Searching for new physics using asymmetric top-quark events

Finding the differences between these types of matter – while extremely challenging – could reveal well-hidden effects that hint at the existence of new particles and interactions. In a new result presented at the TOP 2021 conference, the ATLAS Collaboration probed the heaviest-known elementary particle, the top quark, in search of these effects.

Physics Briefing | 13 Sep 2021

ATLAS highlights from the EPS-HEP 2021 conference

ATLAS’ vibrant physics programme was on full display at EPS-HEP 2021, with members presenting 26 new physics analyses among other key recent results. These were shown in 63 presentations and 45 posters over the five days.  

News | 04 Aug 2021

Hunting for forbidden decays of the Z boson

In a new study, the ATLAS Collaboration looked for Z bosons decaying into an electron and an anti-muon, or into a muon and a positron.

Physics Briefing | 03 Aug 2021

ATLAS measures key Higgs boson interaction with high precision

The ATLAS Collaboration releases new measurements of the Higgs-boson decay to tau leptons. The result provides new insight into the “Yukawa coupling”, a key interaction of the Higgs boson. 

Physics Briefing | 02 Aug 2021

Two Higgs bosons are better than one

One of the long-term goals of the LHC is to measure the Higgs-boson self-coupling, which in turn can give us clues about the formation of the early Universe. This self-coupling can only be measured directly by studying the production of pairs of Higgs bosons (HH). 

Physics Briefing | 30 Jul 2021

Probing new physics with pairs of Higgs bosons

The ATLAS Collaboration has released a new result searching for pairs of Higgs bosons (HH) produced by new particles. The Higgs bosons would then each decay into pairs of bottom (b) quarks – known as the '4b decay channel'.

Physics Briefing | 28 Jul 2021

ATLAS reports first observation of WWW production

The ATLAS Collaboration announces the first observation of “WWW production”: the simultaneous creation of three massive W bosons in high-energy LHC collisions.

Physics Briefing | 26 Jul 2021

Summary of new ATLAS results from EPS-HEP 2021

The European Physical Society Conference on High Energy Physics (EPS-HEP 2021) kicks off today. Explore the ATLAS results that will be presented.

News | 26 Jul 2021

The Last Quark

Twenty-five years on from the discovery of the top quark, ATLAS physicist Richard Hawkings discusses the history of the particle's discovery, its place in the Standard Model and what it has still yet to tell us.

Feature | 23 Jul 2021

Shining light on the strong interaction: ATLAS measures photon pair production

What can particles of light – photons – tell us about the inner workings of the Standard Model? A new paper from the ATLAS Collaboration measures pairs of photons to improve the understanding of a fundamental force of Nature – the strong force – and thus scrutinise the theoretical models that underpin high-energy physics research. 

Physics Briefing | 22 Jul 2021

Live from the ATLAS experiment

In celebration of the lowering of the first New Small Wheel detector, CERN is hosting a 360° live event from the ATLAS cavern! Tune in on Thursday 15 July at 5pm CEST.

News | 14 Jul 2021

Studying “Little Bangs”: exotic collisions probe the size of quark-gluon plasma

A new result from the ATLAS Collaboration studies the interactions of photons – particles of light – with lead nuclei at the Large Hadron Collider (LHC). Using new data collection techniques, physicists revealed an unexpected similarity to the experimental signatures of the quark–gluon plasma.

Physics Briefing | 13 Jul 2021

ATLAS Live talk: Deciphering the Higgs boson with Dr Hongtao Yang

On 1 July 2021, Dr. Hongtao Yang will be giving a live public talk, sharing the story of the Higgs boson's discovery by the ATLAS and CMS experiments. He will explain what ATLAS physicists have learned about this fascinating particle so far, and describe the next steps in its exploration.

News | 29 Jun 2021

ATLAS celebrates results of 1000 collision papers

The ATLAS Collaboration celebrates the creativity, wealth and scientific impact enshrined in its 1000 papers using LHC collision data. This work – together with that carried out by its sister experiments at the LHC – represents a diversified physics programme that is unprecedented and unequalled in physics research to date.

News | 18 Jun 2021

The hunt for higgsinos reaches new limits

The ATLAS Collaboration has released three new searches for "higgsinos" - the super-partner of the Higgs boson.

Physics Briefing | 10 Jun 2021

Heavyweight champions: a search for new heavy W’ bosons with the ATLAS detector

A new search from the ATLAS Collaboration, released this week at the Large Hadron Collider Physics conference (LHCP 2021), sets limits on the mass of the W’ boson.

Physics Briefing | 09 Jun 2021

ATLAS measures the polarisation of top quarks and antiquarks

In a new result presented by the ATLAS Collaboration, physicists have measured – for the first time – the full polarisation vectors for both top quarks and antiquarks. 

Physics Briefing | 08 Jun 2021

New search for charming decay of the Higgs boson

At the LHCP2021 conference, the ATLAS Collaboration presents a new direct search for the decay of the Higgs boson to charm quarks. Observing this decay would give physicists new insight into the Higgs boson’s relationship with the second generation of matter particles.

Physics Briefing | 07 Jun 2021

Summary of new ATLAS results from LHCP 2021

The ninth annual conference on Large Hadron Collider physics (LHCP 2021) begins today in video-conference rooms around the world.

News | 07 Jun 2021

ATLAS Live talk: How to study matter at a trillion degrees with Dr. Anne Sickles

Soon after the Big Bang, the Universe was too hot for normal matter to exist. Instead, it was made up of an extremely hot liquid of quarks and gluons: the quark-gluon plasma (QGP). In this live talk, Dr. Anne Marie Sickles explains how physicists at the ATLAS experiment are studying the QGP and what they've have learned.

News | 05 Jun 2021

First ATLAS New Small Wheel nears completion

On Friday 28 May 2021, teams of physicists and engineers installed the final "wedge" of the first ATLAS New Small Wheel detector. This was an important milestone for the Collaboration, in preparation for the wheel’s installation in the ATLAS cavern later this summer.

News | 04 Jun 2021

ATLAS Live talk: From Data to Discovery with Dr. James Catmore

Making a scientific breakthrough in 2021 requires more than just a microscope – most scientists rely on powerful computers and ingenious software to carry out their research. In this live talk, Dr. James Catmore explains the advanced computing and software techniques used by the ATLAS Experiment.

News | 10 May 2021

Supporting talented students with the ATLAS PhD Grant

On 13 April 2021, the recipients of this year's ATLAS PhD Grant were celebrated in an online ceremony. These talented and motivated students will receive 1.5 years of funding for their studies at CERN, giving them the opportunity to enhance their doctoral studies in a one-of-a-kind research environment.

News | 04 May 2021

In conversation with John Rutherfoord, a leading designer of the ATLAS Calorimeter

John P. Rutherfoord is a professor at the University of Arizona and a long-standing member of the ATLAS Collaboration. His extensive career has taken him from searching for the Upsilon particle at Fermilab to CERN to leading the design and development of the ATLAS Forward Calorimeter. 

Portrait | 22 Apr 2021

Building community in virtual events

Since 2017, the ATLAS Early Career Scientist Board (ECSB) and Analysis Software Tutorial organisers have been teaming up to run a week-long introductory event for new ATLAS members. Induction Day welcomes new members to the collaboration by giving them an overview of the plethora of activities that take place within the ATLAS Collaboration.

Blog | 20 Apr 2021