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 | 29 Mar 2022

Search for new physics in Higgs boson decays with displaced photons

The ATLAS Collaboration performed a new search for exotic Higgs-boson decays using the full dataset of 13 TeV proton-proton collisions delivered by the LHC between 2015 and 2018.

Physics Briefing | 28 Mar 2022

One Higgs boson found – could there be more?

Many theories suggest that the Higgs boson discovered in 2012 by the ATLAS Experiment is but the first to be observed from a larger Higgs family. A new ATLAS analysis searches for the presence of a new singly-charged Higgs boson.

Physics Briefing | 24 Mar 2022

ATLAS Live talk: Artificial Intelligence, Machine Learning and the Higgs boson with Dr. David Rousseau

On 31 March 2022 at 8pm CEST, Dr. David Rousseau will give a live public talk on the ATLAS Youtube Channel on the role artificial intelligence plays in particle physics research.

News | 23 Mar 2022

ATLAS reports first observation of single top-photon production

The ATLAS Collaboration announces the first observation of “tqγ production”: the associated production of a single top quark and a photon in proton-proton collisions at the LHC.

Physics Briefing | 15 Mar 2022

ATLAS seeks out unusual signatures of long-lived particles

The ATLAS Collaboration has devised a range of new strategies to look for long-lived particles with various possible characteristics. Four new results from this effort were presented at the recent Lepton-Photon and La Thuile conferences.

Physics Briefing | 14 Mar 2022

Summary of new ATLAS results from 2022 Winter Conferences

The winter conference season is in full swing! 2022 marks the return of full auditoriums and coffee-break chats, as the La Thuile and Rencontres de Moriond conferences welcome participants to venues in the Italian Alps. These are the first large-scale, international particle physics conferences to be held in person in the COVID era – reuniting experimentalists and theorists after almost two years of virtual meetings.

News | 10 Mar 2022

And the ATLAS Thesis Awards go to…

Behind nearly every great ATLAS result lies an outstanding PhD student! Students are a key cohort of the ATLAS Collaboration, making critical contributions to the experiment while working on their degree. Every year, the Collaboration comes together to celebrate their work in the context of the ATLAS Thesis Awards.

News | 08 Mar 2022

ATLAS event selection system readies for LHC Run 3

The ATLAS trigger system operated extremely successfully during Run 1 (2009–2013) and Run 2 (2015–2018) of the LHC. It is now undergoing various upgrades in preparation for the upcoming Run-3 data-taking period, which will see a moderate increase in the rate of collisions inside the experiment.

Experiment Briefing | 28 Feb 2022

Looking for the invisible with the Higgs boson

According to the Standard Model, most particles get their mass through an interaction with the Higgs field. If dark-matter particles acquire their mass in the same way, a Higgs boson created in an LHC collision might sometimes decay into a pair of “invisible” dark-matter particles. The ATLAS Collaboration has released a new search for invisible Higgs-boson decays using the full Run-2 dataset.

Physics Briefing | 17 Feb 2022

ATLAS Live talk: Exploring electroweak phenomena with Dr. Karolos Potamianos

On 17 February 2022 at 8pm CET, Dr. Karolos Potamianos will give a live public talk on the ATLAS Youtube Channel on the study of the electroweak force and the role it plays in the Universe.

News | 08 Feb 2022

ATLAS sees a difference between beauty and charm decays of the Higgs boson

Physicists from the ATLAS Collaboration have combined two measurements of the interaction strength of the Higgs boson with two different pairs of quarks. This allows physicists to test a hypothesis that the Higgs boson interacts with charm quarks (which are second-generation quarks) in the same way it interacts with beauty quarks (third-generation quarks).

Physics Briefing | 01 Feb 2022

Developing the ATLAS End-Cap Toroids: a personal history

Former ATLAS engineer Elwyn Baynham shares his experience as part of the team developing the ATLAS End-Cap Toroids. His story paints a personal picture of the history of these incredible magnets.

Blog | 26 Jan 2022

Upgraded ATLAS Liquid Argon Calorimeter ready for next LHC operation

The ATLAS Collaboration has completed the installation of “Phase-I” upgrades of the Liquid Argon Calorimeter (LAr). The upgrades improve the read-out speed of the calorimeter’s electronics and provide more efficient event-selection capabilities. These improvements will be pivotal for data-taking during the coming high-intensity runs of the LHC.

Experiment Briefing | 25 Jan 2022

ATLAS gives new insight into the internal structure of the proton

The ATLAS Collaboration has just released a new paper combining LHC and HERA data to determine Parton Distribution Functions (PDFs), which describe what fraction of a proton’s momentum is taken by its constituent quarks and gluons.

Physics Briefing | 12 Jan 2022

Discovery channels join forces for detailed investigation of the Higgs boson

The ATLAS Collaboration has released updated measurements of the Higgs boson properties using the full LHC Run-2 dataset (recorded 2015-2018).

Physics Briefing | 11 Jan 2022

Summary of new ATLAS results from Lepton Photon 2021

The 30th International Symposium on Lepton Photon Interactions at High Energies (Lepton Photon 2021) kicks off today. Explore the ATLAS results that will be presented.

News | 10 Jan 2022

Building an ATLAS gingerbread wonderland

When I received an email from the ATLAS outreach coordinators in October 2021, asking if I would help them make an ATLAS-inspired gingerbread village for this year’s card, I couldn’t refuse an opportunity for another fun “Physics Cakes” project.

Blog | 24 Dec 2021

New ATLAS result seeks to unravel the charge–flavour mystery

Could there be another source of asymmetry in the Universe? ATLAS physicists are studying the differences between positively- and negatively-charged electrons and muons, looking for signs of charge–lepton-flavour symmetry breaking.

Physics Briefing | 17 Dec 2021

ATLAS without Frontiers

For several years, the ICTP Physics Without Frontiers (PWF) programme has been heavily involved with outreach activities to inspire, train and educate young and motivated physics students worldwide. Several members of the ATLAS Collaboration very active in this programme.

Blog | 14 Dec 2021

Search for elusive “di-Higgs production” reaches new milestone

According to the Standard Model, the Higgs boson can interact with itself, resulting in the simultaneous production of two Higgs bosons ("di-Higgs production"). In a new result, the ATLAS Collaboration combines three di-Higgs decay channels to reach the best limits yet on di-Higgs production.

Physics Briefing | 19 Nov 2021

ATLAS Live talk: Building the Data Haystack with Dr Heather Russell

On 22 November 2021 at 8pm CET, Dr. Heather Russell will give a live public talk on the ATLAS Youtube Channel on the "trigger", the ATLAS event selection system.

News | 18 Nov 2021

Detectors for a new era of ATLAS physics

4 November 2021, Geneva. The ATLAS Experiment at CERN welcomes a brand-new detector: the Muon New Small Wheel system. Its successful installation follows nearly a decade of design and construction, and marks a major milestone in ATLAS’ high-luminosity era.

News | 04 Nov 2021

Teaching established software new tricks

Following several years of development, ATLAS Collaboration has launched a new "multithreaded" release of its analysis software, Athena.

Experiment Briefing | 15 Oct 2021

Bringing new life to ATLAS data

The ATLAS Collaboration is breathing new life into its LHC Run-2 dataset, recorded from 2015 to 2018. Physicists will be reprocessing the entire dataset – nearly 18 PB of collision data – using an updated version of the ATLAS offline analysis software (Athena). Not only will this improve ATLAS physics measurements and searches, it will also position the Collaboration well for the upcoming challenges of Run 3 and beyond.

News | 15 Oct 2021