New physics and signal-background interference in associated pp → HZ production

Inclusive Higgs measurements at the LHC have limited resolution on the gluon fusion loops, being unable to distinguish the long-distance contributions mediated by the top quark from possible short-distance new physics effects. Using an Effective Field Theory (EFT) approach we compare several proposed methods to lift this degeneracy, including tth and boosted, off-shell and double Higgs production, and perform detailed projections to the High-Luminosity LHC and a future hadron collider. In addition, we revisit off-shell Higgs production. Firstly, we point out its sensitivity to modifications of the top-Z couplings, and by means of a general analysis we show that the reach is comparable to that of treelevel processes such as ttZ production. Implications for composite Higgs models are also discussed. Secondly, we assess the regime of validity of the EFT, performing an explicit comparison for a simple extension of the Standard Model containing one vector-like quark.

Section: Jhep09(2016)123supporting

confidence: 67%

Section: Comparison To Other Gluon-fusion Processescontrasting

confidence: 53%

Section: Jhep09(2016)123mentioning

confidence: 99%

Section: Comparison To Other Gluon-fusion Processesmentioning

confidence: 99%

See 2 more Smart Citations

Resolving gluon fusion loops at current and future hadron colliders

Azatov

Grojean²,

Paul

et al. 2016

“…We leave instead a detailed phenomenological analysis for future work. For recent phenomenological work in the area a surely incomplete list is [20][21][22][23][24][25].…”

Section: Jhep06(2016)107mentioning

confidence: 99%

Gauge theories of partial compositeness: scenarios for Run-II of the LHC

Ferretti

2016

136

193

We continue our investigation of gauge theories in which the Higgs boson arises as a pseudo-Nambu-Goldstone boson (pNGB) and top-partners arise as bound states of three hyperfermions. All models have additional pNGBs in their spectrum that should be accessible at LHC. We analyze the patterns of symmetry breaking and present all relevant couplings of the pNGBs with the gauge fields. We discuss how vacuum misalignment and a mass for the pNGBs is generated by a loop-induced potential. Finally, we paint a very broad, qualitative, picture of the kind of experimental signatures these models give rise to, setting the stage for further analysis.

Top, Higgs, diboson and electroweak fit to the Standard Model effective field theory

Ellis

Madigan

Mimasu

et al. 2021

200

167

The search for effective field theory deformations of the Standard Model (SM) is a major goal of particle physics that can benefit from a global approach in the framework of the Standard Model Effective Field Theory (SMEFT). For the first time, we include LHC data on top production and differential distributions together with Higgs production and decay rates and Simplified Template Cross-Section (STXS) measurements in a global fit, as well as precision electroweak and diboson measurements from LEP and the LHC, in a global analysis with SMEFT operators of dimension 6 included linearly. We present the constraints on the coefficients of these operators, both individually and when marginalised, in flavour-universal and top-specific scenarios, studying the interplay of these datasets and the correlations they induce in the SMEFT. We then explore the constraints that our linear SMEFT analysis imposes on specific ultra-violet completions of the Standard Model, including those with single additional fields and low-mass stop squarks. We also present a model-independent search for deformations of the SM that contribute to between two and five SMEFT operator coefficients. In no case do we find any significant evidence for physics beyond the SM. Our underlying Fitmaker public code provides a framework for future generalisations of our analysis, including a quadratic treatment of dimension-6 operators.