Approaching robust EFT limits for CP-violation in the Higgs sector
Abstract
Constraining CP-violating interactions in effective field theory (EFT) of dimension six faces two challenges. Firstly, degeneracies in the multi-dimensional space of Wilson coefficients have to be lifted. Secondly, quadratic contributions of CP-odd dimension six operators are difficult to disentangle from squared contributions of CP-even dimension six operators and from linear contributions of dimension eight operators. Both of these problems are present when new sources of CP-violation are present in the interactions between the Higgs boson and heavy strongly-interacting fermions. We show that degeneracies in the Wilson coefficients can be removed by combining measurements of Higgs-plus-two-jet production via gluon fusion with measurements of top-pair associated Higgs production. In addition, we demonstrate that the sensitivity of the analysis can be improved by exploiting the top-quark threshold in the gluon fusion process. Finally, we substantiate a perturbative argument about the validity of EFT by comparing the quadratic and linear contributions from CP-odd dimension six operators and use this to show explicitly that high statistics measurements at future colliders enable the extraction of perturbatively robust constraints on the associated Wilson coefficients.
Cite
@article{arxiv.1901.05982,
title = {Approaching robust EFT limits for CP-violation in the Higgs sector},
author = {Christoph Englert and Peter Galler and Andrew Pilkington and Michael Spannowsky},
journal= {arXiv preprint arXiv:1901.05982},
year = {2019}
}
Comments
13 pages, 10 figures, 2 tables, v2: published version