“CERN discovered the Higgs boson in 2012.”

Geneva, 4 July 2012. At a seminar held at CERN today as a curtain raiser to the year’s major particle physics conference, ICHEP2012 in Melbourne, the ATLAS and CMS experiments presented their latest preliminary results in the search for the long sought Higgs particle. Both experiments observe a new particle in the mass region around 125-126 GeV. … “The discovery of a particle consistent with the Higgs boson opens the way to more detailed studies, requiring larger statistics, which will pin down the new particle’s properties, and is likely to shed light on other mysteries of our universe.”## Abstract Geneva, 4 July 2012. At a seminar held at CERN today as a curtain raiser to the year’s major particle physics conference, ICHEP2012 in Melbourne, the ATLAS and CMS experiments presented their latest preliminary results in the search for the long sought Higgs particle. Both experiments observe a new particle in the mass region around 125-126 GeV. CERN physicists await the start of the Higgs seminar. “We observe in our data clear signs of a new particle, at the level of 5 sigma, in the mass region around 126 GeV. The outstanding performance of the LHC and ATLAS and the huge efforts of many people have brought us to this exciting stage,” said ATLAS experiment spokesperson Fabiola Gianotti, “but a little more time is needed to prepare these results for publication.” … The Standard Model describes the fundamental particles from which we, and every visible thing in the universe, are made, and the forces acting between them. All the matter that we can see, however, appears to be no more than about 4% of the total. A more exotic version of the Higgs particle could be a bridge to understanding the 96% of the universe that remains obscure. “We have reached a milestone in our understanding of nature,” said CERN Director General Rolf Heuer. “The discovery of a particle consistent with the Higgs boson opens the way to more detailed studies, requiring larger statistics, which will pin down the new particle’s properties, and is likely to shed light on other mysteries of our universe.” Positive identification of the new particle’s characteristics will take considerable time and data. But whatever form the Higgs particle takes, our knowledge of the fundamental structure of matter is about to take a major step forward. ## Authors

Geneva, 4 July 2012. At a seminar held at CERN today as a curtain raiser to the year’s major particle physics conference, ICHEP2012 in Melbourne, the ATLAS and CMS experiments presented their latest preliminary results in the search for the long sought Higgs particle. Both experiments observe a new particle in the mass region around 125-126 GeV. … “The discovery of a particle consistent with the Higgs boson opens the way to more detailed studies, requiring larger statistics, which will pin down the new particle’s properties, and is likely to shed light on other mysteries of our universe.”## CERN Press Release: CERN experiments observe particle consistent with long-sought Higgs boson Geneva, 4 July 2012. At a seminar held at CERN today as a curtain raiser to the year’s major particle physics conference, ICHEP2012 in Melbourne, the ATLAS and CMS experiments presented their latest preliminary results in the search for the long sought Higgs particle. Both experiments observe a new particle in the mass region around 125-126 GeV. … The Standard Model describes the fundamental particles from which we, and every visible thing in the universe, are made, and the forces acting between them. All the matter that we can see, however, appears to be no more than about 4% of the total. A more exotic version of the Higgs particle could be a bridge to understanding the 96% of the universe that remains obscure. “We have reached a milestone in our understanding of nature,” said CERN Director General Rolf Heuer. “The discovery of a particle consistent with the Higgs boson opens the way to more detailed studies, requiring larger statistics, which will pin down the new particle’s properties, and is likely to shed light on other mysteries of our universe.” Positive identification of the new particle’s characteristics will take considerable time and data. But whatever form the Higgs particle takes, our knowledge of the fundamental structure of matter is about to take a major step forward.

On July 4, 2012, CERN announced the long awaited discovery of a new fundamental particle with properties similar to those expected for the missing link of the Standard Model (SM) of particle physics, the Higgs boson.Introduction On July 4, 2012, CERN announced the long awaited discovery of a new fundamental particle with properties similar to those expected for the missing link of the Standard Model (SM) of particle physics, the Higgs boson. The discovery was made independently by two experimental collaborations – ATLAS and CMS at the Large Hadron Collider – both working with huge all purpose multichannel detectors. With significance at the level of five standard deviations, the new particle was mainly observed decaying into two channels: two photons and four leptons. This high significance implies that the probability of background fluctuations conspiring to produce the observed signal is less than 3×10-7. …

Geneva, 4 July 2012. At a seminar held at CERN today as a curtain raiser to the year’s major particle physics conference, ICHEP2012 in Melbourne, the ATLAS and CMS experiments presented their latest preliminary results in the search for the long sought Higgs particle. Both experiments observe a new particle in the mass region around 125-126 GeV. … “The discovery of a particle consistent with the Higgs boson opens the way to more detailed studies, requiring larger statistics, which will pin down the new particle’s properties, and is likely to shed light on other mysteries of our universe.”## Description Geneva, 4 July 2012. At a seminar held at CERN today as a curtain raiser to the year’s major particle physics conference, ICHEP2012 in Melbourne, the ATLAS and CMS experiments presented their latest preliminary results in the search for the long sought Higgs particle. Both experiments observe a new particle in the mass region around 125-126 GeV. CERN physicists await the start of the Higgs seminar. … The Standard Model describes the fundamental particles from which we, and every visible thing in the universe, are made, and the forces acting between them. All the matter that we can see, however, appears to be no more than about 4% of the total. A more exotic version of the Higgs particle could be a bridge to understanding the 96% of the universe that remains obscure. “We have reached a milestone in our understanding of nature,” said CERN Director General Rolf Heuer. “The discovery of a particle consistent with the Higgs boson opens the way to more detailed studies, requiring larger statistics, which will pin down the new particle’s properties, and is likely to shed light on other mysteries of our universe.” Positive identification of the new particle’s characteristics will take considerable time and data. But whatever form the Higgs particle takes, our knowledge of the fundamental structure of matter is about to take a major step forward.

Geneva, 4 July 2012. At a seminar held at CERN1 today as a curtain raiser to the year’s major particle physics conference, ICHEP2012 in Melbourne, the ATLAS and CMS experiments presented their latest preliminary results in the search for the long sought Higgs particle. Both experiments observe a new particle in the mass region around 125-126 GeV. … “We have reached a milestone in our understanding of nature,” said CERN Director General Rolf Heuer. “The discovery of a particle consistent with the Higgs boson opens the way to more detailed studies, requiring larger statistics, which will pin down the new particle’s properties, and is likely to shed light on other mysteries of our universe.”## CERN experiments observe particle consistent with long-sought Higgs boson Geneva, 4 July 2012. At a seminar held at CERN1 today as a curtain raiser to the year’s major particle physics conference, ICHEP2012 in Melbourne, the ATLAS and CMS experiments presented their latest preliminary results in the search for the long sought Higgs particle. Both experiments observe a new particle in the mass region around 125-126 GeV. “We observe in our data clear signs of a new particle, at the level of 5 sigma, in the mass region around 126 GeV. The outstanding performance of the LHC and ATLAS and the huge efforts of many people have brought us to this exciting stage,” said ATLAS experiment spokesperson Fabiola Gianotti, “but a little more time is needed to prepare these results for publication.” … Or is it something more exotic? The Standard Model describes the fundamental particles from which we, and every visible thing in the universe, are made, and the forces acting between them. All the matter that we can see, however, appears to be no more than about 4% of the total. A more exotic version of the Higgs particle could be a bridge to understanding the 96% of the universe that remains obscure. “We have reached a milestone in our understanding of nature,” said CERN Director General Rolf Heuer. “The discovery of a particle consistent with the Higgs boson opens the way to more detailed studies, requiring larger statistics, which will pin down the new particle’s properties, and is likely to shed light on other mysteries of our universe.” Positive identification of the new particle’s characteristics will take considerable time and data. But whatever form the Higgs particle takes, our knowledge of the fundamental structure of matter is about to take a major step forward.

On 4 July 2012, the ATLAS and CMS experiments at CERN announced that they had independently observed a new particle in the mass region of around 125 GeV: a particle consistent with the Higgs boson.… To solve this problem, three teams of theorists: Robert Brout and François Englert; Peter Higgs; Gerald Guralnik, Carl Hagen, and Tom Kibble independently proposed a solution now referred to as the Brout-Englert-Higgs (BEH) mechanism. The BEH mechanism requires the presence of a new field throughout the universe which gives mass to some of the bosons. Existence of this field could be verified by discovery of its associated particle – the Higgs boson. On 4 July 2012, the ATLAS and CMS experiments at CERN announced that they had independently observed a new particle in the mass region of around 125 GeV: a particle consistent with the Higgs boson. On 8 October 2013, the Nobel Prize in Physics was awarded jointly to theorists François Englert and Peter Higgs "for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN's Large Hadron Collider".

The Higgs boson was discovered, almost 50 years after first being proposed, by the ATLAS and CMS collaborations at CERN in 2012.## How did we discover the Higgs boson? The Higgs boson was discovered, almost 50 years after first being proposed, by the ATLAS and CMS collaborations at CERN in 2012. But why did it take so long to find it? With a mass of more than 120 times that of the proton, the Higgs boson is the second-heaviest particle known today. This large mass, combined with an extremely short lifetime (10 -22 seconds) means that the particle cannot be found in Nature – its existence can only be verified by producing it in the lab.

CMS Experiment, CERN 4 July 2012 … In a joint seminar today at CERN and the “ICHEP 2012” conference [1] in Melbourne, researchers of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) presented their preliminary results on the search for the standard model (SM) Higgs boson in their data recorded up to June 2012. … We interpret this to be due to the production of a previously unobserved particle with a mass of around 125 GeV.CMS Experiment, CERN 4 July 2012 … ##### Summary In a joint seminar today at CERN and the “ICHEP 2012” conference [1] in Melbourne, researchers of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) presented their preliminary results on the search for the standard model (SM) Higgs boson in their data recorded up to June 2012. CMS observes an excess of events at a mass of approximately 125 GeV [2] with a statistical significance of five standard deviations (5 sigma) [3] above background expectations. The probability of the background alone fluctuating up by this amount or more is about one in three million. The evidence is strongest in the two final states with the best mass resolution: first the two-photon final state and second the final state with two pairs of charged leptons (electrons or muons). We interpret this to be due to the production of a previously unobserved particle with a mass of around 125 GeV. The CMS data also rule out the existence of the SM Higgs boson in the ranges 110–122.5 GeV and 127–600 GeV with 95% confidence level [4] – lower masses were already excluded by CERN’s LEP collider at the same confidence level. …

On 4 July, 2012, the ATLAS experiment presented a preview of its updated results on the search for the Higgs Boson. … "We observe in our data clear signs of a new particle, at the level of 5 sigma, in the mass region around 126 GeV. … In the weeks and months ahead, ATLAS will better measure these properties, enabling a clearer picture to emerge about whether this particle is the Higgs Boson, or the first of a larger family of such particles, or something else entirely.Candidate Higgs decay to four electrons recorded by ATLAS in 2012. On 4 July, 2012, the ATLAS experiment presented a preview of its updated results on the search for the Higgs Boson. The results were shown at a seminar held jointly at CERN and via video link at ICHEP, the International Conference for High Energy Physics in Melbourne, Australia, where detailed analyses will be presented later this week. … The solid line traces a statistical fit to the signal plus background. The new particle appears as the excess around 126.5 GeV. The full analysis concludes that the probability of such a peak is three chances in a million. "The search is more advanced today than we imagined possible," said ATLAS spokesperson Fabiola Gianotti. "We observe in our data clear signs of a new particle, at the level of 5 sigma, in the mass region around 126 GeV. The outstanding performance of the LHC and ATLAS and the huge efforts of many people have brought us to this exciting stage. A little more time is needed to finalize these results, and more data and more study will be needed to determine the new particle’s properties." … Already some of these properties match the predictions: the fact that it is seen in the predicted channels and at a mass favoured by other, indirect measurements. In the weeks and months ahead, ATLAS will better measure these properties, enabling a clearer picture to emerge about whether this particle is the Higgs Boson, or the first of a larger family of such particles, or something else entirely. Experimental limits from ATLAS on Standard Model Higgs production in the mass range 110-600 GeV. The solid curve reflects the observed experimental limits for the production of a Higgs of each possible mass value (horizontal axis). …

Clear evidence for the production of a neutral boson with a measured mass of 126.0± 0.4 (stat)± 0.4 (sys) GeV is presented. This observation, which has a significance of 5.9 standard deviations, corresponding to a background fluctuation probability of 1.7× 10− 9, is compatible with the production and decay of the Standard Model Higgs boson. … These results provide conclusive evidence for the discovery of a new particle with mass 126.0 ± 0.4 (stat) ± 0.4 (sys) GeV.… The datasets used correspond to integrated luminosities of approximately 4.8 fb− 1 collected at √s = 7 TeV in 2011 and 5.8 fb− 1 at √s = 8 TeV in 2012. Individual searches in the channels H → Z Z (∗ ) → 4 , H → γγ and H → W W (∗ ) → eνμν in the 8 TeV data are combined with previously published results of searches for H → Z Z (∗ ), W W (∗ ), b¯b and τ +τ − in the 7 TeV data and results from improved analyses of the H → Z Z (∗ ) → 4 and H → γγ channels in the 7 TeV data. Clear evidence for the production of a neutral boson with a measured mass of 126.0± 0.4 (stat)± 0.4 (sys) GeV is presented. This observation, which has a significance of 5.9 standard deviations, corresponding to a background fluctuation probability of 1.7× 10− 9, is compatible with the production and decay of the Standard Model Higgs boson. © 2012 CERN. Published by Elsevier B.V. All rights reserved. … In this region, an excess of events with significance 5.9σ , corresponding to p0 = 1.7 × 10− 9, is observed. The excess is driven by the two channels with the highest mass resolution, H → Z Z (∗ ) → 4 and H → γγ , and the equally sensitive but low resolution H → W W (∗ ) → ν ν channel. Taking into account the entire mass range of the search, 110–600 GeV, the global signifi cance of the excess is 5.1σ , which corresponds to p0 = 1.7× 10− 7. These results provide conclusive evidence for the discovery of a new particle with mass 126.0 ± 0.4 (stat) ± 0.4 (sys) GeV. The sig nal strength parameter μ has the value 1.4± 0.3 at the fitted mass, which is consistent with the SM Higgs boson hypothesis μ = 1. The decays to pairs of vector bosons whose net electric charge is zero identify the new particle as a neutral boson. The observa tion in the diphoton channel disfavours the spin-1 hypothesis [140, 141]. …

Observation of a new boson with a mass near 125 GeV The CMS Collaboration Abstract Combined results are presented from searches for the standard model (SM) Higgs boson in proton-proton collisions at √ s = 7 and 8 TeV in five decay modes: γγ, bb, ττ, WW, and ZZ.Available on the CERN CDS information server CMS PAS HIG-12-020 CMS Physics Analysis Summary Contact: cms-pag-conveners-higgs@cern.ch 2012/07/09 Observation of a new boson with a mass near 125 GeV The CMS Collaboration Abstract Combined results are presented from searches for the standard model (SM) Higgs boson in proton-proton collisions at √ s = 7 and 8 TeV in five decay modes: γγ, bb, ττ, WW, and ZZ. The analysed data correspond to integrated luminosities of up to 5.1 fb−1 at 7 TeV and 5.3 fb−1 at 8 TeV. The data exclude the existence of a SM Higgs boson in the ranges 110–122.5 and 127–600 GeV at 95% confidence level. An excess of events above the expected SM background is observed with a local significance of 4.9σ around 125 GeV, which we attribute to the production of a previously unobserved particle. The evidence is strongest in the two final states with the best mass …

These results provide conclusive evidence for the discovery of a new particle with mass 126.0 ± 0.4 (stat) ± 0.4 (sys) GeV. The signal strength parameter µ has the value 1.4 ± 0.3 at the fitted mass, which is consistent with the SM Higgs boson hypothesis µ = 1.Figure 12: Likelihood contours for the H→ γγ channel in the (µggF+ttH¯ , µVBF+VH) plane including the branching ratio factor B/BSM. The quantity µggF+ttH¯ (µVBF+VH) is a common scale factor for the ggF and ttH¯ (VBF and VH) production cross sections. The best fit to the data (+) and 68% (full) and 95% (dashed) CL contours are also indicated, as well as the SM expectation (× ). These results provide conclusive evidence for the discovery of a new particle with mass 126.0 ± 0.4 (stat) ± 0.4 (sys) GeV. The signal strength parameter µ has the value 1.4 ± 0.3 at the fitted mass, which is consistent with the SM Higgs boson hypothesis µ = 1. The decays to pairs of vector bosons whose net electric charge is zero identify the new particle as a neutral boson. The observation in the diphoton channel disfavours the spin-1 hypothe sis [140, 141]. 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. Acknowledgements

Results are presented from searches for the standard model Higgs boson in proton–proton collisions at s=7 and 8 TeV in the Compact Muon Solenoid experiment at the LHC, using data samples corresponding to integrated luminosities of up to 5.1 fb−1 at 7 TeV and 5.3 fb−1 at 8 TeV. … An excess of events is observed above the expected background, with a local significance of 5.0 standard deviations, at a mass near 125 GeV, signalling the production of a new particle.## Abstract Results are presented from searches for the standard model Higgs boson in proton–proton collisions at s=7 and 8 TeV in the Compact Muon Solenoid experiment at the LHC, using data samples corresponding to integrated luminosities of up to 5.1 fb−1 at 7 TeV and 5.3 fb−1 at 8 TeV. The search is performed in five decay modes: γγ, ZZ, W+W−, τ+τ−, and bb¯. An excess of events is observed above the expected background, with a local significance of 5.0 standard deviations, at a mass near 125 GeV, signalling the production of a new particle. The expected significance for a standard model Higgs boson of that mass is 5.8 standard deviations. The excess is most significant in the two decay modes with the best mass resolution, γγ and ZZ; a fit to these signals gives a mass of 125.3±0.4(stat.)±0.5(syst.) GeV. The decay to two photons indicates that the new particle is a boson with spin different from one. - Previousarticle in issue - Nextarticle in issue

A significant 5σ excess of events is observed in the search for the Standard Model Higgs boson, dominated by the two channels with the highest mass resolutions. This observation provides evidence for a new, narrow resonance at a mass near 126.5 GeV.→ ` +`−` +`− analyses. The observed SM Higgs boson exclusion ranges at the 95% CL are 110 GeV to 122.6 GeV and 129.7 GeV to 558 GeV, while masses between 110 GeV to 582 GeV are expected to be excluded at the 95% CL. A significant 5σ excess of events is observed in the search for the Standard Model Higgs boson, dominated by the two channels with the highest mass resolutions. This observation provides evidence for a new, narrow resonance at a mass near 126.5 GeV. Although the combined result including all search channels is consistent with the production and decay of a Standard Model Higgs boson, more data are needed to assess the nature of this excess. [GeV] mH

The CMS Collaboration has observed, with a statistical significance of five standard deviations, a new particle produced in proton-proton collisions at the Large Hadron Collider at CERN. … Although its measured properties are, within the uncertainties of the present data, consistent with those expected of the Higgs boson, more data are needed to elucidate the precise nature of the new particle.## Abstract The Higgs boson was postulated nearly five decades ago within the framework of the standard model of particle physics and has been the subject of numerous searches at accelerators around the world. Its discovery would verify the existence of a complex scalar field thought to give mass to three of the carriers of the electroweak force—the W+, W–, and Z0 bosons—as well as to the fundamental quarks and leptons. The CMS Collaboration has observed, with a statistical significance of five standard deviations, a new particle produced in proton-proton collisions at the Large Hadron Collider at CERN. The evidence is strongest in the diphoton and four-lepton (electrons and/or muons) final states, which provide the best mass resolution in the CMS detector. The probability of the observed signal being due to a random fluctuation of the background is about 1 in 3 × 106. The new particle is a boson with spin not equal to 1 and has a mass of about 125 giga–electron volts. Although its measured properties are, within the uncertainties of the present data, consistent with those expected of the Higgs boson, more data are needed to elucidate the precise nature of the new particle. ## Access the full article

The Nobel Prize in Physics 2013 was awarded jointly to François Englert and Peter W. Higgs "for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN's Large Hadron Collider"© Nobel Prize Outreach. Photo: A. Mahmoud > The Nobel Prize in Physics 2013 was awarded jointly to François Englert and Peter W. Higgs "for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN's Large Hadron Collider"

On 4 July 2012, as a curtain raiser to the year’s major particle physics conference, ICHEP 2012 in Melbourne, the ATLAS and CMS experiments present their latest preliminary results in the search for the long-sought Higgs particle. … Both experiments have observed a new particle in the mass region around 125-126 GeV.ATLAS spokesperson, Fabiola Gianotti, presents the collaboration's results. (IMAGE: CERN) On 4 July 2012, as a curtain raiser to the year’s major particle physics conference, ICHEP 2012 in Melbourne, the ATLAS and CMS experiments present their latest preliminary results in the search for the long-sought Higgs particle. Both experiments have observed a new particle in the mass region around 125-126 GeV. The next step is to determine the precise nature of the particle and its significance for our understanding of the universe. Are its properties as expected for the long-sought Higgs boson, the final missing ingredient in the Standard Model of particle physics? Or is it something more exotic? The Standard Model describes the fundamental particles from which we, and every visible thing in the universe, are made, and the forces acting between them. …

An excess of events is observed above the expected background, with a local significance of 5.0 standard deviations, at a mass near 125 GeV, signalling the production of a new particle. … The excess is most significant in the two decay modes with the best mass resolution, γγ and ZZ; a fit to these signals gives a mass of 125.3 ± 0.4(stat.) ± 0.5(syst.) GeV. … The decay to two photons indicates that the new particle is a boson with spin different from one.… Accepted 11 August 2012 Available online 18 August 2012 Editor: W.-D. Schlatter Keywords: CMS Physics Higgs Results are presented from searches for the standard model Higgs boson in proton–proton collisions at √s = 7 and 8 TeV in the Compact Muon Solenoid experiment at the LHC, using data samples corresponding to integrated luminosities of up to 5.1 fb− 1 at 7 TeV and 5.3 fb− 1 at 8 TeV. The search is performed in five decay modes: γγ , ZZ, W+W−, τ +τ −, and bb. An excess of events is observed above the expected background, with a local significance of 5.0 standard deviations, at a mass near 125 GeV, signalling the production of a new particle. The expected significance for a standard model Higgs boson of that mass is 5.8 standard deviations. The excess is most significant in the two decay modes with the best mass resolution, γγ and ZZ; a fit to these signals gives a mass of 125.3 ± 0.4(stat.) ± 0.5(syst.) GeV. The decay to two photons indicates that the new particle is a boson with spin different from one. © 2012 CERN. Published by Elsevier B.V. All rights reserved. #### 1. Introduction

These results provide conclusive evidence for the discovery of a new particle with mass 126.0 ± 0.4 (stat) ± 0.4 (sys) GeV. … 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.… In this region, an excess of events with significance 5.9σ , corresponding to p0 = 1.7 × 10− 9, is observed. The excess is driven by the two channels with the highest mass resolution, H → Z Z (∗ ) → 4 and H → γγ , and the equally sensitive but low resolution H → W W (∗ ) → ν ν channel. Taking into account the entire mass range of the search, 110–600 GeV, the global signifi cance of the excess is 5.1σ , which corresponds to p0 = 1.7× 10− 7. These results provide conclusive evidence for the discovery of a new particle with mass 126.0 ± 0.4 (stat) ± 0.4 (sys) GeV. The sig nal strength parameter μ has the value 1.4± 0.3 at the fitted mass, which is consistent with the SM Higgs boson hypothesis μ = 1. The decays to pairs of vector bosons whose net electric charge is zero identify the new particle as a neutral boson. The observa tion in the diphoton channel disfavours the spin-1 hypothesis [140, 141]. 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. #### Acknowledgements

These results provide conclusive evidence for the discovery of a new particle with mass 126.0 ± 0.4 (stat) ± 0.4 (sys) GeV.… In this region, an excess of events with significance 5.9σ , corresponding to p0 = 1.7 × 10− 9, is observed. The excess is driven by the two channels with the highest mass resolution, H → Z Z (∗ ) → 4 and H → γγ , and the equally sensitive but low resolution H → W W (∗ ) → ν ν channel. Taking into account the entire mass range of the search, 110–600 GeV, the global signifi cance of the excess is 5.1σ , which corresponds to p0 = 1.7× 10− 7. These results provide conclusive evidence for the discovery of a new particle with mass 126.0 ± 0.4 (stat) ± 0.4 (sys) GeV. The sig nal strength parameter μ has the value 1.4± 0.3 at the fitted mass, which is consistent with the SM Higgs boson hypothesis μ = 1. The decays to pairs of vector bosons whose net electric charge is zero identify the new particle as a neutral boson. The observa tion in the diphoton channel disfavours the spin-1 hypothesis [140, 141]. …

Clear evidence for the production of a neutral boson with a measured mass of 126.0 +/- 0.4(stat) +/- 0.4(sys) GeV is presented. This observation, which has a significance of 5.9 standard deviations, corresponding to a background fluctuation probability of 1.7x10^-9, is compatible with the production and decay of the Standard Model Higgs boson.… The datasets used correspond to integrated luminosities of approximately 4.8 fb^-1 collected at sqrt(s) = 7 TeV in 2011 and 5.8 fb^-1 at sqrt(s) = 8 TeV in 2012. Individual searches in the channels H->ZZ^(*)->llll, H->gamma gamma and H->WW->e nu mu nu in the 8 TeV data are combined with previously published results of searches for H->ZZ^(*), WW^(*), bbbar and tau^+tau^- in the 7 TeV data and results from improved analyses of the H->ZZ^(*)->llll and H->gamma gamma channels in the 7 TeV data. Clear evidence for the production of a neutral boson with a measured mass of 126.0 +/- 0.4(stat) +/- 0.4(sys) GeV is presented. This observation, which has a significance of 5.9 standard deviations, corresponding to a background fluctuation probability of 1.7x10^-9, is compatible with the production and decay of the Standard Model Higgs boson. | Comments: | 24 pages plus author list (38 pages total), 12 figures, 7 tables, revised author list, matches version to appear in Physics Letters B | | --- | --- | | Subjects: | High Energy Physics - Experiment (hep-ex) | | Journal reference: | Phys.Lett. B716 (2012) 1-29 | | DOI: | 10.1016/j.physletb.2012.08.020 | | Report number: | CERN-PH-EP-2012-218 | | Cite as: | arXiv:1207.7214 [hep-ex] | | | (or arXiv:1207.7214v2 [hep-ex] for this version) |

Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHCObservation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC (Journal Article) | OSTI.GOV Skip to main content

Clear evidence for the production of a neutral boson with a measured mass of 126.0± 0.4 (stat)± 0.4 (sys) GeV is presented. This observation, which has a significance of 5.9 standard deviations, corresponding to a background fluctuation probability of 1.7× 10− 9, is compatible with the production and decay of the Standard Model Higgs boson. … These results provide conclusive evidence for the discovery of a new particle with mass 126.0 ± 0.4 (stat) ± 0.4 (sys) GeV.… The datasets used correspond to integrated luminosities of approximately 4.8 fb− 1 collected at √s = 7 TeV in 2011 and 5.8 fb− 1 at √s = 8 TeV in 2012. Individual searches in the channels H → Z Z (∗ ) → 4 , H → γγ and H → W W (∗ ) → eνμν in the 8 TeV data are combined with previously published results of searches for H → Z Z (∗ ), W W (∗ ), b¯b and τ +τ − in the 7 TeV data and results from improved analyses of the H → Z Z (∗ ) → 4 and H → γγ channels in the 7 TeV data. Clear evidence for the production of a neutral boson with a measured mass of 126.0± 0.4 (stat)± 0.4 (sys) GeV is presented. This observation, which has a significance of 5.9 standard deviations, corresponding to a background fluctuation probability of 1.7× 10− 9, is compatible with the production and decay of the Standard Model Higgs boson. © 2012 CERN. Published by Elsevier B.V. All rights reserved. … In this region, an excess of events with significance 5.9σ , corresponding to p0 = 1.7 × 10− 9, is observed. The excess is driven by the two channels with the highest mass resolution, H → Z Z (∗ ) → 4 and H → γγ , and the equally sensitive but low resolution H → W W (∗ ) → ν ν channel. Taking into account the entire mass range of the search, 110–600 GeV, the global signifi cance of the excess is 5.1σ , which corresponds to p0 = 1.7× 10− 7. These results provide conclusive evidence for the discovery of a new particle with mass 126.0 ± 0.4 (stat) ± 0.4 (sys) GeV. The sig nal strength parameter μ has the value 1.4± 0.3 at the fitted mass, which is consistent with the SM Higgs boson hypothesis μ = 1. The decays to pairs of vector bosons whose net electric charge is zero identify the new particle as a neutral boson. The observa tion in the diphoton channel disfavours the spin-1 hypothesis [140, 141]. …

As was pointed out by Higgs, a key prediction of the idea is the existence of a massive boson of a new type, which was discovered by the ATLAS and CMS experiments at CERN in 2012.… It explains how the force responsible for beta decay is much weaker than electromagnetism, but is better known as the mechanism that endows fundamental particles with mass. A third paper, published by Americans Gerald Guralnik and Carl Hagen with their British colleague Tom Kibble further contributed to the development of the new idea, which now forms an essential part of the Standard Model of particle physics. As was pointed out by Higgs, a key prediction of the idea is the existence of a massive boson of a new type, which was discovered by the ATLAS and CMS experiments at CERN in 2012. Timeline

In June 2012, the ATLAS and CMS collaborations at CERN announced, that they had discovered a particle with the right properties to be the Higgs boson, which signified that researchers had confirmed a fundamental theory of mass.Panos Charitos 20th Sep 2022 The Higgs boson is the final piece of the standard model of particle physics to be observed, following decades of research. In June 2012, the ATLAS and CMS collaborations at CERN announced, that they had discovered a particle with the right properties to be the Higgs boson, which signified that researchers had confirmed a fundamental theory of mass. The following 10 years have seen impressive advances in our understanding of the Higgs boson's properties. The experimental collaborations, not only test whether the properties of the Higgs boson agree with those predicted by the Standard Model but also looking for properties that would provide evidence for new physics. ore data from the LHC could shed light to some of the remaining open questions.

In July 2012, The European Organization for Nuclear Research(CERN) in Geneva announced they had captured a new particle that may be the elusive Higgs boson in two gigantic experiments, ATLAS and CMS, both of which independently confirmed the particle’s existence.… The papers: “ Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC” and “ Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC” are freely available online on ScienceDirect. In July 2012, The European Organization for Nuclear Research(CERN) in Geneva announced they had captured a new particle that may be the elusive Higgs boson in two gigantic experiments, ATLAS and CMS, both of which independently confirmed the particle’s existence. A world-wide collaboration of more than 5,000 researchers contributed to the discovery. "These papers present the first observations of a new particle discovered by two big experiments at the Large Hadron Collider (LHC) in the search for the Standard Model Higgs boson which has spanned many decades and has involved many experiments,” explains physicist Joe Incandela, spokesperson of the CMS experiment. …

The existence of this mass-giving field was confirmed in 2012, when the Higgs boson particle was discovered at CERN.# The Higgs boson You and everything around you are made of particles. But when the universe began, no particles had mass; they all sped around at the speed of light. Stars, planets and life could only emerge because particles gained their mass from a fundamental field associated with the Higgs boson. The existence of this mass-giving field was confirmed in 2012, when the Higgs boson particle was discovered at CERN. ## What is the Higgs boson?

On 4 July, the ATLAS and CMS collaborations announce the discovery of a particle with features consistent with those of the Higgs boson, a particle predicted almost 50 years earlier.A round of applause for Fabiola Gianotti (left), ATLAS spokesperson, and Joe Incandela, CMS spokesperson, and for the LHC project leader Lyn Evans (waving), at the announcement of the discovery of the Higgs boson. On 4 July, the ATLAS and CMS collaborations announce the discovery of a particle with features consistent with those of the Higgs boson, a particle predicted almost 50 years earlier. This particle is a manifestation of the Higgs field, which gives mass to elementary particles. The following March, after examining two and a half times more data, ATLAS and CMS conclude that some kind of Higgs boson has indeed been discovered. 2010

Geneva, 4 July 2012. At a seminar held at CERN 1 today as a curtain raiser to the year’s major particle physics conference, ICHEP2012 in Melbourne, the ATLAS and CMS experiments presented their latest preliminary results in the search for the long sought Higgs particle. Both experiments observe a new particle in the mass region around 125-126 GeV. … “We observe in our data clear signs of a new particle, at the level of 5 sigma, in the mass region around 126 GeV. The outstanding performance of the LHC and ATLAS and the huge efforts of many people have brought us to this exciting stage,” said ATLAS experiment spokesperson Fabiola Gianotti, “but a little more time is needed to prepare these results for publication.” … The results presented today are labelled preliminary. They are based on data collected in 2011 and 2012, with the 2012 data still under analysis.04 July, 2012 Geneva, 4 July 2012. At a seminar held at CERN 1 today as a curtain raiser to the year’s major particle physics conference, ICHEP2012 in Melbourne, the ATLAS and CMS experiments presented their latest preliminary results in the search for the long sought Higgs particle. Both experiments observe a new particle in the mass region around 125-126 GeV. “We observe in our data clear signs of a new particle, at the level of 5 sigma, in the mass region around 126 GeV. The outstanding performance of the LHC and ATLAS and the huge efforts of many people have brought us to this exciting stage,” said ATLAS experiment spokesperson Fabiola Gianotti, “but a little more time is needed to prepare these results for publication.” “The results are preliminary but the 5 sigma signal at around 125 GeV we’re seeing is dramatic. This is indeed a new particle. We know it must be a boson and it’s the heaviest boson ever found,” said CMS experiment spokesperson Joe Incandela. “The implications are very significant and it is precisely for this reason that we must be extremely diligent in all of our studies and cross-checks.” “It’s hard not to get excited by these results,” said CERN Research Director Sergio Bertolucci. “ We stated last year that in 2012 we would either find a new Higgs-like particle or exclude the existence of the Standard Model Higgs. With all the necessary caution, it looks to me that we are at a branching point: the observation of this new particle indicates the path for the future towards a more detailed understanding of what we’re seeing in the data.” The results presented today are labelled preliminary. They are based on data collected in 2011 and 2012, with the 2012 data still under analysis. Publication of the analyses shown today is expected around the end of July. A more complete picture of today’s observations will emerge later this year after the LHC provides the experiments with more data. The next step will be to determine the precise nature of the particle and its significance for our understanding of the universe. Are its properties as expected for the long-sought Higgs boson, the final missing ingredient in the Standard Model of particle physics? …

Confirming the electroweak Standard Model drove three major projects at CERN spanning three decades, culminating in the discovery of the Higgs boson on 4 July 2012.1 July 2022 Confirming the electroweak Standard Model drove three major projects at CERN spanning three decades, culminating in the discovery of the Higgs boson on 4 July 2012. Matthew Chalmers captures a glimpse of particle physics’ great adventure. Historic ATLAS and CMS spokespersons Fabiola Gianotti and Joe Incandela commanding a global audience during their 4 July 2012 presentations. Credit: CERN-HI-1207136-58

At a seminar held at CERN today (July 4) as a curtain raiser to the year's major particle physics conference, ICHEP2012 in Melbourne, the ATLAS and CMS experiments presented their latest preliminary results in the search for the long sought Higgs particle. … "The discovery of a particle consistent with the Higgs boson opens the way to more detailed studies, requiring larger statistics, which will pin down the new particle's properties, and is likely to shed light on other mysteries of our universe."FULL STORY At a seminar held at CERN today (July 4) as a curtain raiser to the year's major particle physics conference, ICHEP2012 in Melbourne, the ATLAS and CMS experiments presented their latest preliminary results in the search for the long sought Higgs particle. Both experiments observe a new particle in the mass region around 125-126 GeV. "We observe in our data clear signs of a new particle, at the level of 5 sigma, in the mass region around 126 GeV. The outstanding performance of the LHC and ATLAS and the huge efforts of many people have brought us to this exciting stage," said ATLAS experiment spokesperson Fabiola Gianotti, "but a little more time is needed to prepare these results for publication." … The Standard Model describes the fundamental particles from which we, and every visible thing in the universe, are made, and the forces acting between them. All the matter that we can see, however, appears to be no more than about 4% of the total. A more exotic version of the Higgs particle could be a bridge to understanding the 96% of the universe that remains obscure. "We have reached a milestone in our understanding of nature," said CERN Director General Rolf Heuer. "The discovery of a particle consistent with the Higgs boson opens the way to more detailed studies, requiring larger statistics, which will pin down the new particle's properties, and is likely to shed light on other mysteries of our universe." Positive identification of the new particle's characteristics will take considerable time and data. But whatever form the Higgs particle takes, our knowledge of the fundamental structure of matter is about to take a major step forward.

After a 40-year search, a subatomic particle with the expected properties was discovered in 2012 by the ATLAS and CMS experiments at the Large Hadron Collider (LHC) at CERN near Geneva, Switzerland.… All fundamental particles known at the time [c] should be massless at very high energies, but fully explaining how some particles gain mass at lower energies had been extremely difficult. If these ideas were correct, a particle known as a scalar boson (with certain properties) should also exist. This particle was called the Higgs boson and could be used to test whether the Higgs field was the correct explanation. After a 40-year search, a subatomic particle with the expected properties was discovered in 2012 by the ATLAS and CMS experiments at the Large Hadron Collider (LHC) at CERN near Geneva, Switzerland. The new particle was subsequently confirmed to match the expected properties of a Higgs boson. Physicists from two of the three teams, Peter Higgs and François Englert, were awarded the Nobel Prize in Physics in 2013 for their theoretical predictions. Although Higgs's name has come to be associated with this theory, several researchers between about 1960 and 1972 independently developed different parts of it.

These results provide conclusive evidence for the discovery of a new particle with mass 126.0 ± 0.4 (stat) ± 0.4 (sys) GeV. … 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.… In this region, an excess of events with significance 5.9σ , corresponding to p0 = 1.7 × 10− 9, is observed. The excess is driven by the two channels with the highest mass resolution, H → Z Z (∗ ) → 4 and H → γγ , and the equally sensitive but low resolution H → W W (∗ ) → ν ν channel. Taking into account the entire mass range of the search, 110–600 GeV, the global signifi cance of the excess is 5.1σ , which corresponds to p0 = 1.7× 10− 7. These results provide conclusive evidence for the discovery of a new particle with mass 126.0 ± 0.4 (stat) ± 0.4 (sys) GeV. The sig nal strength parameter μ has the value 1.4± 0.3 at the fitted mass, which is consistent with the SM Higgs boson hypothesis μ = 1. The decays to pairs of vector bosons whose net electric charge is zero identify the new particle as a neutral boson. The observa tion in the diphoton channel disfavours the spin-1 hypothesis [140, 141]. 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. #### Acknowledgements