The ATLAS Collaboration reports the first observation that nucleons near the edge of a nucleus have a different internal structure than those near its centre. An atomic nucleus is more complex than a ...

You can’t exactly take the ATLAS experiment on tour. At 7,000 tonnes and buried 100 metres underground at CERN, it’s not easy to move. So, for more than a decade, the ATLAS Collaboration has found ano...

While the Higgs mechanism is best known for breaking electroweak symmetry and giving fundamental particles mass, it can also leave a distinctive imprint on the polarisation of certain particles. A mas...

At 05:52 a.m. on 27 June 2026, the final protons of the Large Hadron Collider's third data-taking period circulated through the accelerator, bringing Run 3 to a close and marking the end of a remarkab...

YouTube video by CERN

The ATLAS Collaboration reports the first evidence of the simultaneous production of a photon and two neutral Z bosons at the LHC. The electroweak sector of the Standard Model combines the weak intera...

Despite its resounding success at describing high-energy phenomena, the Standard Model of particle physics provides no explanation for some of the fundamental questions of the Universe, such as the na...

The ATLAS Collaboration reports its first measurement of proton-oxygen collisions at the Large Hadron Collider (LHC). These results transform the ATLAS experiment into a cosmic-ray laboratory, helping...

The ATLAS Collaboration reports the first evidence of Higgs-boson production at high transverse momentum in decays to a pair of bottom quarks. Almost 15 years since its discovery by the ATLAS and CMS ...

For particle physicists, March means one thing: Moriond. Every spring, theorists and experimentalists from around the world gather at the Rencontres de Moriond conferences to present their latest resu...

The 2025 ATLAS Thesis Award ceremony. From left to right: ATLAS Collaboration Board Chair Davide Constanzo; ATLAS Thesis Awards Committee Chair Jean-François Arguin; ATLAS Thesis Award winners Elena M...

When particles burst from an LHC collision, they rarely leave a simple, single trail for physicists to follow. More often, they are high-energy quarks and gluons that erupt into jets, collimated spray...

One of the central questions in particle physics is how fundamental particles acquire mass. The top quark, as the heaviest known elementary particle, interacts most strongly with the Higgs boson. As s...

The top quark, the heaviest known elementary particle, has captivated physicists since its discovery in the 1990s and holds a privileged place within the Standard Model of particle physics. It has a v...

YouTube video by ATLAS Experiment

The ATLAS Collaboration reports its first observation of WWγ production – a rare process involving the simultaneous production of two W bosons and a photon. The weak force is one of the four fundament...

The strong force, unrivaled in strength yet confined to minuscule distances, produces unique bound states of quarks known as quarkonia. These are the strong-force equivalent of the hydrogen atom, cons...

All matter in the universe is made up of just two fundamental building blocks: quarks and leptons. Intriguingly, both have three distinct families or “generations”. For example, the electron and its a...

The ATLAS Collaboration finds evidence of Higgs-boson decays to muons and improves sensitivity to Higgs-boson decays to a Z boson and a photon. Since the discovery of the Higgs boson in 2012, physicis...

The top quark is a bit of a loner. While other quarks can join together to form bound states called hadrons, the top quark’s extremely short lifetime means it decays almost instantly – disappearing be...

Welcome to the tutorial page for the 2025 13 TeV beta release. Please, start by choosing your enviroment and continue as needed.

The ATLAS Collaboration celebrated the dedication, ingenuity and collaborative spirit of its members at the 8th Outstanding Achievement Awards. Winners of the ATLAS Outstanding Achievement Awards 2025...

One of the biggest open questions in particle physics today is how the Higgs boson interacts with itself. This “self-coupling” plays a pivotal role in determining the shape of the energy potential of ...