Four-dimensional effective supergravity and soft terms inMtheory

Abstract

We provide a simple macroscopic analysis of the four-dimensional effective supergravity of the Hořava-Witten M -theory which is expanded in powers of κ 2/3 /ρV 1/3 and κ 2/3 ρ/V 2/3 where κ 2 , V and ρ denote the eleven-dimensional gravitational coupling, the Calabi-Yau volume and the eleventh length respectively. Possible higher order terms in the Kähler potential are identified and matched with the heterotic string corrections. In the context of this Mtheory expansion, we analyze the soft supersymmetry-breaking terms under the assumption that supersymmetry is spontaneously broken by the auxiliary components of the bulk moduli superfields. It is examined how the pattern of soft terms changes when one moves from the weakly coupled heterotic string limit to the M -theory limit.

Five-branes and supersymmetry breaking in M-Theory

“…[15]. Also, the trilinear soft terms are of that order while the scalar soft masses still vanish [21,22]. As an alternative possibility, consider supersymmetry breaking in the directions F n of the five-brane moduli.…”

“…Both aspects might influence the magnitude of the soft terms compared to perturbative heterotic string, as we will discuss later on in more detail. For standard-embedding vacua of heterotic M-theory and a simple model with one family, soft terms in the presence of corrections have been already studied [15,21,22]. …”

Supersymmetry Breaking in M-theory

“…We generalize the earlier results [13,14,23,24,25] by considering nonstandard embeddings in which charged matter is present on both walls, i.e., in both gauge sectors, and we allow for condensates to form on both walls 4 . Restoring powers of the reduced Planck mass M , the physical gravitino mass in the case of a vanishing cosmological constant in four dimensions is:…”

Relating incomplete data and incomplete theory

“…Using the soft terms expressions as given in [30], we have chosen a point in parameter space where both the dilaton and the overall compactification modulus play equal roles in supersymmetry breaking. The fundamental scale is taken to be Λ uv = Λ gut with g 2 str = 1/2, but with the size of the strong coupling correction such that this occurs for Re S = 1.25 instead of the usual weakly coupled case of Re S = 2.…”