Scale, Gauge Couplings, Soft Terms and Toy Compactification in M-theory on $S^1/Z_2$

Abstract

In M-theory on $S^1/Z_2$, we point out that to be consistant, we should keep the scale, gauge couplings and soft terms at next order, and obtain the soft term relations: $M_{1/2} = -A$, $|{{M_{0}}/{M_{1/2}}}| \leq {1/{\sqrt 3}}$ in the standard embedding and $M_{1/2}=-A$ in the non-standard embedding with five branes and $K_{5,n}=0$. We construct a toy compactification model which includes higher order terms in 4-dimensional Lagrangian in standard embedding, and discuss its scale, gauge couplings, soft terms, and show that the higher order terms do affect the scale, gauge couplings and especially the soft terms if the next order correction was not small. We also construct a toy compactification model in non-standard embedding with five branes and discuss its phenomenology. We argue that one might not push the physical Calabi-Yau manifold's volume to zero at any point along the eleventh dimension.