# Jet Substructure Measurements of Interference in Non-Interfering SMEFT Effects

## TL;DR

This paper investigates how jet substructure techniques can detect interference effects in diboson production at the LHC, especially for non-interfering SMEFT operators, by measuring azimuthal decay angles to enhance sensitivity.

## Contribution

It introduces a novel method using jet substructure to measure azimuthal decay angles, revealing interference effects of non-interfering SMEFT operators in hadronic W decays.

## Key findings

- Azimuthal angles can resurrect interference sensitivity in non-interfering operators.
- An asymmetry variable suppresses higher-dimensional operator uncertainties.
- Jet substructure techniques effectively measure azimuthal decay angles.

## Abstract

The tails of diboson production at the LHC are sensitive to the interference between Standard Model and higher dimension operators parameterizing the effects of heavy new physics. However, helicity selection rules for the diboson scattering amplitudes set an obstruction to the na\"ive interference contributions of dimension six operators, causing the total diboson rate correction's leading contribution to cancel. In this case, carefully measuring the azimuthal decay angles "resurrects" the interference, recouping sensitivity to the "non-interfering" operators. We explore these signatures in detail, and find that the EFT uncertainties associated with higher-dimensional operators are uniquely well-suppressed by the construction of an asymmetry variable which is only generated by these non-interfering operators, relegating the effects of higher-dimensional, interfering operators to the same status as statistical errors in this observable. We perform a complete analysis of this azimuthal interference pattern in hadronic decays of W bosons using jet substructure techniques to tag the bosons and measure their azimuthal decay angles. This technique provides a valuable cross-check to purely-leptonic measurements of interference resurrection in diboson production.