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.
Organisations
People |
ORCID iD |
| Sinead Farrington (Principal Investigator / Fellow) |
Publications
Aad G
(2012)
Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS
in Physics Letters B
Aad G
(2012)
Measurement of the isolated diphoton cross section in p p collisions at s = 7 TeV with the ATLAS detector
in Physical Review D
Aad G
(2011)
Measurement of dijet production with a veto on additional central jet activity in pp collisions at $ \sqrt {s} = 7 $ TeV using the ATLAS detector
in Journal of High Energy Physics
Aad G
(2012)
Measurement of the azimuthal anisotropy for charged particle production in s N N = 2.76 TeV lead-lead collisions with the ATLAS detector
in Physical Review C
Aad G
(2011)
Search for the Standard Model Higgs boson in the two photon decay channel with the ATLAS detector at the LHC
in Physics Letters B
Aad G
(2011)
Search for quark contact interactions in dijet angular distributions in pp collisions at s = 7 TeV measured with the ATLAS detector
in Physics Letters B
Aad G
(2012)
Measurement of W ± Z production in proton-proton collisions at $\sqrt{s}=7~\mbox{TeV}$ with the ATLAS detector
in The European Physical Journal C
Aad G
(2012)
Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC
in Physics Letters B
Aad G
(2011)
Limits on the production of the standard model Higgs boson in pp collisions at $\sqrt{s} = 7$ TeV with the ATLAS detector
in The European Physical Journal C
Aaltonen T
(2012)
Measurements of the angular distributions of muons from ? decays in pp collisions at sqrt[s] = 1.96 TeV.
in Physical review letters
Aaltonen T
(2013)
Evidence for a bottom baryon resonance ? b * 0 in CDF data
in Physical Review D
Aaltonen T
(2012)
Combination of CDF and D0 measurements of the W boson helicity in top quark decays
in Physical Review D
Aaltonen T
(2011)
Observation of the baryonic flavor-changing neutral current decay ?b(0)??µ+µ-.
in Physical review letters
Aaltonen T
(2013)
Search for the production of Z W and Z Z boson pairs decaying into charged leptons and jets in p p ¯ collisions at s = 1.96 TeV
in Physical Review D
Aaltonen T
(2011)
Search for New T' particles in final states with large jet multiplicities and missing transverse energy in p p collisions at sqrt[s] = 1.96 TeV.
in Physical review letters
Aaltonen T
(2013)
Measurement of the B c - meson lifetime in the decay B c - ? J / ? p -
in Physical Review D
Aaltonen T
(2011)
Measurement of polarization and search for CP violation in B(s)0?ff decays.
in Physical review letters
Aaltonen T
(2012)
Search for the standard model Higgs Boson produced in association with top quarks using the full CDF data set.
in Physical review letters
Aaltonen T
(2011)
Measurement of branching ratio and B s 0 lifetime in the decay B s 0 ? J / ? f 0 ( 980 ) at CDF
in Physical Review D
Aaltonen T
(2011)
Measurement of the B(s)0 lifetime in fully and partially reconstructed B(s)0?D(s)(-)(?p(-))X decays in p¯p collisions at vs=1.96 TeV.
in Physical review letters
Aaltonen T
(2011)
Search for resonant production of t t ¯ pairs in 4.8 fb - 1 of integrated luminosity of p p ¯ collisions at s = 1.96 TeV
in Physical Review D
Aaltonen T
(2011)
Search for B(s)(0) ? µ+ µ- and B(0) ? µ+ µ- decays with CDF II.
in Physical review letters
Aaltonen T
(2012)
Measurement of C P -violation asymmetries in D 0 ? K S 0 p + p -
in Physical Review D
Aaltonen T
(2013)
Observation of the production of a W boson in association with a single charm quark.
in Physical review letters
Aaltonen T
(2013)
Measurement of W -boson polarization in top-quark decay using the full CDF Run II data set
in Physical Review D
Aaltonen T
(2013)
Higgs boson studies 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)
Study of substructure of high transverse momentum jets produced in proton-antiproton collisions at s = 1.96 TeV
in Physical Review D
Aaltonen T
(2011)
Top-quark mass measurement using events with missing transverse energy and jets at CDF.
in Physical review letters
Aaltonen T
(2011)
Search for a heavy toplike quark in pp collisions at vs=1.96 TeV.
in Physical review letters
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
Aaltonen T
(2012)
Evidence for the charmless annihilation decay mode B(s)(0)?p(+)p(-).
in Physical review letters
Aaltonen T
(2012)
Diffractive dijet production in p ¯ p collisions at s = 1.96 TeV
in Physical Review D
Aaltonen T
(2013)
Signature-based search for delayed photons in exclusive photon plus missing transverse energy events from p p ¯ collisions with s = 1.96 TeV
in Physical Review D
Aaltonen T
(2013)
Measurement of the cross section for prompt isolated diphoton production using the full CDF run II data sample.
in Physical review letters
Aaltonen T
(2012)
Combination of the top-quark mass measurements from the Tevatron collider
in Physical Review D
Aaltonen T
(2013)
Updated search for the standard model Higgs boson in events with jets and missing transverse energy using the full CDF data set
in Physical Review D
Aaltonen T
(2012)
Search for a heavy vector boson decaying to two gluons in p p ¯ collisions at s = 1.96 TeV
in Physical Review D
Aaltonen T
(2012)
Production of ? 0 , ? ¯ 0 , ? ± , and O ± hyperons in p p ¯ collisions at s = 1.96 TeV
in Physical Review D
Aaltonen T
(2012)
An additional study of multi-muon events produced in p p ¯ collisions at s = 1.96 TeV
in Physics Letters B
Aaltonen T
(2012)
Search for heavy metastable particles decaying to jet pairs in p p ¯ collisions at s = 1.96 TeV
in Physical Review D
Aaltonen T
(2011)
Search for new physics in high pT like-sign dilepton events at CDF II.
in Physical review letters
Aaltonen T
(2012)
Search for a low-mass standard model Higgs boson in the tt decay channel in pp 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
(2012)
Search for a heavy particle decaying to a top quark and a light quark in pp ¯ collisions at vs=1.96 TeV.
in Physical review letters
Aaltonen T
(2012)
Precise measurement of the W-boson mass with the CDF II detector.
in Physical review letters
Aaltonen T
(2013)
Indirect measurement of sin ? 2 ? W ( M W ) using e + e - pairs in the Z -boson region with p p ¯ collisions at a center-of-momentum energy of 1.96 TeV
in Physical Review D
Aaltonen T
(2011)
Search for the Higgs boson in the all-hadronic final state using the CDF II detector
in Physical Review D
Aaltonen T
(2013)
Production of K S 0 , K * ± ( 892 ) and ? 0 ( 1020 ) in minimum bias events and K S 0 and ? 0 in jets in p p ¯ collisions at s = 1.96 TeV
in Physical Review D
Related Projects
| Project Reference | Relationship | Related To | Start | End | Award Value |
|---|---|---|---|---|---|
| PP/E003699/1 | 30/09/2007 | 31/05/2011 | £431,354 | ||
| PP/E003699/2 | Transfer | PP/E003699/1 | 31/05/2011 | 29/09/2012 | £118,160 |
| Description | Higgs boson searches for tau leptons yielded observation in 2015. |
| Exploitation Route | Fundamental science understanding. |
| Sectors | Other |