A few days ago, the LHCb collaboration reported an evidence for Lepton Universality Violation (LUV) in the beauty-quark decays B -> K l⁺ l^- where l represents muon or electron. They measured the ratio of muon to electron to be (more details see their paper)

This ratio is denoted by R_K. The Standard Model (SM) in particle physics predicts 1.00+/-0.01. So this establishes the first evidence for the Lepton Universality Violation.

SM treats all electrons (eletron, muon and tau) equally except for Higgs. Higgs couples to fermions with a strength proportional to fermion mass. So in principle, Higgs might make such an asymmetry.

The left diagram shows the dominant electro-weak contribution in SM while the right one shows a diagram with Higgs involved. The total contribution will be their vectorial sum. Let us have a rough estimation to see whether Higgs explains this LUV or not.

Here A₀ and A₁ represent the amplitude in the left and right diagram, respectively. For R_K=0.846, we find 

Is this number crazy? In SM, we have

where I missed the electromagnetic coupling constant alpha=1/137 in numerator right after the second equal sign, but I don't want to modify it due to reasons you know; m_c, m_mu and m are the mass of charm quark, muon and Higgs; v is the vaccum expectation value; q² is the momentum transfer (1-6 GeV² as in the paper).

So, Higgs canNOT explain to the Lepton Universality Violation observed in B -> K l+ l-.