Jet charge: A new tool to probe the anomalous [formula omitted] couplings at the EIC

Abstract

We propose to probe the Zbb¯ interactions at the Electron-Ion Collider (EIC) by utilizing the average jet charge weighted single-spin asymmetry AebQ, which is induced by different cross sections of a left-handed and right-handed electron beam scattering off an unpolarized proton beam in the neutral current deeply-inelastic scattering processes with one observed b-tagged jet. This novel observable at the EIC is sensitive to the axial-vector component of the Zbb¯ coupling, providing similar information as the gg→Zh cross section measurement at the high-luminosity Large Hadron Collider, and is complementary to the single-spin asymmetry measurement at the EIC which is sensitive to the vector component of the Zbb¯ coupling. We show that the apparent degeneracy of the allowed Zbb¯ coupling in its vector and axial-vector components, implied by the Large Electron-Positron Collider (LEP) and the Stanford Linear Collider (SLC) precision electroweak data, can be broken by the AebQ measurement at the EIC. With a large enough integrated luminosity collected at the EIC, the measurement of AebQ could also resolve the long-standing discrepancy between bottom quark forward-backward asymmetry AFBb at the LEP and the Standard Model prediction, with a strong dependence on the b-tagging efficiency.