Using the Higgs boson to search for dark photons

The ATLAS Collaboration has been looking for signs of dark photons in data collected by the experiment during LHC Run 2 (2015-2018). Their newest search targets, for the first time in ATLAS, the production of a Higgs boson in association with a Z boson, with subsequent decay of the Higgs into a photon and a dark photon.

Physics Briefing |

ATLAS Highlights from ICHEP 2022

At ICHEP 2022, the ATLAS Collaboration presented the results of 30 new studies, spanning from Higgs boson and Standard Model measurements to searches for new phenomena.

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ATLAS observes potential four-charm tetraquark

In a new analysis presented at the ICHEP 2022 conference, ATLAS physicists found evidence of a four-charm-quark excess. Like the LHCb Collaboration, ATLAS sees both the X(6900) particle and a broad structure at threshold.

Physics Briefing |

ATLAS measures quantum interference when protons bounce off each other

In a new result presented at ICHEP 2022, ATLAS physicists set out to measure proton scattering at microradian angles and study this quantum interference.

Physics Briefing |

ATLAS measures joint polarisation of W and Z bosons

In a new result presented at the ICHEP 2022 conference, ATLAS physicists have been able to observe events with both a W and Z boson simultaneously polarised longitudinally for the very first time.

Physics Briefing |

Summary of new ATLAS results from ICHEP 2022

The 2022 International Conference on High Energy Physics (ICHEP) kicks off this week in Bologna, Italy. The ATLAS Collaboration will be unveiling a wide range of new results, exploring the full potential of the dataset collected during LHC Run 2 (2015-2018).

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ATLAS Experiment records “first physics” at new high-energy frontier

“We have proton collisions in the ATLAS experiment.” At 16.47 CEST, the Large Hadron Collider (LHC) officially kicked off its third period of operation (Run 3). The LHC is colliding proton beams at a world-record-breaking energy of 13.6 tera electron volts (TeV). The higher beam energy and intensity of Run 3 will allow the ATLAS experiment to push the very limits of its physics research.

Press Statement |

LHC Run 3 starts

The Large Hadron Collider is ready to once again start delivering proton collisions to experiments, this time at an unprecedented energy of 13.6 TeV, marking the start of the accelerator’s third run of data taking for physics.

Press Statement |

ATLAS explores the self-interaction of the Higgs boson

In the most recent effort to constrain the Higgs self-coupling constant, ATLAS physicists used the full Run 2 dataset (collected during 2015-2018) to perform a combined study on the production of a single Higgs boson and two Higgs bosons. This single-Higgs analysis was featured in a paper released in Nature today, looking back on 10 years of Higgs boson research at the ATLAS Experiment

Physics Briefing |

10 years of Higgs research

The ATLAS Collaboration at CERN has released its most comprehensive overview of the Higgs boson. The new paper, published in the journal Nature, comes exactly ten years after ATLAS announced the discovery of the Higgs boson. In celebration of this anniversary, a special all-day symposium on the Higgs boson is currently underway at CERN.

Press Statement |

ATLAS & CMS Higgs study 2022

The collaborations have used the largest samples of proton–proton collision data recorded so far by the experiments to study the unique particle in unprecedented detail.

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ATLAS Pixel detector in Run 3

The ATLAS experiment at the Large Hadron Collider (LHC) is on the eve of a new data harvest with the restart of the LHC for Run 3. The upcoming four-year run will provide a dataset nearly twice the size of what was collected in Run 2 (2015–2018).

Physics Briefing |

Outstanding Achievement Awards

The ATLAS Collaboration held the 6th Outstanding Achievement Awards Ceremony at CERN on 23 June 2022. Once every two years, these awards give recognition to the invaluable technical work made across the collaboration in all areas.

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Harnessing a supercomputer for ATLAS

ATLAS researchers are exploring the potential of High Performance Computing (HPC). HPC harnesses the power of purpose-built supercomputers constructed from specialised hardware, and is used widely in other scientific disciplines.

Experiment Briefing |

ATLAS measures symmetry of Higgs boson decays to tau leptons

The ATLAS Collaboration has just released a new measurement of the CP properties of H→ττ interactions. The study of H→ττ allows researchers to understand the CP-nature of Higgs boson interactions.

Physics Briefing |

Searches united

The ATLAS Collaboration has released a new combined search for heavy vector bosons, which includes 13 individual searches studying different final states. The new combination includes, for the first time, a dedicated search for heavy particles decaying to third-generation leptons (taus).

Physics Briefing |

ATLAS looks for top quarks going against the current

Using the full Run-2 dataset, the ATLAS Collaboration has published four analyses searching for flavour-changing neutral currents in the production and decay of the top quark. The results study top-quark processes involving all four neutral bosons: the photon, gluon, Z boson and Higgs boson.

Physics Briefing |

Summary of new ATLAS results from LHCP 2022

The tenth edition of the annual conference on Large Hadron Collider physics (LHCP 2022) begins today in video-conference rooms around the world.

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Looking inside trillion degree matter with ATLAS at the LHC

Stars, planets, animals, plants, you and me – everything that can be directly observed in our Universe is ordinary matter. But the Universe didn’t always look this way. This ATLAS feature describes the quark-gluon plasma, a unique state of matter that existed shortly after the Big Bang. The nature and properties of this matter are being revealed at CERN’s ATLAS Experiment.



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Beams splash in ATLAS

After over three years of upgrade and maintenance work, proton beams are back in the Large Hadron Collider! Friday 22 April 2022 marked the start of the LHC’s third operation period (Run 3), which will see a record number of collisions in the ATLAS detector.

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Mass matters – but it isn't the only thing!

The ATLAS Collaboration finds evidence of parton mass, colour-charge and radiation-pattern dependence in quark-gluon-plasma induced energy loss.

Physics Briefing |

ATLAS gives new insight into dijet suppression in heavy-ion collisions

At the recent Quark Matter 2022 conference in Krakow, Poland, members of the ATLAS Collaboration presented a new study of “jets” of particles travelling through the QGP. The result provides new insight into dijet suppression due to interactions with the nuclear medium.

Physics Briefing |

ATLAS observes pairs of tau particles in heavy-ion collisions

Today at the Quark Matter 2022 Conference, the ATLAS Collaboration announced the observation of tau-lepton pairs created when particles of light – or photons – interact during lead-ion collisions. The result opens a new avenue for measuring how magnetic the tau lepton is – a property sensitive to new particles beyond the Standard Model.

Physics Briefing |

ATLAS highlights from the Moriond 2022 conference

As one of the most exciting and promising experiments for new crucial discoveries in the field of high-energy particle physics, ATLAS contributed many novel results presented in dedicated talks at the recent Rencontres de Moriond conference.

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ATLAS strengthens its search for supersymmetry

Where is all the new physics? Could it be sneaking past the standard searches? ATLAS researchers have developed innovative ways to search for new particles, improving their search programme to ensure they have the best chance of discovering new physics in Run 3 of the LHC.

Physics Briefing |