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Quartic Higgs self-coupling at a 100 TeV pp collider

Grabowski, Sebastian LU (2021) FYTM03 20202
Theoretical Particle Physics
Abstract
We present a parton-level phenomenological study of triple-Higgs production at leading order in proton-proton collisions at a center-of-mass energy of 100 TeV with an integrated luminosity of 30 ab^-1. This study aims to estimate the prospects for measuring the signal hhh production observable at the Future Circular Collider. We explore interesting final states that could be used for this purpose and focus our study on the hhh→γγbbbb final state. We construct a baseline analysis and investigate the signal sensitivity to simple deformations of the Higgs potential in the presence of the dominating non-resonant background. From this, we are able to demonstrate the sensitivity of the pp→hhh→γγbbbb process to quartic Higgs coupling.
Popular Abstract
The existence of the Higgs boson was confirmed in 2012, adding the last missing puzzle piece to the Standard Model of Particle Physics, our most accurate description of interactions between the fundamental building blocks of nature. However, even though the Higgs boson's mass has been measured, there are still open questions left to address. One of these questions is how the Higgs boson interacts with itself.

What we can learn about the Higgs self-interaction is directly linked to the so-called electroweak symmetry breaking mechanism, which allows the electroweak bosons (W^± and Z^0 bosons) to become massive. For the mechanism to work, there must exist both three- and four-particle interaction couplings for the Higgs boson, yet to be... (More)
The existence of the Higgs boson was confirmed in 2012, adding the last missing puzzle piece to the Standard Model of Particle Physics, our most accurate description of interactions between the fundamental building blocks of nature. However, even though the Higgs boson's mass has been measured, there are still open questions left to address. One of these questions is how the Higgs boson interacts with itself.

What we can learn about the Higgs self-interaction is directly linked to the so-called electroweak symmetry breaking mechanism, which allows the electroweak bosons (W^± and Z^0 bosons) to become massive. For the mechanism to work, there must exist both three- and four-particle interaction couplings for the Higgs boson, yet to be measured. Their values have profound implications for Beyond the Standard Model physics and cosmology, particularly to the phase transition where the two, electromagnetic and weak, forces become separated in the early universe. So, a comparison of the measured and predicted Higgs boson self-interaction couplings provides the ultimate test of the Standard Model and its extensions.

This task is a difficult one, as we need to experimentally observe the production of several Higgs bosons in the same collision - a rare occurrence to say at least - and to make sure that they are produced from an intermediate Higgs boson, due to a self-interaction, rather than radiated from other particles. Experimentally, these two types of production are indistinguishable. Indeed there is no way of knowing what has occurred after the primary collision by detecting the shower of final-state particles in our detectors. Thus, one would need to measure the production precisely to compare it to theoretical predictions to understand how much of the signal comes due to the Higgs self-interactions. However, measuring the three-Higgs self-interaction at the LHC might not be possible, and previous studies have shown that the four-Higgs vertices are beyond our current grasp at the LHC as well.

There is still hope for determining the coupling strengths at the recently proposed post-LHC particle accelerator called the Future Circular Collider. At its collision energy of 100 TeV, it is believed that a precise measurement of Higgs self-interaction can be achieved. As for now, we need to develop a strategy for extracting this information about the couplings from the corresponding observables. There exist many difficulties along the way, and with this study, we will determine how feasible such an analysis would be. (Less)
Please use this url to cite or link to this publication:
author
Grabowski, Sebastian LU
supervisor
organization
course
FYTM03 20202
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Quartic Higgs self-coupling, Triple Higgs production, Future Circular Collider, FCC, MadGraph, MadAnalysis, Events selection, selection strategy
language
English
id
9038189
date added to LUP
2021-01-29 15:59:54
date last changed
2021-01-29 15:59:54
@misc{9038189,
  abstract     = {{We present a parton-level phenomenological study of triple-Higgs production at leading order in proton-proton collisions at a center-of-mass energy of 100 TeV with an integrated luminosity of 30 ab^-1. This study aims to estimate the prospects for measuring the signal hhh production observable at the Future Circular Collider. We explore interesting final states that could be used for this purpose and focus our study on the hhh→γγbbbb final state. We construct a baseline analysis and investigate the signal sensitivity to simple deformations of the Higgs potential in the presence of the dominating non-resonant background. From this, we are able to demonstrate the sensitivity of the pp→hhh→γγbbbb process to quartic Higgs coupling.}},
  author       = {{Grabowski, Sebastian}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Quartic Higgs self-coupling at a 100 TeV pp collider}},
  year         = {{2021}},
}