Following the trail of new physics via VBF Higgs signal at the Large Hadron Collider

TL;DR

This paper explores how higher-dimensional operators in the Standard Model Effective Field Theory can modify Higgs signals from vector boson fusion at the LHC, identifying key kinematic variables to detect such effects.

Contribution

It introduces specific kinematic variables sensitive to dimension-6 operators in SMEFT and estimates the LHC's potential to probe these operators at high luminosity.

Findings

Identified geometric mean of jet transverse momenta as a key variable.

Proposed methods can improve limits on effective operator couplings.

Estimated LHC sensitivity to new physics effects in Higgs VBF signals.

Abstract

We investigate the modification of the Higgs signals from vector boson fusion at the LHC arising from higher-dimensional effective operators involving quarks, electroweak gauge bosons and the 125-GeV scalar discovered in 2012. Taking a few of the admissible dimension-6 operators as illustration, we work within the framework of the Standard Model Effective Field Theory (SMEFT) and identify kinematic variables that can reflect the presence of such effective operators. The useful variables turn out to be the geometric mean of the transverse momenta of the two forward jets produced in VBF and the rapidity difference between the two forward jets. We identify the shift in event population caused by the effective operators in the same, spanned by the above kinematic variables. Minimum values of the Wilson coefficients of the chosen dimension-6 operators are identified, for which they can be probed at the $3\sigma$ level in the high luminosity run of the LHC at 14 TeV. Projected exclusion limits on some of the couplings, obtained from our analysis, can significantly improve the limits on such couplings derived from electroweak precision data.