, it is necessary to specify a vacuum state. In order that this vacuum be supersymmetric, it is well known that all field expectation values must be along so-called flat directions, leaving the F- and D-terms of the scalar potential to be zero. The situation becomes particularly interesting when one attempts to realize such directions while assigning vacuum expectation values to fields transforming under non-Abelian representations of the gauge group. Since the expectation value is now shared among multiple components of a field, satisfaction of flatness becomes an inherently geometrical problem in the group space. Furthermore, the possibility emerges that a single seemingly dangerous F-term might experience a self-cancellation among its components. The hope exists that the geometric language can provide an intuitive and immediate recognition of when the D and F conditions are simultaneously compatible, as well as a powerful tool for their comprehensive classification. This is the avenue explored in this paper, and applied to the cases of SU(2) and SO(2N), relevant respectively to previous attempts at reproducing the MSSM and the flipped SU(5) GUT. Geometrical interpretation of non-Abelian flat directions finds application to M-theory through the recent conjecture of equivalence between D-term strings and wrapped D-branes of Type II theory.¹ Knowledge of the geometry of the flat direction "landscape" of a D-term string model could yield information about the dual brane model. It is hoped that the techniques encountered will be of benefit in extending the viability of the quasirealistic phenomenologies already developed.

Under a few mild assumptions, supersymmetry (SUSY) in four dimensions is shown to be spontaneously broken in a metastable vacuum in a self-consistent Hartree–Fock approximation of Bardeen–Cooper–Schrieffer/Nambu–Jona-Lasinio (BCS/NJL) type to the leading order, in the gauge theory specified by the gauge kinetic function and the superpotential of adjoint chiral superfields, in particular, that possess extended SUSY spontaneously broken to at tree level. We derive an explicit form of the gap equation, showing the existence of a nontrivial solution. The gauginos in the observable sector receive mixed Majorana–Dirac masses and are split due to both the nonvanishing 〈D⁰〉 and 〈F⁰〉 induced with 〈D⁰〉. It is argued that proper physical applications and assessment of the range of the validity of our framework are made possible by rendering the approximation into expansion.

We consider an supersymmetric U(N) gauge theory with an adjoint chiral multiplet. By developing a self-consistent Hartree-Fock approximation to the leading order which is reminiscent of that of the BCS/NJL in the superconductivity/chiral symmetry, we show that the supersymmetry is spontaneously broken, giving a mixed Majorana-Dirac mass term for gaugino due to the nonvanishing D-term VEV and F-term one induced by D-term.

Matrix elements of the energy momentum tensor (EMT) bear fundamental information like mass, spin and D-term of a particle which is the “last unknown global property.” Recent progress on EMT form factors of hadrons, their interpretations and applications as well as the experimental status is given.

We show that the sizable D-term contributions to the sfermion mass spectrum can be signatures of a certain grand unified theory (GUT), E₆×SU(2)_F×U(1)_A GUT. Note that these D-term contributions destroy the degeneracy of sfermion masses among different generations in this model. Such D-terms are strongly constrained by the FCNC processes if the SUSY breaking scale is the weak scale. However, in E₆×SU(2)_F×U(1)_A, natural SUSY type sfermion mass spectrum is obtained, and if the masses of 10₃ sfermions are larger than O(1) TeV to realize 125 GeV Higgs and the other sfermion masses are O(10) TeV, then sizable D-term contribution is allowed. If the deviations by these D-terms can be observed in future experiments like 100 TeV proton collider or muon collider, we may confirm the E₆×SU(2)_F×U(1)_A GUT.

We present the mechanism of the dynamical supersymmetry (SUSY) breaking at the metastable vacuum in the SUSY gauge theory with adjoint superfields. The dynamical SUSY breaking is triggered by the non-vanishing D-term coupled to the observable sector, and is realized by the self-consistent Hartree-Fock approximation of the NJL type while it eventually brings us the non-vanishing F-term as well. We numerically check the local stability of our metastable vacuum.