Researchers at the ATLAS Experiment are searching for a hidden “dark sector”, a realm of new sets of particles and forces that interact very weakly with the known matter, potentially producing elusive and puzzling signatures. In two new results, ATLAS physicists hunted for dark-sector physics using these distinctive jet signatures.

ATLAS physicists have measured the cross section for W bosons with transverse masses between 200 GeV and 5 TeV.

Last week, the ATLAS Collaboration presented new results at the Quark Matter 2025 conference, held in Frankfurt am Main (Germany). From detailed studies of the quark-gluon plasma’s collective motion to new measurements in ultra-peripheral collisions, ATLAS is providing new insight into the fascinating behaviour of heavy-ion collisions and the quark–gluon structure of nuclei.

Last week, at the Rencontres de Moriond conference, the ATLAS Collaboration brought physicists a step closer to understanding the nature of the electroweak symmetry-breaking mechanism.

The ATLAS Collaboration at CERN has been awarded the Breakthrough Prize in Fundamental Physics for its pioneering studies of the high-energy collisions from the Large Hadron Collider (LHC).

While the discovery of the Higgs boson in 2012 by the ATLAS and CMS Collaborations remains the LHC's crowning achievement, the ATLAS Collaboration has since produced a wealth of groundbreaking results that continue to reshape particle physics. In this feature article, Andreas Hoecker delves into the remarkable breakthroughs uncovered by ATLAS using Run 2 data.

This weekend, the ALICE, ATLAS, CMS and LHCb collaborations at the Large Hadron Collider at CERN were honoured with the Breakthrough Prize in Fundamental Physics by the Breakthrough Prize Foundation. The prize is awarded to the four collaborations, which unite thousands of researchers from more than 70 countries, and concerns the papers authored based on LHC Run-2 data up to July 2024. It was received by the spokespersons who led the collaborations during that time.

The ATLAS Collaboration reported the first evidence – with 3.3σ significance – of vector boson scattering involving longitudinally polarised, same-sign W bosons

The ATLAS Collaboration submitted four documents to the European Strategy Group (ESG), namely, an overview of the extensive ATLAS detector upgrade for the HL-LHC, a summary of the software and computing preparations to address the HL-LHC challenges, a joint update with CMS on HL-LHC physics expectations, and a joint document on prospectives for flavour physics.

In a new study submitted to Physical Review D, scientists at the ATLAS experiment leveraged the muon spectrometer’s size and precision tracking capabilities to search for neutral LLPs by identifying displaced decay vertices.

The ATLAS Collaboration has published two new papers investigating the production of tau leptons in high energy proton-proton collisions.

The ATLAS Collaboration at CERN performed its most precise single measurement of the mass of the top quark, using high-transverse-momentum (“boosted”) top quarks.

Every Spring, all eyes turn to La Thuile (Italy) for the arrival of the annual Recontres de Moriond conferences. Explore the full list of new ATLAS results presented at Moriond.

The ATLAS Collaboration embarks on a new chapter under the leadership of Spokesperson Stéphane Willocq (University of Massachusetts Amherst).

Among the more than 5500 members of the ATLAS Collaboration, PhD students play a vital role in advancing the experiment while pursuing their degrees. Every year, the ATLAS Thesis Awards celebrate their outstanding achievements, recognising the significant impact of their research on physics analyses, detector advancements, and software development.

The ATLAS Collaboration announces the first observation of “VVZ production” – a rare combination of three massive vector bosons produced simultaneously at the LHC.

The ATLAS Collaboration has released its first open data of heavy-ion collisions for research purposes. This dataset features lead-ion (Pb-Pb) collisions at an energy of 5 TeV per nucleon pair, recorded in 2015 as part of the Large Hadron Collider’s second operation period (LHC Run 2). Today’s release is the highest energy heavy-ion collision data ever made publicly available and the first LHC Run 2 heavy-ion open dataset.

This week, the ATLAS Collaboration announced a new high-precision measurement of the lifetime of the B0 meson. The B0 meson is composed of a bottom quark and a down antiquark. Measurements of its lifetime – the average time it exists before decaying – provide an exceptional probe of physics processes beyond the Standard Model.

The ATLAS Collaboration at CERN has observed top-quark pair production in lead-lead ion collisions, marking the first observation of this process in nucleus-nucleus interactions.

At this week’s Higgs2024 conference, the ATLAS Collaboration unveiled the first LHC search for tri-Higgs production – a process over 600,000 times rarer than the production of a single Higgs boson.

ATLAS researchers are using innovative new techniques in their analysis of off-shell Higgs-boson production.

The ATLAS Collaboration has released three major searches for new-physics phenomena, all utilising new advancements in particle tagging.

Two new studies from the ATLAS Collaboration explore how top-quark pairs are produced alongside heavy-flavour quarks, like bottom and charm.

In an article published today in Nature, the ATLAS collaboration reports how it succeeded in observing quantum entanglement at the LHC for the first time.

New measurements by the ATLAS Collaboration show that studying Higgs-boson decays into tau-lepton pairs can reveal not only its interactions with fermions, but also give insights into Higgs-boson production at the LHC. ATLAS researchers performed two kinds of cross-section measurements in their new analysis of Higgs-boson decays to tau leptons.