| phenomenon | Standard Model Higgs boson search— “The search for the Higgs boson, the only elementary particle in the SM that has not yet been observed, is one of the highlights of the Large Hadron Collider [11] (LHC) physics programme.” |
| claim-type | existence— “The largest local significance for the combination of the 7 and 8 TeV data is found for a SM Higgs boson mass hypothesis of mH=126.5 GeV, where it reaches 6.0 σ, with an expected value in the presence of a SM Higgs boson signal at that mass of 4.9 σ (see also Table 7).” |
| method — evidence | — “A search for the Standard Model Higgs boson in proton-proton collisions with the ATLAS detector at the LHC is presented.” |
| transfer | from statistics (hypothesis testing, p-values): statistical significance testing (p-values, sigma levels) used to establish the discovery of a new particle against background fluctuations— “the p-values corresponding to significances of 1 to 6” | transfers[0] |
| mechanism | the whole search is reduced to ONE parameter of interest - a signal strength that scales the predicted signal - and it is defined so that zero is the background-only hypothesis and one is the Standard Model Higgs signal, so the hypothesis under test is a value of that one factor— “The parameter of interest is the global signal strength factor µ, which acts as a scale factor on the total number of events predicted by the Standard Model for the Higgs boson signal. This factor is defined such that µ = 0 corresponds to the background-only hypothesis and µ = 1 corresponds to the SM Higgs boson signal in addition to the… | mechanisms[0] |
| mechanism | hypothesised values of that strength are tested with a profile likelihood ratio, which extracts the signal strength from a full likelihood fit whose function INCLUDES all the parameters describing the systematic uncertainties and their correlations— “Hypothesised values of µ are tested with a statistic λ(µ) based on the profile likelihood ratio [122]. This test statistic extracts the information on the signal strength from a full likelihood fit to the data. The likelihood function includes all the parameters that describe the systematic uncertainties and their correlations.” | mechanisms[1] |
| mechanism | exclusion is decided by a stated numerical rule rather than by judgement: a signal strength is excluded at 95% confidence when its CLs value falls below 5%, and a Standard Model Higgs of a given mass counts as excluded when the value one is excluded at that mass— “Exclusion limits are based on the CLs prescription [123]; a value of µ is regarded as excluded at 95% CL when CLs is less than 5%. A SM Higgs boson with mass mH is considered excluded at 95% confidence level (CL) when µ = 1 is excluded at that mass.” | mechanisms[2] |
| mechanism | the size of an excess is first expressed as the probability that background alone could produce a fluctuation at least that large, and only then converted into the equivalent number of standard deviations - the local significance— “The significance of an excess in the data is first quantified with the local p0, the probability that the background can produce a fluctuation greater than or equal to the excess observed in data. The equivalent formulation in terms of number of standard deviations, Zl, is referred to as the local significance.” | mechanisms[3] |
| mechanism | that local number is then corrected for having searched a whole mass range rather than one point: the ratio of global to local probability is the trials factor, and the paper states what it depends on - the range of hypotheses considered, the mass resolutions of the channels combined, and the size of the excess itself— “The global probability for the most significant excess to be observed anywhere in a given search region is estimated with the method described in Ref. [124]. The ratio of the global to the local probabilities, the trials factor used to correct for the ”look elsewhere” effect, increases with the range of Higgs boson mass hypotheses considered… | mechanisms[4] |
| mechanism | the tests are run in steps across the hypothesised mass rather than at one chosen point, and the asymptotic approximation the results rest on is not assumed to hold - it is validated by a separately described method— “The statistical tests are performed in steps of values of the hypothesised Higgs boson mass mH. The asymptotic approximation [122] upon which the results are based has been validated with the method described in Ref. [17].” | mechanisms[5] |
| mechanism | the combination across channels is built on the same single signal strength together with an explicit identification of which nuisance parameters correspond to the CORRELATED sources of systematic uncertainty— “The combination of individual search sub-channels for a specific Higgs boson decay, and the full combination of all search channels, are based on the global signal strength factor µ and on the identification of the nuisance parameters that correspond to the correlated sources of systematic uncertainty described in Section 8.” | mechanisms[6] |
| mechanism | the jet energy scale and resolution are handled by a deliberately simplified scheme - independent nuisance parameters attached to final states with materially different selections and process sensitivity - and the simplification is defended by measurement: the results were found insensitive to the assumptions made about how those sources correlate— “A simplified scheme is used in which independent JES and JER nuisance parameters are associated with final states with significantly different kinematic selections and sensitivity to scattering processes with different kinematic distributions or flavour composition. This scheme includes a specific treatment for b-jets. The sensitivity of the… | mechanisms[7] |
| builds-on | the Standard Model Higgs prediction— “compatible with the production and decay of the Standard Model” | claim_relations[0] |
| extends | the previous ATLAS H->ZZ(*)->4l analysis, Ref. [83]— “The analysis is improved in several aspects with respect to Ref. [83] to enhance the sensitivity to a low-mass Higgs boson.” | claim_relations[1] |
| sense | local significance - the number of standard deviations corresponding to the background producing a fluctuation at least as large as the excess observed, at one mass— “The equivalent formulation in terms of number of standard deviations, Zl, is referred to as the local significance.” | senses[0] |
| sense | global significance - the same excess corrected for having searched a whole mass range, which lowers 5.9 sigma to approximately 5.1 sigma over 110-600 GeV— “The global significance of a local 5.9 σ excess anywhere in the mass range 110–600 GeV is estimated to be approximately 5.1” | senses[1] |
| sense | trials factor - the ratio of global to local probability, larger the wider the range of hypotheses searched— “The ratio of the global to the local probabilities, the trials factor used to correct for the ”look elsewhere” effect, increases with the range of Higgs boson mass hypotheses considered, the mass resolutions of the channels involved in the combination, and the significance of the excess.” | senses[2] |
| control | control and validation regions built with the signal-region selections but with criteria reversed or modified, so the samples are depleted of signal — held — rules out a background estimate taken from the same events as the signal - the reversed criteria give regions where the signal cannot be, and the background can therefore be measured rather than assumed— “The control and validation regions are defined by selections similar to those used for the signal region but with some criteria reversed or modified to obtain signaldepleted samples enriched in a particular background.” | controls[0] |
| control | validation regions kept separate from the control regions used to normalise the backgrounds, with the paper stating which does which — held — rules out checking the background model on the very regions that were used to fit it - the distinction is what keeps the check independent of the fit— “The term “validation region” distinguishes these regions from the control regions that are used to directly normalise the backgrounds.” | controls[1] |
| control | data-driven estimation of the numbers of two-photon, photon-jet and jet-jet events in the selected sample — held — rules out reliance on simulation for the backgrounds hardest to simulate - jets faking photons is precisely where Monte Carlo is least trusted, so that component is measured from data— “Data-driven techniques [98] are used to estimate the numbers of γγ, γ j and j j events in the selected sam- 8 → ple.” [checked against the archived source, not this rendering] | controls[2] |
| control | a trials factor applied to convert the local probability to a global one, correcting for the range of Higgs mass hypotheses searched — held — rules out having looked in many places and reported the luckiest - the look-elsewhere correction is what makes the quoted significance a statement about the search rather than about one bin— “The ratio of the global to the local probabilities, the trials factor used to correct for the ”look elsewhere” effect, increases with the range of Higgs boson mass hypotheses considered, the mass resolutions of the channels involved in the combination, and the significance of the excess.” | controls[3] |
| audit | global significance —distinct-from→ local significance — Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but the span reports the global significance of a local excess; distinct-from is loose.— “The global significance of a local 5.9 σ excess anywhere in the mass range 110–600 GeV is estimated to be approximately 5.1” | concept_edges[0] |
| audit | trials factor —part-of→ global significance — Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but the trials factor is the RATIO of global to local probabilities, used to correct; part-of is loose.— “The ratio of the global to the local probabilities, the trials factor used to correct for the ”look elsewhere” effect, increases with the range of Higgs boson mass hypotheses considered, the mass resolutions of the channels involved in the combination, and the significance of the excess.” | concept_edges[1] |
| outcome (stated by the tagger, no quotation) | control — held | controls[0] |
| outcome (stated by the tagger, no quotation) | control — held | controls[1] |
| outcome (stated by the tagger, no quotation) | control — held | controls[2] |
| outcome (stated by the tagger, no quotation) | control — held | controls[3] |
| for which use | limitation — the identification of the particle, as distinct from its discovery: THESE RESULTS ARE COMPATIBLE WITH THE HYPOTHESIS THAT THE NEW PARTICLE IS THE STANDARD MODEL HIGGS BOSON, [but] MORE DATA ARE NEEDED TO ASSESS ITS NATURE IN DETAIL— “Although these results are compatible with the hypothesis that the new particle is the Standard Model Higgs boson, more data are needed to assess its nature in detail.” | limitations[0] |
| for which use | limitation — the 8 TeV WW analysis specifically: SINCE THE e-mu CHANNEL PROVIDES MOST OF THE SENSITIVITY OF THE SEARCH, ONLY THIS FINAL STATE IS USED - pile-up degraded the resolution the same-flavour states needed— “Since the eµ channel provides most of the sensitivity of the search, only this final state is used in the analysis of the 8 TeV data.” | limitations[1] |
| for which use | limitation — the 5.9 sigma figure as the discovery significance: the paper gives about 5.1 sigma globally over 110-600 GeV, and a different value again over a narrower range— “The presence of these uncertainties, evaluated as described in Ref. [138], reduces the local significance to 5.9 σ. The global significance of a local 5.9 σ excess anywhere in the mass range 110–600 GeV is estimated to be approximately 5.1 σ, increasing to 5.3” | limitations[2] |
| for which use | limitation — comparing significances across searches: the trials factor depends on the range of hypotheses considered, so the same excess yields different global significances— “The ratio of the global to the local probabilities, the trials factor used to correct for the ”look elsewhere” effect, increases with the range of Higgs boson mass hypotheses considered, the mass resolutions of the channels involved in the combination, and the significance of the excess.” | limitations[3] |
| for which use | limitation — the result as agreement with the Standard Model: the paper quantifies the compatibility at 1.5 sigma— “Theoretical uncertainties are included so that the consistency with the SM expectation can be quantified. The data are compatible with the SM expectation at the 1.5 σ level.” | limitations[4] |
| for which use | limitation — the new particle's spin: only spin-1 is disfavoured here, by the diphoton observation alone— “The observation in the diphoton channel disfavours the spin-1 hypothesis” | limitations[5] |
| replication | untested |
| limitation | The data establish a new neutral boson but are insufficient to determine whether it is in fact the Standard Model Higgs boson.— “Although these results are compatible with the hypothesis that the new particle is the Standard Model Higgs boson, more data are needed to assess its nature in detail.” | limitations[0] |
| limitation | Increased pile-up degraded missing-transverse-momentum resolution so badly that the same-flavour WW final states had to be dropped from the 8 TeV analysis.— “Since the eµ channel provides most of the sensitivity of the search, only this final state is used in the analysis of the 8 TeV data.” | limitations[1] |
| limitation | The same excess carries three significances: 5.9 sigma locally, about 5.1 sigma globally over 110-600 GeV, and 5.3 sigma over a narrower range whose bounds are lost to figure text in this staged copy.— “The presence of these uncertainties, evaluated as described in Ref. [138], reduces the local significance to 5.9 σ. The global significance of a local 5.9 σ excess anywhere in the mass range 110–600 GeV is estimated to be approximately 5.1 σ, increasing to 5.3” | limitations[2] |
| limitation | The correction from local to global significance is stated to depend on the mass range searched, the channels' mass resolutions, and the size of the excess.— “The ratio of the global to the local probabilities, the trials factor used to correct for the ”look elsewhere” effect, increases with the range of Higgs boson mass hypotheses considered, the mass resolutions of the channels involved in the combination, and the significance of the excess.” | limitations[3] |
| limitation | Compatibility with the Standard Model expectation is quantified at the 1.5 sigma level rather than asserted.— “Theoretical uncertainties are included so that the consistency with the SM expectation can be quantified. The data are compatible with the SM expectation at the 1.5 σ level.” | limitations[4] |
| limitation | Only the spin-1 hypothesis is addressed, and only by the diphoton observation.— “The observation in the diphoton channel disfavours the spin-1 hypothesis” | limitations[5] |