LHC $\tau$-rich Tests of Lepton-specific 2HDM for $(g-2{)}_{\mu }$

Abstract

The lepton-sepcific (or type X) 2HDM (L2HDM) is an attractive new physics candidate explaining the muon $g-2$ anomaly requiring a light CP-odd boson $A$ and large $\tan \beta$. This scenario leads to $\tau$-rich signatures, such as $3\tau$, $4\tau$ and $4\tau +W/Z$, which can be readily accessible at the LHC. We first study the whole L2HDM parameter space to identify allowed regions of extra Higgs boson masses as well as two couplings ${\lambda }_{hAA}$ and ${\xi }_h^l$ which determine the 125 GeV Higgs boson decays $h\to {\tau }^{+}{\tau }^{-}$ and $h\to AA/A{A}^{\ast }({\tau }^{+}{\tau }^{-})$, respectively. This motivates us to set up two regions of interest: (A) $m_A\ll m_H\sim m_{H^{\pm }}$, and (B) $m_A\sim m_{H^{\pm }}\sim \mathcal{O}(100)\text{mbox}GeV\ll m_H$, for which derive the current constraints by adopting the chargino-neutralino search at the LHC8, and then analyze the LHC14 prospects by implementing $\tau$-tagging algorithm. A correlated study of the upcoming precision determination of the 125 GeV Higgs boson decay properties as well as the observation of multi-tau events at the next runs of LHC will be able to shed light on the L2HDM option for the muon $g-2$.

Comments: 21 pages, 9 figures