The search for the Higgs boson https://timeline.web.cern.ch/taxonomy/term/87 en ATLAS and CMS observe a particle consistent with the Higgs boson https://timeline.web.cern.ch/atlas-and-cms-observe-particle-consistent-higgs-boson <div data-history-node-id="520" class="node node--type-timeline-entry node--view-mode-rss ds-1col clearfix"> <div class="field field--name-field-date-historical-2 field--type-datetime field--label-hidden field--item">04 07, 2012</div> <div class="field field--name-field-drupal-7-path field--type-string field--label-above"> <div class="field--label">Drupal 7 path</div> <div class="field--item">atlas-and-cms-observe-a-particle-consistent-with-the-higgs-boson</div> </div> <div class="field field--name-field-image field--type-image field--label-hidden field--item"> <img src="/sites/timeline.web.cern.ch/files/Higgs-Gianotti.jpg" width="640" height="427" alt="" typeof="foaf:Image" class="img-responsive" /> </div> <div class="field field--name-field-caption field--type-text-long field--label-hidden field--item"><p>ATLAS spokesperson, Fabiola Gianotti, presents the collaboration's results. (IMAGE: CERN)</p></div> <div class="field field--name-body field--type-text-with-summary field--label-hidden field--item"><p><iframe allowfullscreen="" frameborder="0" height="315" scrolling="no" src="https://videos.cern.ch/video/CERN-VIDEO-2012-110-001" width="560"></iframe></p> <p>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. </p> <p>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. 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.</p> <p>Explore the <a href="http://indico.cern.ch/event/196564/">resources prepared for press</a>.</p> </div> <div class="field field--name-field-timeline field--type-entity-reference field--label-inline"> <div class="field--label">Timeline</div> <div class="field--items"> <div class="field--item"><a href="/taxonomy/term/143" hreflang="en">The ATLAS experiment</a></div> <div class="field--item"><a href="/taxonomy/term/93" hreflang="en">The Large Hadron Collider</a></div> <div class="field--item"><a href="/taxonomy/term/89" hreflang="en">The history of CERN</a></div> <div class="field--item"><a href="/taxonomy/term/87" hreflang="en">The search for the Higgs boson</a></div> <div class="field--item"><a href="/taxonomy/term/147" hreflang="en">Archive of important events in CERN&#039;s history for press</a></div> </div> </div> <div class="field field--name-field-media-type field--type-list-string field--label-above"> <div class="field--label">Media type</div> <div class="field--item">CDS Media</div> </div> </div> Wed, 13 Jun 2018 16:00:18 +0000 everisdrupal 520 at https://timeline.web.cern.ch Higgs boson ATLAS and CMS submit Higgs-search papers https://timeline.web.cern.ch/atlas-and-cms-submit-higgs-search-papers <div data-history-node-id="430" class="node node--type-timeline-entry node--view-mode-rss ds-1col clearfix"> <div class="field field--name-field-date-historical-2 field--type-datetime field--label-hidden field--item">01 08, 2012</div> <div class="field field--name-field-drupal-7-path field--type-string field--label-above"> <div class="field--label">Drupal 7 path</div> <div class="field--item">atlas-and-cms-submit-higgs-search-papers</div> </div> <div class="field field--name-body field--type-text-with-summary field--label-hidden field--item"><p>The ATLAS and CMS collaborations submitted papers to the journal <em>Physics Letters B</em> outlining the latest on their searches for the Higgs boson. The teams reported even stronger evidence for the presence of a new Higgs-like particle than they announced the month before.</p> <p>On 4 July the experiments reported indications for the presence of a new particle, which could be the Higgs boson, in the mass region around 126 gigaelectronvolts (GeV). Both ATLAS and CMS gave the level of significance of the result as 5 sigma. On the scale that particle physicists use to describe the certainty of a discovery, one sigma means the results could be random fluctuations in the data, 3 sigma counts as evidence and a 5-sigma result is a discovery.</p> <p>The CMS results reported today reach a significance of 5.0 sigma, and the ATLAS team's results reach 5.9 sigma. The value corresponds to a one-in-550 million chance that in the absence of a Higgs such a signal would be recorded.</p> <h3> Find out more</h3> <ul><li> <a href="http://arxiv.org/abs/1207.7214">ATLAS paper</a></li> <li> <a href="http://arxiv.org/abs/1207.7235">CMS paper</a></li> <li> <a href="http://press.web.cern.ch/press/background/B01-Higgs_en.html">About the Higgs boson</a></li> <li> <a href="http://cdsweb.cern.ch/record/1458922">Video: What is the Higgs boson?</a></li> <li> <a href="http://www.symmetrymagazine.org/breaking/2012/08/01/physicists-show-strengthened-signals-of-higgs-like-particle-in-publications/">Symmetry<em>breaking</em>: Physicists show strengthened signals of Higgs-like particle</a></li> </ul></div> <div class="field field--name-field-timeline field--type-entity-reference field--label-inline"> <div class="field--label">Timeline</div> <div class="field--items"> <div class="field--item"><a href="/taxonomy/term/87" hreflang="en">The search for the Higgs boson</a></div> </div> </div> </div> Wed, 13 Jun 2018 15:59:49 +0000 everisdrupal 430 at https://timeline.web.cern.ch Higgs boson ATLAS CMS Higgs, Brout and Englert independently work out the Higgs mechanism https://timeline.web.cern.ch/higgs-brout-and-englert-independently-work-out-higgs-mechanism <div data-history-node-id="393" class="node node--type-timeline-entry node--view-mode-rss ds-1col clearfix"> <div class="field field--name-field-date-historical-2 field--type-datetime field--label-hidden field--item">19 10, 1964</div> <div class="field field--name-field-drupal-7-path field--type-string field--label-above"> <div class="field--label">Drupal 7 path</div> <div class="field--item">events/higgs-brout-and-englert-independently-work-out-the-higgs-mechanism</div> </div> <div class="field field--name-body field--type-text-with-summary field--label-hidden field--item"><p>British physicist Peter Higgs, and independently Robert Brout and Francois Englert publish papers describing a mechanism which explains how particles could get mass. Higgs calls the hypothetical particle the "Higgs boson" in his paper <em>Broken Symmetries and the Masses of Gauge Bosons</em>, published on 19 October 1964 in the journal <em>Physical Review Letters.</em></p> </div> <div class="field field--name-field-timeline field--type-entity-reference field--label-inline"> <div class="field--label">Timeline</div> <div class="field--items"> <div class="field--item"><a href="/taxonomy/term/87" hreflang="en">The search for the Higgs boson</a></div> </div> </div> </div> Wed, 13 Jun 2018 15:59:41 +0000 everisdrupal 393 at https://timeline.web.cern.ch Higgs boson Large Electron-Positron collider: First injection https://timeline.web.cern.ch/large-electron-positron-collider-first-injection <div data-history-node-id="390" class="node node--type-timeline-entry node--view-mode-rss ds-1col clearfix"> <div class="field field--name-field-date-historical-2 field--type-datetime field--label-hidden field--item">14 07, 1989</div> <div class="field field--name-field-drupal-7-path field--type-string field--label-above"> <div class="field--label">Drupal 7 path</div> <div class="field--item">events/large-electron-positron-collider-first-injection</div> </div> <div class="field field--name-field-image field--type-image field--label-hidden field--item"> <img src="/sites/timeline.web.cern.ch/files/LEP-startup.jpg" width="598" height="480" alt="" typeof="foaf:Image" class="img-responsive" /> </div> <div class="field field--name-body field--type-text-with-summary field--label-hidden field--item"><p>With its 27-kilometre circumference, the Large Electron-Positron (LEP) collider was – and still is – the largest electron-positron accelerator ever built. LEP consisted of 5176 magnets and 128 accelerating cavities. CERN’s accelerator complex provided the particles and four enormous detectors, ALEPH, DELPHI, L3 and OPAL, observed the collisions.</p> <p>LEP was commissioned in July 1989 and the first beam circulated in the collider on 14 July. The picture above shows physicists grouped around a screen in the LEP control room at the moment of start-up. Carlo Rubbia, Director-General of CERN at the time, is in the centre and former Director-General Herwig Schopper is on his left. For seven years, the accelerator operated at 100 GeV, producing 17 million Z particles, uncharged carriers of the weak force. It was then upgraded for a second operation phase, with as many as 288 superconducting accelerating cavities added to double the energy and produce W bosons, also carriers of the weak force. LEP collider energy eventually topped 209 GeV in the year 2000.</p> <p>During 11 years of research, LEP and its experiments provided a detailed study of the electroweak interaction based on solid experimental foundations. Measurements performed at LEP also proved that there are three – and only three – generations of particles of matter. LEP was closed down on 2 November 2000 to make way for the construction of the LHC in the same tunnel.</p> </div> <div class="field field--name-field-timeline field--type-entity-reference field--label-inline"> <div class="field--label">Timeline</div> <div class="field--items"> <div class="field--item"><a href="/taxonomy/term/88" hreflang="en">The Large Electron-Positron Collider</a></div> <div class="field--item"><a href="/taxonomy/term/89" hreflang="en">The history of CERN</a></div> <div class="field--item"><a href="/taxonomy/term/92" hreflang="en">CERN accelerators</a></div> <div class="field--item"><a href="/taxonomy/term/87" hreflang="en">The search for the Higgs boson</a></div> </div> </div> </div> Wed, 13 Jun 2018 15:59:41 +0000 everisdrupal 390 at https://timeline.web.cern.ch LEP electron positron W boson Z boson Tantalising hints of the Higgs https://timeline.web.cern.ch/tantalising-hints-higgs <div data-history-node-id="378" class="node node--type-timeline-entry node--view-mode-rss ds-1col clearfix"> <div class="field field--name-field-date-historical-2 field--type-datetime field--label-hidden field--item">13 12, 2011</div> <div class="field field--name-field-drupal-7-path field--type-string field--label-above"> <div class="field--label">Drupal 7 path</div> <div class="field--item">events/tantalising-hints-of-the-higgs</div> </div> <div class="field field--name-body field--type-text-with-summary field--label-hidden field--item"><p>In a seminar today the ATLAS and CMS experiments present the status of their searches for the Standard Model Higgs boson. Their results are based on the analysis of considerably more data than those presented at the summer conferences, enough to make significant progress in the search for the Higgs boson, but not enough to make any conclusive statement on the existence or non-existence of the elusive Higgs. The main conclusion is that the Standard Model Higgs boson, if it exists, is most likely to have a mass constrained to the range 116-130 GeV by the ATLAS experiment, and 115-127 GeV by CMS. Tantalising hints were seen by both experiments in this mass region, but they were not yet strong enough to claim a discovery.</p> </div> <div class="field field--name-field-timeline field--type-entity-reference field--label-inline"> <div class="field--label">Timeline</div> <div class="field--items"> <div class="field--item"><a href="/taxonomy/term/87" hreflang="en">The search for the Higgs boson</a></div> <div class="field--item"><a href="/taxonomy/term/89" hreflang="en">The history of CERN</a></div> <div class="field--item"><a href="/taxonomy/term/93" hreflang="en">The Large Hadron Collider</a></div> </div> </div> </div> Wed, 13 Jun 2018 15:59:39 +0000 everisdrupal 378 at https://timeline.web.cern.ch Higgs boson LHC construction approved https://timeline.web.cern.ch/lhc-construction-approved <div data-history-node-id="375" class="node node--type-timeline-entry node--view-mode-rss ds-1col clearfix"> <div class="field field--name-field-date-historical-2 field--type-datetime field--label-hidden field--item">16 12, 1994</div> <div class="field field--name-field-drupal-7-path field--type-string field--label-above"> <div class="field--label">Drupal 7 path</div> <div class="field--item">events/lhc-construction-approved</div> </div> <div class="field field--name-body field--type-text-with-summary field--label-hidden field--item"><p>The CERN council <a href="http://press.web.cern.ch/press-releases/1994/12/cern-council-gives-go-ahead-large-hadron-collider">approves the construction of the Large Hadron Collider</a>. To achieve the project without enlarging CERN’s budget, they decide to build the accelerator in two stages.</p> </div> <div class="field field--name-field-timeline field--type-entity-reference field--label-inline"> <div class="field--label">Timeline</div> <div class="field--items"> <div class="field--item"><a href="/taxonomy/term/93" hreflang="en">The Large Hadron Collider</a></div> <div class="field--item"><a href="/taxonomy/term/87" hreflang="en">The search for the Higgs boson</a></div> </div> </div> </div> Wed, 13 Jun 2018 15:59:39 +0000 everisdrupal 375 at https://timeline.web.cern.ch LHC Building the LHC The LHC starts up https://timeline.web.cern.ch/lhc-starts <div data-history-node-id="374" class="node node--type-timeline-entry node--view-mode-rss ds-1col clearfix"> <div class="field field--name-field-date-historical-2 field--type-datetime field--label-hidden field--item">10 09, 2008</div> <div class="field field--name-field-drupal-7-path field--type-string field--label-above"> <div class="field--label">Drupal 7 path</div> <div class="field--item">events/the-lhc-starts-up</div> </div> <div class="field field--name-field-image field--type-image field--label-hidden field--item"> <img src="/sites/timeline.web.cern.ch/files/LHC-start-up.jpg" width="640" height="426" alt="" typeof="foaf:Image" class="img-responsive" /> </div> <div class="field field--name-body field--type-text-with-summary field--label-hidden field--item"><p>At 10.28am on 10 September 2008 a beam of protons is successfully steered around the 27-kilometre Large Hadron Collider (LHC) for the first time. The machine is ready to embark on a new era of discovery at the high-energy frontier.</p> <p>LHC experiments address questions such as what gives matter its mass, what the invisible 96% of the universe is made of, why nature prefers matter to antimatter and how matter evolved from the first instants of the universe’s existence.</p> <p>Explore the <a href="http://press.web.cern.ch/past-events/lhc-first-beam">resources prepared for press</a>.</p> </div> <div class="field field--name-field-timeline field--type-entity-reference field--label-inline"> <div class="field--label">Timeline</div> <div class="field--items"> <div class="field--item"><a href="/taxonomy/term/89" hreflang="en">The history of CERN</a></div> <div class="field--item"><a href="/taxonomy/term/92" hreflang="en">CERN accelerators</a></div> <div class="field--item"><a href="/taxonomy/term/93" hreflang="en">The Large Hadron Collider</a></div> <div class="field--item"><a href="/taxonomy/term/87" hreflang="en">The search for the Higgs boson</a></div> <div class="field--item"><a href="/taxonomy/term/147" hreflang="en">Archive of important events in CERN&#039;s history for press</a></div> </div> </div> </div> Wed, 13 Jun 2018 15:59:39 +0000 everisdrupal 374 at https://timeline.web.cern.ch LHC The history of CERN