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Anthropic tuning of the weak scale and of m_u/m_d in two-Higgs-doublet models

S. M. Barr·Almas Khan
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Abstract

It is shown that in a model in which up-type and down-type fermions acquire mass from different Higgs doublets, the anthropic tuning of the Higgs mass parameters can explain the fact that the observed masses of the $d$ and $u$ quarks are nearly the same with $d$ slightly heavier. If Yukawa couplings are assumed not to "scan" (vary among domains), this would also help explain why the t quark is much heavier than the b quark. It is also pointed out that the existence of dark matter invalidates some earlier anthropic arguments against the viability of domains where the Standard Model Higgs has positive $μ^2$, but makes other even stronger arguments possible.

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S. M. Barr, Almas Khan. 2007-03-20. Anthropic tuning of the weak scale and of m_u/m_d in two-Higgs-doublet models. https://doi.org/10.1103/physrevd.76.045002

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