Thread by @ATLASexperiment

The ATLAS Collaboration at @CERN is celebrating the results of 1,000 papers studying LHC collisions.

From the discovery of the Higgs boson to searches for new physics, these results give unprecedented insight into our Universe. Let's explore! THREAD⤵️ atlas.cern/updates/news/1…

In 2010, just 3 weeks into the first heavy-ion run, ATLAS saw an unexpectedly large imbalance of energy in pairs of particle jets created in lead-nuclei collisions. 🎇

This was the first observation of the "jet quenching" phenomenon at the LHC! cerncourier.com/a/atlas-observ…

Shortly afterwards, ATLAS scientists made the first measurement of top-quark pair production at the LHC.

This incredibly accurate result required just a few months worth of LHC data, demonstrating the extraordinary potential of the accelerator!

In a first-of-its-kind search, ATLAS researchers looked for new phenomena that fit "anomaly-mediated #Supersymmetry breaking" scenarios.

What this meant in practice: they had to develop new ways to find particles that leave disappearing tracks in the detector!

The hunt for #Supersymmetry reached new limits in 2014, as an ATLAS search for supersymmetric top quarks ruled out a number of "Natural Supersymmetry" theories.🧐 atlas.cern/updates/briefi…

The LHC has also proven to be a formidable tool for probing #DarkMatter. In 2015, ATLAS looked to shed light on the nature of this mysterious substance, studying its possible production in association with a single jet of particles. atlas.cern/updates/briefi…

Following their discovery of the #Higgsboson in 2012, physicists set out to study its properties in detail.

In 2016, ATLAS & CMS joined forces to give a precise experimental profile of the Higgs. Their combined result gave the most precise measurements of Higgs-boson couplings.

That same year, the ATLAS detector was put to the test in reconstructing electrons and muons almost to the TeV range!🎇

This allowed for greater exploration of the energy frontier, as scientists searched for new particles in collisions with the highest possible di-lepton masses.

While the search for new physics continued, there was still plenty to study in the Standard Model.

In 2017, ATLAS released a precise (0.2 per-mil relative uncertainty) measurement of the W-boson mass – a first for the #LHC!

The #Higgsboson re-entered the spotlight in 2018, as ATLAS & CMS announced the observation of a Higgs boson produced together with a top-quark pair!

This rare process is one of the most sensitive tests of the Brout-Englert-Higgs mechanism.

Among the rarest processes probed at the LHC is the scattering between the W and Z bosons, known as "vector boson scattering".

It was finally observed by ATLAS physicists in 2018 - opening a new chapter of Standard Model exploration at the LHC. atlas.cern/updates/briefi…

ATLAS surprised the scientific community in 2019, announcing the observation of high-energy light-by-light scattering. 💡💡

This is a very rare process in which two photons – particles of light – interact and change direction.

In 2020, ATLAS successfully measured the tiny CP-violation phase ϕs in the decay of a strange B hadron – a parameter very sensitive to new physics phenomena.

Key to this success: the enhanced sensitivity of the Insertable B-Layer sub-detector!

While reaching this milestone number of papers is worth celebrating, it is the work behind these publications that deserves the spotlight! Each represents a step forward in our understanding of the Universe.

➡️Explore more ATLAS highlights: cern.ch/go/H6g8

Look forward to another thousand steps over the decade to come, as the ATLAS Collaboration continues their exploration with the LHC, and prepares for its high-intensity second phase: the High-Luminosity LHC! [FIN]