Leptophobic Z' Boson and Parity-Violating eD Scattering

TL;DR

This paper investigates how a leptophobic Z' boson influences parity-violating electron-quark interactions, including one-loop corrections, and assesses the potential for future experiments to detect such effects, especially in light of the CDF W plus di-jet anomaly.

Contribution

It provides a comprehensive, model-independent analysis of leptophobic Z' effects on low-energy parity violation, including penguin-like vertex corrections, and explores implications for specific Z' scenarios.

Findings

Flavor non-diagonal couplings are constrained by kaon and heavy flavor studies.

A light Z' with flavor-diagonal couplings to up or down quarks does not affect C_{1q} but impacts C_{2q}.

Future parity-violating deep inelastic scattering experiments can probe these effects.

Abstract

We study the impact of a leptophobic Z' gauge boson on the C_{1q} and C_{2q} parameters that describe the low-energy, parity-violating electron-quark neutral current interaction. We complement previous work by including the penguin-like vertex corrections, thereby completing the analysis of one-loop calculation up to O(m^2_q'/M^2_Z') terms. We analyze the sensitivity of these probes to the different couplings Z'\bar{u}q (q=u,c,t) and Z'\bar{d}q (q=d,s,b), in a model-independent way that can be applied to any specific Z' scenario. We show that constraints from neutral kaon and heavy flavor studies preclude significant contributions from flavor non-diagonal couplings except for those involving top quarks. We apply our results to a light Z' with flavor diagonal couplings to up or down quarks, a scenario proposed in the literature to explained the CDF W plus di-jet anomaly. We find that such a particle would not affect the C_{1q} coefficients, but it would have a sizable impact on C_{2q} couplings that can be probed by future measurements of parity-violating deep inelastic scattering of polarized electrons off of deuterium.