Wave-function profile and SUSY breaking in 5D model with Fayet-Iliopoulos terms

TL;DR

This paper investigates how Fayet-Iliopoulos terms influence the vacuum expectation values and profiles of fields in a 5D orbifold model, affecting SUSY breaking and scalar mass hierarchies.

Contribution

It provides a systematic analysis of field profiles and SUSY breaking effects in a 5D model with FI terms, including a toy model for SUSY breaking and its impact on scalar masses.

Findings

Gaussian profiles of zero modes in SUSY-breaking case

Bulk D-term contributions to scalar masses are significant

Profiles and mass eigenvalues of higher modes are characterized

Abstract

We systematically study VEVs of a gauge scalar field $\Sigma$ in a bulk U(1) vector multiplet and scalar fields in brane/bulk hypermultiplets charged under U(1) in the 5D $S^1/Z_2$ orbifold model with generic FI terms. A non-trivial VEV of $\Sigma$ generates bulk mass terms for U(1) charged fields, and their zero modes have non-trivial profiles. In particular, in the SUSY-breaking case, bosonic and fermionic zero modes have Gaussian profiles. Such non-trivial profiles are useful to explain hierarchical couplings. A toy model for SUSY breaking is studied, and it yields sizable $D$-term contributions to scalar masses. Because the overall magnitude of $D$-term contributions is the same everywhere in the bulk and also on both branes, we have to take into account these contributions and other SUSY-breaking terms to obtain a realistic description. We also give profiles and mass eigenvalues of higher modes.