Flavor structure with multi-moduli in 5D supergravity

Abstract

We study five-dimensional supergravity on ${S}^{1}/{Z}_{2}$ with a physical ${Z}_{2}$-odd vector multiplet, which yields an additional modulus other than the radion. We derive four-dimensional effective theory and find additional terms in the K\"ahler potential that are peculiar to the multi-moduli case. Such terms can avoid tachyonic soft scalar masses at tree level, which are problematic in the single modulus case. We also show that the flavor structure of the soft terms are different from that in the single modulus case when hierarchical Yukawa couplings are generated by wave function localization in the fifth dimension. We present a concrete model that stabilizes the moduli at a supersymmetry breaking Minkowski minimum and show the low-energy sparticle spectrum.