# Search for a light charged Higgs boson decaying to a W boson and a CP-odd Higgs boson in final states with e$\mu\mu$ or $\mu\mu\mu$ in proton-proton collisions at $\sqrt{s} =$ 13 TeV

## TL;DR

This paper searches for a light charged Higgs boson decaying into a W boson and a CP-odd Higgs boson in specific final states, setting the first limits on these decay modes using 13 TeV proton-proton collision data.

## Contribution

It introduces the first experimental limits on the decay of a light charged Higgs into a W boson and a CP-odd Higgs in proton-proton collisions at 13 TeV.

## Key findings

- No evidence for the charged Higgs boson was observed.
- Upper limits on the branching fraction range from 1.9×10^{-6} to 8.6×10^{-6}.
- The results set the first constraints on these decay modes.

## Abstract

A search for a light charged Higgs boson (H$^+$) decaying to a W boson and a CP-odd Higgs boson (A) in final states with e$\mu\mu$ or $\mu\mu\mu$ is performed using data from pp collisions at $\sqrt{s}=$ 13 TeV, recorded by the CMS detector at the LHC and corresponding to an integrated luminosity of 35.9 fb$^{-1}$. In this search, it is assumed that the H$^+$ boson is produced in decays of top quarks, and the A boson decays to two oppositely charged muons. The presence of signals for H$^+$ boson masses between 100 and 160 GeV and A boson masses between 15 and 75 GeV is investigated. No evidence for the production of the H$^+$ boson is found. Upper limits at 95% confidence level are obtained on the combined branching fraction for the decay chain t $\to$ bH$^+$ $\to$ bW$^+$A $\to$ bW$^+\mu^+\mu^-$, of 1.9 $\times$ 10$^{-6}$ to 8.6 $\times$ 10$^{-6}$, depending on the masses of the H$^+$ and A bosons. These are the first limits for these decay modes of the H$^+$ and A bosons.