Jet Charge: A new tool to probe the anomalous $Zb\bar{b}$ couplings at the EIC

TL;DR

This paper introduces a new observable, jet charge weighted asymmetry, at the EIC to precisely probe the $Zb\bar{b}$ couplings, potentially resolving existing anomalies and complementing other measurements.

Contribution

It proposes a novel jet charge asymmetry measurement at the EIC to improve constraints on $Zb\bar{b}$ couplings and resolve existing electroweak anomalies.

Findings

The observable is sensitive to the axial-vector component of $Zb\bar{b}$ coupling.

Measurement can break degeneracy in $Zb\bar{b}$ coupling parameters.

Potential to resolve the $A_{FB}^b$ discrepancy at LEP.

Abstract

We propose to utilize the average jet charge weighted single-spin asymmetry $A_e^{bQ}$ in the neutral current DIS scattering with one $b$-tagged jet produced at the EIC to probe the $Zb\bar{b}$ interactions. This novel observable is sensitive to the axial-vector component of the $Zb\bar{b}$ coupling and is complementary to the single-spin asymmetry measurement at the EIC and the $gg\to Zh$ cross section measurement at the HL-LHC in the determination of the $Zb\bar{b}$ couplings. We show that the apparent degeneracy of the $Zb\bar{b}$ couplings, implied by the LEP and SLC precision electroweak data, can be broken by the $A_e^{bQ}$ measurement at the EIC. With a large enough integrated luminosity collected at the EIC, the measurement of $A_e^{bQ}$ could also resolve the long-standing discrepancy of $A_{\rm FB}^b$ at the LEP, strongly dependent on the $b$-tagging efficiency.