Analyzing t t ¯ Z -couplings at the future e − p collider
Year: 2025
Type: article
Abstract: The proposed Large Hadron electron Collider (LHeC), with a center-of-mass energy of s ≈ 1.3 TeV , provides a clean and sensitive environment to probe the top quark’s neutral current interactions with the Z boson via e − p → e − t t ¯ . We investigate the precision with which the Standard Model (SM) t t ¯ Z couplings—the vector and axial-vector components ( Δ C 1 V , Δ C 1 A ) can be measured, along with possible new physics effects parametrized by higher-dimensional operators inducing weak electric and magnetic dipolelike interactions ( C 2 V , C 2 A ). Focusing on the semileptonic decay channel, where either the top quark decays leptonically to a positively charged lepton ( ℓ + = e + , μ + ) and the antitop hadronically, or vice versa, we utilize the azimuthal angle difference Δ ϕ e − ℓ ± between the scattered electron and the charged lepton ℓ ± as the key observable to derive projected constraints. Using a one-parameter multibin χ 2 analysis of the differential Δ ϕ e − ℓ ± distribution, the constraints on Δ C 1 A improve from O ( 10 − 1 ) at 50 fb − 1 to O ( 10 − 2 ) at 1000 fb − 1 , while the improvement for Δ C 1 V remains within the same order of magnitude,
DOI: 10.1103/fp7y-m31y
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W4416933181