Probing triple higgs self coupling and effect of beam polarization in lepton colliders

TL;DR

This paper investigates the measurement of Higgs self-coupling at future lepton colliders within the two Higgs doublet model, analyzing the impact of beam polarization and different energy scenarios on production cross-sections and event rates.

Contribution

It provides a numerical analysis of Higgs self-coupling extraction in 2HDM, considering beam polarization effects and specific model parameters at energies up to 3 TeV.

Findings

Beam polarization enhances Higgs production cross-sections.

Event rate estimates for different luminosities and energies.

Analysis within the exact alignment limit of 2HDM.

Abstract

One of the main objectives of almost all future (lepton) colliders is to measure the self-coupling of triple Higgs in the Standard Model. By elongating the Standard Model's scalar sector, using incipient Higgs doublet along with a quadratic (Higgs) potential should reveal many incipient features of the model and the possibility of the emergence of additional Higgs self-couplings. The self-coupling of the Higgs boson helps in reconstructing the scalar potential. The main objective of this paper is to extract Higgs self-coupling by numerically analyzing several scattering processes governed by two Higgs doublet models (2HDM). These scattering processes include various possible combinations of final states in the triple Higgs sector. The determination of production cross-section of scattering processes is carried out using two different scenarios, with and without polarization of incoming beam and is extended to a center of mass energy up to $\sqrt{s}$ = 3 $TeV$. The computation is carried out in Type-1 2HDM. Here we consider the case of exact alignment limit ($s_{\beta \alpha}$ = 1) and masses of extra Higgs state are equal that is $m_H = m_{H^0} = m_{A^0} = m_{H^\pm}$. This choice is made to minimize the oblique parameters. The decays of the final state of each process are investigated to estimate the number of events at integrated luminosity of $1ab^{-1}$ and $3ab^{-1}$.