Superpotential de-sequestering in string models
Abstract
Non-perturbative superpotential cross-couplings between visible sector matter and K\"ahler moduli can lead to significant flavour-changing neutral currents in compactifications of type IIB string theory. Here, we compute corrections to Yukawa couplings in orbifold models with chiral matter localised on D3-branes and non-perturbative effects on distant D7-branes. By evaluating a threshold correction to the D7-brane gauge coupling, we determine conditions under which the non-perturbative corrections to the Yukawa couplings appear. The flavour structure of the induced Yukawa coupling generically fails to be aligned with the tree-flavour structure. We check our results by also evaluating a correlation function of two D7-brane gauginos and a D3-brane Yukawa coupling. Finally, by calculating a string amplitude between n hidden scalars and visible matter we show how non-vanishing vacuum expectation values of distant D7-brane scalars, if present, may correct visible Yukawa couplings with a flavour structure that differs from the tree-level flavour structure.
Cite
@article{arxiv.1207.1103,
title = {Superpotential de-sequestering in string models},
author = {Marcus Berg and Joseph P. Conlon and David Marsh and Lukas T. Witkowski},
journal= {arXiv preprint arXiv:1207.1103},
year = {2013}
}
Comments
37 pages + appendices, 8 figures