Students step into the limelight: ATLAS awards excellent PhD theses

ATLAS PhD students are a key cohort of the Collaboration, making unique and crucial contributions to the experiment while working on their degree. Every year, their work is celebrated in the context of the ATLAS Thesis Awards.

News | 17 Feb 2021

ATLAS recognises the outstanding achievements of Collaboration members

The 2020 ATLAS Outstanding Achievement Awards ceremony was held online on 11 February 2021. Established in 2014, the awards recognise outstanding contributions in support of the ATLAS experiment, covering all areas except physics analysis. 

News | 16 Feb 2021

ATLAS finds evidence of a rare Higgs boson Dalitz decay to two leptons and a photon

ATLAS finds first evidence of the Higgs boson decaying to two leptons and a photon. This is one of the rarest Higgs boson decays yet seen at the LHC, with striking features that presented unique challenges for the ATLAS experiment.

Physics Briefing | 02 Feb 2021

Teaching university students with real ATLAS data

ATLAS PhD student Meirin Oan Evans explores how the University of Sussex is incorporating ATLAS Open Data into their teaching – and shares his experience using this incredible resource.

Blog | 27 Jan 2021

2020: an unprecedented year in review

Despite the huge challenges of the COVID-19 pandemic, last year saw excellent successes for the ATLAS Collaboration, including first-of-a-kind physics results and great headway made on detector upgrades.

News | 06 Jan 2021

Studying the Higgs boson in its most common – yet uncommonly challenging – decay channel

New results from the ATLAS Collaboration focus on different production modes of the Higgs boson decaying into b-quarks, capitalising on the power of machine learning to better discriminate this particular process from other proton collision events.

Physics Briefing | 01 Dec 2020

ATLAS releases new open software

The ATLAS Collaboration has just released a collection of 200 software packages that make up the Trigger and Data Acquisition System (TDAQ). With this new release, most ATLAS software is now open – reinforcing the Collaboration’s ongoing commitment to open science.

News | 20 Nov 2020

Refining the picture of the Higgs boson

A new result from the ATLAS Collaboration, released for the Higgs 2020 conference, aims at enriching the Higgs picture by studying its WW* decays.

Physics Briefing | 19 Nov 2020

Higgs boson probes for new phenomena

ATLAS scientists are implementing a new strategy in the search for physics beyond the Standard Model – one that combines measurements across the full spectrum of the Collaboration's research programme.

Physics Briefing | 28 Oct 2020

Leptons at a distance: a new search for long-lived particles

ATLAS researchers are broadening their extensive search programme to look for more unusual signatures of unknown physics, such as long-lived particles. A theory that naturally motivates long-lived particles is supersymmetry (SUSY). A new search from the ATLAS Collaboration – released this week for the 5th International Conference on Particle Physics and Astrophysics (ICPPA-2020) – looks for the superpartners of the electron, muon and tau lepton

Physics Briefing | 07 Oct 2020

Unraveling Nature's secrets: vector boson scattering at the LHC

In 2017, the ATLAS and CMS Collaborations announced the detection of a never-before-observed process: vector boson scattering.

Feature | 22 Sep 2020

Exploring the “coolest” mock-up

It was in 2014, just a few months after my transition from ALICE to ATLAS, that I saw the mock-up for the first time: a full-scale wooden reproduction of the central portion of the ATLAS experiment, measuring some 8 metres high and wide.

Blog | 10 Sep 2020

Z bosons zoom through quark–gluon plasma as jets quench

With new data from the LHC, ATLAS physicists have measured jet-quenching phenomena in the quark–gluon plasma with help of Z bosons.

Physics Briefing | 25 Aug 2020

ATLAS highlights presented at the world's largest particle-physics conference

As major players in the field of particle physics, the LHC collaborations contributed many new results, most of which exploited the full Run 2 dataset, recorded in 2015 to 2018. ATLAS physicists contributed 35 new results, and gave 85 talks in the parallel and plenary sessions. Their contributions spanned a wide range of topics, from precision measurements and searches for new phenomena to detector performance and R&D, as well as diversity and outreach.

News | 08 Aug 2020

Rare phenomenon observed by ATLAS features the LHC as a high-energy photon collider

During the International Conference on High-Energy Physics (ICHEP 2020), the ATLAS Collaboration presented the first observation of photon collisions producing pairs of W bosons, elementary particles that carry the weak force, one of the four fundamental forces. The result demonstrates a new way of using the LHC, namely as a high-energy photon collider directly probing electroweak interactions. It confirms one of the main predictions of electroweak theory – that force carriers can interact with themselves – and provides new ways to probe it.

Press Statement | 05 Aug 2020

ATLAS observes W-boson pair production from light colliding with light

The ATLAS Collaboration has announced the first observation of two W bosons produced from the scattering of two photons — particles of light – at the International Conference on High-Energy Physics (ICHEP 2020).

Physics Briefing | 05 Aug 2020

CERN experiments announce first indications of a rare Higgs boson process

The ATLAS and CMS experiments at CERN announce new results which show that the Higgs boson decays into two muons. These new results have pivotal importance for fundamental physics because they indicate for the first time that the Higgs boson interacts with second-generation elementary particles.

Press Statement | 03 Aug 2020

New ATLAS result marks milestone in the test of Standard Model properties

The ATLAS Collaboration has released a new study into a key building block of matter: leptons. This type of particle comes in three different families (flavours) and, according to the Standard Model, should follow strict rules. For instance, except for their mass, leptons of different flavours have identical properties – a feature known as lepton flavour universality. This was recently corroborated by a key measurement of the W-boson decay rates into leptons by the ATLAS Collaboration.

Physics Briefing | 03 Aug 2020

New measurements of the Higgs boson find strength in unity

Physicists can study Higgs-boson couplings in several ways: by measuring the rates of different Higgs boson production mechanisms and decays, and also by studying the particle’s kinematic properties. The ATLAS Collaboration has just presented precise new measurements of these key quantities. Several of these measurements were updated to use the full LHC Run 2 dataset (2015–2018), to provide the best precision to date.

Physics Briefing | 31 Jul 2020

Looking forward: ATLAS measures proton scattering when light turns into matter

Today, at the International Conference for High Energy Physics (ICHEP 2020), the ATLAS Collaboration announced first results using the ATLAS Forward Proton (AFP) spectrometer. With this instrument, physicists directly observed and measured the long sought-after prediction of proton scattering when particles of light turn into matter.

Physics Briefing | 30 Jul 2020

ATLAS probes interactions between heavyweights of the Standard Model

In the contest for the heaviest known elementary particle, the top quark and Z boson rank first and third, respectively. When a proton–proton collision produces a top-quark pair together with a Z boson – a process known as ttZ production – their total mass can reach an impressive 440 GeV! The discovery of this highly energetic process thus required the record collision energy and rate of the LHC; no previous collider could come close.

Physics Briefing | 30 Jul 2020

Jetting into the dark side: a precision search for dark matter

The nature of dark matter remains one of the great unsolved puzzles of fundamental physics. Many theoretical scenarios postulate that dark matter particles could be produced in the intense high-energy proton–proton collisions of the LHC. While the dark matter would escape the ATLAS detector unseen, it could occasionally be accompanied by a visible jet of particles radiated from the interaction point. Today, at the International Conference in High-Energy Physics (ICHEP 2020), ATLAS presented a new search for novel phenomena in collision events with jets and high missing transverse momentum (MET).

Physics Briefing | 27 Jul 2020

Summary of new ATLAS results for ICHEP 2020

Since the 1950s, one conference has stayed circled in red on every physicist's calendar: the International Conference on High­-Energy Physics (ICHEP). The fortieth edition of ICHEP kicks off today, bringing together particle physicists, astrophysicists and accelerator scientists to share the latest news in their fields. Originally planned as an in-person event in Prague, ICHEP2020 will instead be the very first all-virtual edition of the conference.

News | 27 Jul 2020

ATLAS one step closer in the search for rare Higgs boson decays to muons

The ATLAS Collaboration has released a new paper on the search for the Higgs-boson decay to a pair of muons. The new study uses the entire dataset collected by the ATLAS experiment during Run 2 of the LHC (2015–2018) to give a first hint of this elusive process.

Physics Briefing | 23 Jul 2020

Summary of ATLAS results presented at BOOST 2020

The first all-virtual BOOST workshop kicks off today, bringing together experts from the LHC experiments and the theory community. This is the twelfth conference on "Boosted Object Phenomenology, Reconstruction and Searches in High-Energy Physics" (BOOST 2020), hosting plenary-style talks and virtual poster presentations on the latest developments in hadronic physics.

News | 20 Jul 2020