Search for the Higgs Boson at the ATLAS Experiment
Lead Research Organisation:
University of Warwick
Department Name: Physics
Abstract
Over a century of study has led physicists to develop the Standard Model theory (SM) of the building blocks of matter and the forces among them. This combines the strong force which binds quarks into nuclei, the weak force which explains radioactivity and the electromagnetic force which holds electrons in atoms. To date, it is the most accurately tested scientific theory, verified to a few parts per billion! Given this amazing success you may wonder why scientists have any doubts about the theory. However, one piece is missing: understanding the generation of mass. Despite all of the SM's testable predictions, it cannot predict any particle's mass (and by extension cannot explain your or my weight). This challenge inspires theories ranging from tweaks of the SM, to more outlandish, but possibly true, theories which require a plethora of new particles, possibly accounting for dark matter. In 1964 Peter Higgs, now Edinburgh professor emeritus, proposed an elegant solution to the mass generation problem requiring only one new particle. This 'boson' grabs hold of other particles and the stronger it holds on, the heavier they become. The eponymous Higgs boson has been a holy grail of fundamental science ever since. Although the Higgs boson was devised to generate mass, its own mass is unspecified. Scientists worldwide have searched for it unsuccessfully, ruling out large mass ranges and driving the search to increasingly high energies. Evidence from other precision data now predicts that if the SM Higgs boson exists, it can be found at the Large Hadron Collider (LHC) at the European Centre for Particle Physics (CERN) which will collide protons in a 27km underground ring at unprecedented energies in 2008. There, we should find the long-awaited SM Higgs boson or, possibly, a boson with unexpected properties revealing that more complex dynamics occur in nature, prompting an entire re-think or extension of the SM. If it exists, my proposed programme will discover the SM Higgs boson in the experimentally favoured low mass range. If not, I may find nature's Higgs surrogate. My careful study will identify which of these scenarios is realised. I will search data from the ATLAS experiment at LHC, analysing 10 billion catalogued collisions, a task likened to finding one phone number in a 1000 directories. However, this is no random search since we know how to look for this 'number': we can do the equivalent of finding out the person's surname by looking for known characteristics of the Higgs boson in data! Theoretical understanding of the boson and experimental skill will pinpoint it in the midst of the maelstrom of activity in energetic proton collisions. I will build and lead a team in the Oxford ATLAS group to find the Higgs boson in its decay to two tau leptons or bottom quarks. With careful analysis of the data, these will provide distinctive experimental fingerprints. Simulations show that these decays will yield the five statistical standard deviations 'gold standard' of convincing discovery. The combination of the group's expertise and my in-depth experience from the USA's Tevatron collider will provide a firm foundation for each member of the team to study one element of the signature. For example by homing in on datasets which contain signatures of known particles which decay like the Higgs boson, the identification algorithms can be honed. Finding the tau lepton or bottom quark requires algorithms which I will base on my experience of precision measurements in the bottom quark sector. These studies will characterise the ATLAS hardware enabling us to search the phonebooks of nature which the experiment provides. We cannot be sure that the Standard Model Higgs boson exists, but we can be certain that the hunt for the Higgs will be a fascinating journey whose destination may prove Peter Higgs right, or even more excitingly, that nature is richer and more complex than he imagined.
People |
ORCID iD |
Sinead Farrington (Principal Investigator / Fellow) |
Publications
Aaltonen T
(2012)
Search for anomalous production of multiple leptons in association with W and Z bosons at CDF
in Physical Review D
Aaltonen T
(2012)
Search for a Higgs boson in the diphoton final state using the full CDF data set from p p ¯ collisions at s = 1.96 TeV
in Physics Letters B
Aaltonen T
(2012)
Search for neutral Higgs bosons in events with multiple bottom quarks at the Tevatron
in Physical Review D
Aaltonen T
(2013)
Measurement of the cross section for direct-photon production in association with a heavy quark in pp[over ¯] collisions at sqrt[s]=1.96 TeV.
in Physical review letters
Aaltonen T
(2012)
Measurement of the top quark mass in the all-hadronic mode at CDF
in Physics Letters B
Aaltonen T
(2013)
Search for a two-Higgs-boson doublet using a simplified model in pp collisions at sqrt[s] = 1.96 TeV.
in Physical review letters
ANNOVI A
(2012)
Searches for physics beyond the Standard Model at the Tevatron
in Pramana
ATLAS Collaboration
(2012)
Measurement of the charge asymmetry in top quark pair production in pp collisions at [Formula: see text] using the ATLAS detector.
in The European physical journal. C, Particles and fields
ATLAS Collaboration
(2013)
Measurement of kT splitting scales in W?l? events at [Formula: see text] with the ATLAS detector.
in The European physical journal. C, Particles and fields
ATLAS Collaboration
(2012)
A particle consistent with the Higgs boson observed with the ATLAS detector at the Large Hadron Collider.
in Science (New York, N.Y.)
ATLAS Collaboration
(2012)
A search for [Formula: see text] resonances with the ATLAS detector in 2.05 fb-1 of proton-proton collisions at [Formula: see text].
in The European physical journal. C, Particles and fields
ATLAS Collaboration
(2013)
Multi-channel search for squarks and gluinos in [Formula: see text]pp collisions with the ATLAS detector at the LHC.
in The European physical journal. C, Particles and fields
ATLAS Collaboration
(2013)
Improved luminosity determination in pp collisions at [Formula: see text] using the ATLAS detector at the LHC.
in The European physical journal. C, Particles and fields
ATLAS Collaboration
(2012)
Search for lepton flavour violation in the eµ continuum with the ATLAS detector in [Formula: see text]pp collisions at the LHC.
in The European physical journal. C, Particles and fields
ATLAS Collaboration
(2012)
Measurement of [Formula: see text] production with a veto on additional central jet activity in pp collisions at [Formula: see text] TeV using the ATLAS detector.
in The European physical journal. C, Particles and fields
ATLAS Collaboration
(2012)
Measurement of t polarization in W?t? decays with the ATLAS detector in pp collisions at [Formula: see text].
in The European physical journal. C, Particles and fields
ATLAS Collaboration
(2013)
Measurement of jet shapes in top-quark pair events at [Formula: see text] using the ATLAS detector.
in The European physical journal. C, Particles and fields
ATLAS Collaboration
(2011)
Measurement of the inelastic proton-proton cross-section at vs=7 TeV with the ATLAS detector.
in Nature communications
ATLAS Collaboration
(2013)
Jet energy resolution in proton-proton collisions at [Formula: see text] recorded in 2010 with the ATLAS detector.
in The European physical journal. C, Particles and fields
ATLAS Collaboration
(2012)
Measurement of the top quark mass with the template method in the [Formula: see text] channel using ATLAS data.
in The European physical journal. C, Particles and fields
ATLAS Collaboration
(2013)
Measurement of the inclusive jet cross-section in pp collisions at [Formula: see text] and comparison to the inclusive jet cross-section at [Formula: see text] using the ATLAS detector.
in The European physical journal. C, Particles and fields
Collaboration T
(2008)
The ATLAS Experiment at the CERN Large Hadron Collider
in Journal of Instrumentation
Collaboration T
(2012)
A study of the material in the ATLAS inner detector using secondary hadronic interactions
in Journal of Instrumentation
Davies G
(2013)
Higgs boson searches at the Tevatron
in Frontiers of Physics
G. And Others
Performance of the ATLAS b-tagging algorithms
G. And Others
Search for t anti-t H(H --- b anti-b)
The ATLAS Collaboration
(2012)
Search for doubly charged Higgs bosons in like-sign dilepton final states at $\sqrt{s} = 7\ \mathrm{TeV}$ with the ATLAS detector
in The European Physical Journal C
The ATLAS Collaboration
(2012)
ATLAS search for a heavy gauge boson decaying to a charged lepton and a neutrino in pp collisions at $\sqrt{s} = 7\ \mathrm{TeV}$
in The European Physical Journal C
The ATLAS Collaboration
(2012)
Search for heavy neutrinos and right-handed W bosons in events with two leptons and jets in pp collisions at [Formula: see text] with the ATLAS detector.
in The European physical journal. C, Particles and fields
The ATLAS Collaboration
(2013)
Search for a light charged Higgs boson in the decay channel [Formula: see text] in [Formula: see text] events using pp collisions at [Formula: see text] with the ATLAS detector.
in The European physical journal. C, Particles and fields
Description | Higgs boson searches for tau leptons yielded observation in 2015. |
Exploitation Route | Fundamental science understanding. |
Sectors | Other |