Investigation of Charged Higgs Bosons Production from Vector-Like $T$ Quark Decays at $e\gamma$ Collider

TL;DR

This study explores the production of charged Higgs bosons from vector-like T quark decays at future high-energy eγ colliders within an extended 2HDM-II framework, highlighting the impact of beam polarization and collider energy on detection prospects.

Contribution

It provides the first detailed analysis of charged Higgs production via VLQ decays at eγ colliders, including polarization effects, optimized event selection, and sensitivity estimates at 2 and 3 TeV energies.

Findings

Polarized beams significantly enhance detection rates.

Higher collider energy improves exclusion and discovery regions.

Systematic uncertainties affect sensitivity estimates.

Abstract

Within the extended framework of the Two-Higgs-Doublet Model Type II (2HDM-II), enhanced by a vector-like quark (VLQ) doublet $TB$, we present a comprehensive analysis of the process $e^{-}\gamma \rightarrow b\nu_{e}\bar{T}$ at future high-energy $e\gamma$ colliders, focusing on the decays $\bar{T} \rightarrow H^{-} \bar{b}$ and $H^{-} \rightarrow \bar{t}b$. Using current theoretical and experimental constraints, we calculate production cross sections for both unpolarized and polarized beams at center-of-mass energies of $\sqrt{s} = 2$ and 3 TeV, demonstrating that polarized beams significantly enhance detection prospects by increasing production rates. By analyzing kinematic distributions, we establish optimized selection criteria to effectively separate signal events from background. At $\sqrt{s} = 2$ TeV with an integrated luminosity of 1500 fb$^{-1}$, we find exclusion regions within $s_R^d\in[0.085,0.16]$ for $m_T\in [1000,1260]$ GeV and a discovery potential within $s_R^d\in[0.14,0.17]$ for $m_T\in[1000,1100]$ GeV, with these regions expanding to $s_R^d\in [0.05,0.15]$ for $m_T\in[1000,1340]$ GeV and $s_R^d \in [0.11, 0.17]$ for $m_T\in[1000,1160]$ GeV at 3000 fb$^{-1}$. At $\sqrt{s} = 3$ TeV and 1500 fb$^{-1}$, we identify exclusion regions of $s_R^d\in[0.055,0.135]$ for $m_T \in [1000, 1640]$ GeV and discovery regions of $s_R^d \in [0.09, 0.15]$ for $m_T \in [1000, 1400]$ GeV, which further expand to $s_R^d \in [0.028, 0.12]$ for $m_T\in[1000,1970]$ GeV and $s_R^d \in[0.04,0.122]$ for $m_T\in[1000,1760]$ GeV at 3000 fb$^{-1}$. Our findings emphasize the increased detection potential at higher center-of-mass energies, particularly at 3 TeV compared to 2 TeV, with notable improvements when polarized beams are utilized. We also account for the effects of initial state radiation, beamstrahlung, and systematic uncertainties, which influence both exclusion and discovery prospects.