Updated constraints on triplet vev in the Georgi Machacek model

Abstract

The Georgi-Machacek model containing singly as well as doubly charged Higgs bosons besides more than one neutral Higgs bosons preserves the custodial symmetry at the tree level. In addition to the doublet vacuum expectation value (vev) $v_1$ this model has one triplet vev $v_2$, which was most strongly bounded from the above as a function of the custodial triplet mass $m_3$ previously by the $b \rightarrow s \gamma$ data. The observed data from the ATLAS and CMS experiments at the LHC for $\sqrt{s} = 13$ TeV for the channels $p p \rightarrow t \bar{t}$, $t \rightarrow H^+ b$, $H^+ \rightarrow c\bar{s}$, $\tau^+ \nu_{\tau}$ for the low mass charged Higgs set new limits on the triplet vev as a function of light charged Higgs boson afterward. Subsequent ATLAS data for the decay $H^{\pm} \rightarrow \tau^{\pm} \nu_{\tau}$ updates the limit on $v_2$ from the above as a function of $m_3$. The present above limits on $v_2$ is now updated to $6.3 - 13.1$ GeV from the previous value of $7.8 - 17.4$ GeV for the light custodial triplet mass $m_3$ ranging from $130$ to $160$ GeV.