Improving bounds on flavor changing vertices in the two Higgs doublet model from B-B mixing

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We find some constraints on the flavor changing vertices of the two Higgs doublet model, from the ΔMBd measurement. Although bounds from this observable have already been considered, this paper takes into account the role of a new operator not included previously, as well as the vertices ξbb, ξtc and ξsb. Using the Cheng-Sher parametrization, we found that for a relatively light charged Higgs boson (200-300 GeV), we get that λtt<1, while the parameter λbb could have values up to about 50. In addition, we use bounds for λtt and λbb obtained from B⁰->Xₛγat next to leading order, and studied the case where the only vanishing vertex factors are the ones involving quarks from the first family. We obtained that ΔMBd is not sensitive to the change of the parameter λsb, while λtc<1