Constraints on charged Higgs bosons from D(s)+- -> mu+- nu and D(s)+- -> tau+- nu

TL;DR

This paper investigates how measurements of D(s) decays constrain charged Higgs bosons in the Two Higgs Doublet Model, finding that current data slightly disfavor large contributions from H+- and providing competitive bounds on model parameters.

Contribution

It demonstrates that D(s) decay measurements can set competitive and complementary constraints on charged Higgs parameters, especially with future lattice results.

Findings

Current D(s) decay data slightly disfavor large H+- contributions.

Constraints from D(s) decays are competitive with B and K decay constraints.

Future lattice calculations could tighten these bounds.

Abstract

The decays D(s)+- -> mu+- nu and D(s)+- -> tau+- nu have traditionally been used to measure the D(s)+- meson decay constant f_D(s). Recent measurements at CLEO-c and the B factories suggest a branching ratio for both decays somewhat higher than the Standard Model prediction using f_D(s) from unquenched lattice calculations. The charged Higgs boson (H+-) in the Two Higgs Doublet Model (Type II) would also mediate these decays, but any sizeable contribution from H+- can only suppress the branching ratios and consequently is now slightly disfavoured. It is shown that constraints on the parameters tan(beta) and m_H+- from such decays can be competitive with and complementary to analogous constraints derived from the leptonic meson decays B+- -> tau+- nu_tau and K+- -> mu+- nu_mu, especially if lattice calculations eventually prefer f_D(s) < 250 MeV.