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arXiv · 2412.13014

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

R. Gauld·U. Haisch·J. Weiss
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Abstract

We derive constraints on dimension-six light-quark dipole operators within the Standard Model (SM) effective field theory, based on measurements of $Z$ production at SLC and LEP, as well as $Z$+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 $A_0$ and $A_2$, which enter the Lam-Tung relation.

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R. Gauld, U. Haisch, J. Weiss. 2024-12-17. A tale of $Z$+jet: SMEFT effects and the Lam-Tung relation. https://doi.org/10.21468/scipostphys.18.5.148

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