English

A tale of $Z$+jet: SMEFT effects and the Lam-Tung relation

High Energy Physics - Phenomenology 2025-05-07 v2 High Energy Physics - Experiment

Abstract

We derive constraints on dimension-six light-quark dipole operators within the Standard Model (SM) effective field theory, based on measurements of ZZ production at SLC and LEP, as well as ZZ+jet production at the LHC. Our new constraints exclude the parameter space that could potentially explain the observed discrepancy between theoretical predictions and experimental data for the Lam-Tung relation. With these updated limits, we model-independently determine the maximum possible influence that beyond-SM contributions could have on the angular coefficients A0A_0 and A2A_2, which enter the Lam-Tung relation.

Keywords

Cite

@article{arxiv.2412.13014,
  title  = {A tale of $Z$+jet: SMEFT effects and the Lam-Tung relation},
  author = {R. Gauld and U. Haisch and J. Weiss},
  journal= {arXiv preprint arXiv:2412.13014},
  year   = {2025}
}

Comments

25 pages, 7 figures; v2: revised and expanded version of the manuscript as accepted for publication in SciPost