We study, in a systematic way, the VCKM unitarity relations which arise in extensions of the three generations Standard Model (3gSM) involving the addition of vector-like quarks (VLQ). In particular, we emphasize the effect of the presence of VLQ on VCKM moduli differences, as well on the size of the imaginary parts of rephasing invariant VCKM quartets. We consider the special case where an up-type VLQ is used to attempt at solving the unitarity problem in the first line of VCKM.
@article{arxiv.2307.13073,
title = {Unitarity Relations in the Presence of Vector-Like Quarks},
author = {Francisco Albergaria and Gustavo C. Branco},
journal= {arXiv preprint arXiv:2307.13073},
year = {2023}
}