Studying the VBF Hjj and Hjjj Higgs Boson Production in QCD and EFT Theory
This paper models the kinematic properties and calculates the production cross-sections of Higgs bosons in association with two and three jets (Hjj and Hjjj) via vector boson fusion, utilizing both QCD and Effective Field Theory frameworks across Standard Model, MSSM, and NMSSM scenarios.
Original paper licensed under CC BY 4.0 (http://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Imagine the universe as a giant, chaotic dance floor where tiny particles zoom around, bumping into each other at incredible speeds. Physicists are the detectives trying to figure out the rules of this dance. For a long time, they had a "rulebook" called the Standard Model, which explained almost everything they saw. But in 2012, they found a new dancer on the floor: the Higgs boson. This particle is special because it's the reason other particles have mass, kind of like how a celebrity walking through a crowded room makes people slow down and stick to them. Now that we know the Higgs exists, the big question is: how does it dance? Does it follow the old rulebook perfectly, or is it doing secret moves that hint at a whole new set of rules (called "Beyond the Standard Model" or BSM) that we haven't discovered yet? To find out, scientists smash protons together in massive machines called colliders, looking for specific patterns where the Higgs appears alongside other particles, like jets of debris.
This paper is a detailed simulation of one of those specific dance moves: the Higgs boson being born alongside two or three jets of particles, created through a process called "Vector Boson Fusion" (VBF). Think of VBF as two protons passing each other, throwing out a pair of weak force carriers (like invisible tennis rackets) that collide to create the Higgs, while the protons themselves fly off in opposite directions, leaving behind two jets. The authors of this paper used powerful computer programs to model this event under different theoretical scenarios. They didn't just look at the standard rules; they also tested "what-if" scenarios involving supersymmetry (a theory suggesting every particle has a heavier partner) and effective field theory (a mathematical shortcut to describe physics at different energy scales). Their goal was to calculate exactly how often these events happen (the "cross-section") and see if the numbers change depending on which theory is true.
The main finding of this study is that while the standard rules work, the "what-if" scenarios predict slightly different numbers. Specifically, when they simulated the Higgs appearing with two jets (Hjj) or three jets (Hjjj), they found that the NMSSM model (a specific version of the supersymmetry theory) consistently produced the highest number of events across all the energy levels they tested (13, 14, and even a hypothetical 100 TeV). For example, at an energy of 13 TeV and a jet mass of 400 GeV, the NMSSM model predicted a cross-section of 2.16 ± 0.012, which is higher than the Standard Model's 1.735 ± 0.009. The authors also compared their standard calculations with a newer approach called Effective Field Theory (EFT). They found that the results were almost identical, except for one specific case: at 13 TeV with a jet mass of 600 GeV, the EFT approach showed a noticeable increase in the Standard Model's cross-section compared to their standard calculations.
The paper also looked at the "three-jet" version of this dance (Hjjj). Here, the rules of the game get stricter because adding a third jet makes the event much rarer. The simulations showed that the cross-section for these three-jet events is about two orders of magnitude smaller than the two-jet events. For instance, at 13 TeV with a 400 GeV mass, the two-jet process had a cross-section around 1.7, while the three-jet process dropped to just 0.0056. This confirms that adding that third jet acts like a very strong filter, making these events much harder to spot but potentially very clean for spotting new physics. The authors also checked the "rapidity" (a measure of how far forward or backward the particles fly) and transverse momentum (how hard they move sideways), finding that the events are "peripheral," meaning the jets tend to fly off to the sides of the detector rather than straight through the middle.
In the end, the authors conclude that their simulations match the order of magnitude of other scientists' work, giving them confidence in their numbers. They didn't prove that the NMSSM model is the correct description of the universe, but their simulations suggest that if new physics exists, the NMSSM model is a strong candidate because it predicts the most frequent Higgs production in these specific jet scenarios. They also noted that the Effective Field Theory approach is a flexible and useful tool, though it showed a slight deviation from standard calculations at higher masses. Ultimately, this work provides a refined map for future experiments, telling physicists exactly where to look and what numbers to expect if they want to catch the Higgs boson doing its most complex dance moves.
Drowning in papers in your field?
Get daily digests of the most novel papers matching your research keywords — with technical summaries, in your language.