Herrero-Garcia, J.Nebot, M.Rajec, F.White, M.Williams, A.G.2020-05-082020-05-082020The Journal of High Energy Physics, 2020; 2020(2):1-381126-67081029-8479http://hdl.handle.net/2440/124635Published: February 25, 2020We study quark flavor violating interactions mediated by the Higgs boson h. We consider observables involving a third generation quark, of both the up and the down quark sectors, like h → bs and t → ch. Using an effective field theory approach we systematically list all the possible tree-level ultraviolet completions, which comprise models with vector-like quarks and/or extra scalars. We provide upper bounds on the flavor violating transitions allowed by current limits stemming from low energy processes, such as meson mixing and b → sγ. We find that scenarios with vector-like quarks always have very suppressed flavor-violating transitions, while a general Two-Higgs-Doublet Model may have a sizeable rate. To study the latter case in detail, we perform a full numerical simulation taking into account all relevant theoretical and phenomenological constraints. Our results show that BR(t → ch) [BR(h → bs)] are still allowed at the sub-percent [percent] level, which are being [may be] explored at the LHC [future colliders]. Finally, we have found that the mild mass-splitting discrepancy with respect to the SM in the Bs meson system can be accommodated in the Two-Higgs-Doublet Model. If confirmed, it yields the prediction BR(h → bs) ≃ 10⁻⁴, if the new contribution to the mass-splitting is dominated by tree-level Higgs boson exchange.enOpen Access, © The Authors. Article funded by SCOAP3. Open Access. This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.Phenomenological ModelsJournal article100001621410.1007/JHEP02(2020)1470005185797000012-s2.0-85080079054481150Herrero-Garcia, J. [0000-0002-3300-0029]White, M. [0000-0001-5474-4580]Williams, A.G. [0000-0002-1472-1592]