Measuring the delicate balance of lepton flavours

In a new result presented at Moriond EW, physicists at the ATLAS Collaboration tested lepton flavour universality between muons and electrons. The precision of the result stands as the best yet-achieved in W-boson decays by a single experiment and surpasses the world average.

Physics Briefing |

New ATLAS Results at Moriond24

This year, the start of Spring marks the beginning of the conference season for particle physicists! All eyes turn to La Thuile, Italy, where the annual Recontres de Moriond conferences will be held.

News |

ATLAS searches for new particles in familiar decays

In a new result, researchers conducted a novel search of data collected during Run 2 of the LHC, searching for heavy new particles that could fit the 2HDM or 2HDM+S models.

Physics Briefing |

ATLAS welcomes new management

The ATLAS Collaboration at CERN welcomes a new member to its management team. Martin Aleksa (CERN) joins as Technical Coordinator for the experiment, picking up the torch from Ludovico Pontecorvo (CERN).

News |

Meet the winners of the 2023 ATLAS Thesis Awards

The ATLAS Collaboration celebrated the achievements of its exceptional PhD students at the recent Thesis Awards ceremony. Established in 2010, the ATLAS Thesis Awards recognize the remarkable contributions made by students to the ATLAS Collaboration through their doctoral theses.

News |

In conversation with Ana Henriques Correia, a key player in the development of the ATLAS Calorimeter

Ana Henriques arrived at CERN in 1988 as a summer student, and never wanted to leave. She assumed the roles of technical coordinator and project leader of the ATLAS Tile Calorimeter, being involved in its design, construction, and installation processes.

Portrait |

Exploring the Weak Force with ATLAS

As we celebrate the 50th anniversary of the observation of neutral currents and the 40th anniversary of the W/Z boson discovery, we take a look back on the 13 years of ATLAS research into the weak force.

News |

Searching for supersymmetric needles in the LHC haystack

The ATLAS Collaboration has published three new results in this challenging area, using Boosted Decision Trees (BDTs) to isolate potential signals and ultimately set stringent constraints on the masses of SUSY particles.

Physics Briefing |

ATLAS Live talk: Chasing the unknown (with the very well known!) by Dr Ludovica Aperio Bella

On 16 November 2023 at 6pm CET, Dr. Ludovica Aperio Bella will give a live public talk on the ATLAS Youtube Channel about precision measurements at the LHC.

News |

From internship to authorship: one student’s unique journey in ATLAS

Lukas Kretschmann, a physics student at the University of Wuppertal in Germany, shares his journey in the ATLAS Collaboration – which began as a high-school student!

Blog |

ATLAS Week: through the eyes of students

ATLAS Week is an opportunity for young physicists to present and discuss their work. ATLAS students Sarah and Bruna were at the last ATLAS Week in Vancouver, Canada, and share what the experience was like for them.

Blog |

ATLAS gains momentum in study of charmonium

The ATLAS Collaboration has measured the production cross section of the J/ψ and ψ(2S) charmonium states in terms of the transverse momentum and the rapidity. For both states, they examined the widest range of transverse momentum so far, thus providing new input for theoretical models.

Physics Briefing |

ATLAS and CMS unite to weigh in on the top quark

The ATLAS and CMS Experiments at CERN have just released a new measurement of the mass of the top quark. The new result combines 15 previous measurements to give the most precise determination of the top-quark mass to date.

Physics Briefing |

ATLAS achieves highest-energy detection of quantum entanglement

In a new result from the ATLAS Collaboration, physicists observed – for the first time – quantum entanglement between a pair of quarks. This is the highest-energy measurement of entanglement to date.

Physics Briefing |

ATLAS measures strength of the strong force with record precision

The result showcases the power of the LHC to push the precision frontier and improve our understanding of nature.

Press Statement |

ATLAS Live talk: How does ATLAS study heavy-ion collisions?

On 14 September at 6pm CEST, Dr. Martin Rybar and Dr. Peter Steinberg will give a live public talk on the ATLAS Youtube Channel on how the ATLAS experiment records heavy-ion collisions.

News |

A summer for science

For many students, a summer internship is a rite of passage — and a gateway to future jobs. Looking for a valuable glimpse into what a future in physics might hold, dozens of university students from around the world headed to CERN to participate in the Summer Student Programme and engage with cutting-edge scientific research at the ATLAS Experiment. With the support of their supervisors, these students have been deepening their knowledge of particle physics, engineering and computing through challenging projects. These are the stories of 12 of these students.

News |

ATLAS observes top quarks in heavy-ion collisions

The ATLAS Collaboration at CERN observes the production of top-quark pairs in proton-lead ion collisions. ATLAS’ new result confirms and builds upon an earlier observation made by the CMS Collaboration, expanding it into a new decay channel.

Physics Briefing |

When jets go dark

For the very first time, the ATLAS Collaboration has searched for dark jets that closely resemble QCD jets. Instead of originating from Standard-Model particles, these dark jets would be produced through a new, heavy particle called the Z' boson.

Physics Briefing |

Summary of new ATLAS results from Quark Matter 2023

The ATLAS Collaboration has prepared a variety of new results for the Quark Matter conference, focusing on the study of collisions involving lead ions, xenon, and lead ions with protons.

News |

ATLAS measures ZZ production using Run-3 data and a new slim data format

The ATLAS Collaboration has just released a new measurement of the production cross section of two Z bosons. This highlight result examines data collected during Run 3 of the LHC and pioneers the use of PHYSLITE, a new, reduced data format that requires significantly less storage.

Physics Briefing |

ATLAS searches for new phenomena using unsupervised machine learning for anomaly detection

In a new paper submitted to Phys. Rev. Lett., the ATLAS Collaboration pioneers the use of unsupervised machine learning to search for anomalous collision events which could be from new-physics phenomena.

Physics Briefing |

Quest for the curious magnetic monopole continues

In a new study presented at the EPS-HEP 2023 conference, the ATLAS Collaboration combed through the full LHC Run-2 dataset (recorded 2015-2018) in search for magnetic monopoles and HECOs (see Figure 1). The result places some of the tightest limits yet on the production rate of magnetic monopoles.

Physics Briefing |

ATLAS releases comprehensive review of supersymmetric dark matter

In new results presented today, the ATLAS Collaboration provides its most comprehensive overview of the searches for weakly-interacting supersymmetric particles. By developing new search algorithms and exploiting machine learning techniques, researchers have probed deep into this difficult-to-reach territory.

Physics Briefing |

Three’s no crowd: ATLAS measures tri-boson production

The ATLAS Collaboration has announced the first observation of two different tri-boson processes: the simultaneous production of a W boson with two photons (Wγγ) and the production of a W boson, a Z boson and a photon (WZγ). The production of a Z boson with two photons (Zγγ) was first observed in 2016 using data from LHC Run 1 (2010-2013). In a new publication, the ATLAS Collaboration expanded the scope of this initial observation using Run 2 data.

Physics Briefing |