Dynamical supersymmetry breaking with a large internal dimension

Abstract

Supersymmetry breaking in string perturbation theory predicts the existence of a new dimension at the TeV scale. The simplest realization of the minimal supersymmetric Standard Model in the context of this mechanism has two important consequences: (i) A natural solution to the µ-problem; (ii) The absence of quadratic divergences in the cosmological constant, which leads to a dynamical determination of the supersymmetry breaking and electroweak scale. We present an explicit example in which the whole particle spectrum is given as a function of the top quark mass. A generic prediction of this mechanism is the existence of Kaluza-Klein excitations for gauge bosons and higgses. In particular the first excitation of the photon could be accessible to future accelerators and give a clear signal of the proposed mechanism.

GUT precursors and entwined SUSY: The phenomenology of stable nonsupersymmetric strings

“…The central ingredient in the compactification is the introduction of the Scherk-Schwarz action following the socalled coordinate-dependent compactification (CDC) method of Refs. [43][44][45][46][47][48]. This spontaneously breaks supersymmetry but retains the desirable properties of the original theory, in particular modular invariance, misaligned SUSY, and hence one-loop finiteness.…”

Dark matter with Dirac and Majorana gaugino masses

“…The soft nature of these masses requires a modification of the interaction as was shown using D-term breaking by [2,3]. More recently, Dirac gauginos have arisen in models with an extra dimension where supersymmetry is broken by a Scherk-Schwarz mechanism (see for example [4,5]). More precisely, they are a combination of two Majorana fermions with mass given by 1/2R (half of the compactification scale 1/R), one given by the (mass shifted) massless mode and the other from the (mass shifted) first Kaluza-Klein state, thus, the DG-adjoints originate as "half of the first Kaluza-Klein excitation".…”

The effects of non-universal extra dimensions on the fermion electric dipole moments in the two Higgs doublet model

“…The effects of each extra dimension is felt with the production of Kaluze-Klein (KK) states of the fields, which are obtained after the compactification on a circle of radius R. The number 1/R is known as the compactification scale and the its size have been estimated in the range 200 − 500 GeV , using electroweak precision measurements [18], the B −B -mixing [19], [20] and the flavor changing process b → sγ [21]. Furthermore, this size has been obtained as large as few hundereds of GeV in several works [23,24,25,26,27]. If all the fields live in higher dimensions [18,26], such extra dimensions are called as 'universal extra dimensions' (UED's), and in this case the extra dimensional momentum, and therefore the KK number at each vertex, is conserved.…”