Briefings

Decoding top quarks: Precision in heavy-flavour partner production

Two new studies from the ATLAS Collaboration explore how top-quark pairs are produced alongside heavy-flavour quarks, like bottom and charm.

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Unveiling Higgs-boson production properties using tau-lepton pairs

New measurements by the ATLAS Collaboration show that studying Higgs-boson decays into tau-lepton pairs can reveal not only its interactions with fermions, but also give insights into Higgs-boson production at the LHC. ATLAS researchers performed two kinds of cross-section measurements in their new analysis of Higgs-boson decays to tau leptons.

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Transforming bottom-jets: machine learning for improved bottom-jets measurements

At the BOOST 2024 conference, the ATLAS Collaboration presented a new technique that employs artificial intelligence (AI) to refine jet calibration, specifically focusing on jets originating from bottom quarks (b-jets).

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Breaking through (jet) barriers

As the most abundantly produced object in the ATLAS experiment, jets are critical to understanding a number of physics processes. In new results presented at the BOOST 24 conference in Genova (Italy), ATLAS scientists detailed two innovative approaches for more accurately quantifying jet properties.

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Breaking “R-parity” in new searches for supersymmetry

At the recent ICHEP 2024 conference held in Prague (Czech Republic), ATLAS physicists presented two innovative searches for R-parity-violating SUSY using data collected during the Run 2 of the LHC (2015 to 2018).

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ATLAS releases precise new measurement of Higgs boson production in association with top quarks

At the recent International Conference on High-Energy Physics (ICHEP) 2024, the ATLAS Collaboration presented a new measurement of the ttH(bb) process using the same Run-2 dataset, achieving a factor of two better expected ttH signal significance compared to the previous result.

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The beauty and the charm of the Higgs boson

The ATLAS Collaboration has just released the world’s most precise study of the Higgs boson’s interaction with bottom quarks and charm quarks. This new result is a re-analysis of data collected during Run 2 of the LHC (2015-2018). ATLAS researchers examined Higgs-boson decays to bottom and charm quarks (H→bb and H→cc) implementing significantly improved analysis techniques.

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ATLAS probes uncharted territory with improved trigger

The ATLAS Collaboration has released its first search for new physics phenomena at the highest-ever collision energy of 13.6 TeV, targeting exotic events with two “displaced” leptons.

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Hunting for magnetic monopoles with the Universe's strongest magnetic fields

In a new result from the ATLAS Collaboration, physicists analysed the first Run-3 heavy-ion collision data collected in the autumn of 2023. Specifically researchers looked at “ultraperipheral” collisions, where ions pass at a distance precluding hadronic interactions yet close enough to interact through electromagnetic fields.

Physics Briefing |

Jetting into a new era of Higgs studies

The ATLAS Collaboration has made a significant advancement in the understanding of the Higgs boson by investigating its production in association with W or Z bosons (known as “VH production”), where the Higgs boson decays to bottom quarks. For the first time, LHC researchers have studied VH production in a fully hadronic final state.

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ATLAS searches for the building blocks of dark matter

Researchers at the ATLAS Experiment release the first-ever direct search for new composite dark particles called dark mesons, presented this week at the Large Hadron Collider Physics (LHCP) Conference in Boston.

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ATLAS chases long-lived particles with the Higgs boson

In a new study submitted to Physical Review Letters, ATLAS scientists used a new algorithm to search for long-lived particles (LLP) produced in the decay of Higgs bosons. These LLPs may leave a distinct signature of one or more hadronic “jets” of particles originating at a significantly displaced position from the proton–proton collision point.

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Looking for the extended family of the Higgs boson

The ATLAS Collaboration has just published a search for two new Higgs bosons, X and S, that would interact with the Standard-Model Higgs boson.

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Menu of the day: Di-Higgs soup!

If spotting one Higgs boson is interesting, what happens when you spot two? ATLAS researchers are looking for the production of two Higgs bosons using a new technique.

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ATLAS explores Z boson production with heavy-flavour quarks

Using the full LHC Run-2 dataset, the ATLAS Collaboration measured Z boson production in association with both bottom (b) and charm (c) quarks, the latter for the first time in ATLAS.

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ATLAS detects electrons and photons with greater clarity

New results released by the ATLAS Collaboration describe the significant advancements made in identifying electrons and photons.

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ATLAS provides first measurement of the W-boson width at the LHC

In a groundbreaking new result, the ATLAS Collaboration has measured the W-boson width for the first time at the Large Hadron Collider (LHC).

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First ATLAS measurement of W and Z boson production using Run-3 data

The ATLAS Collaboration has just released its first measurements using LHC Run-3 data of the production rates (“cross sections”) of W and Z bosons.

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Measuring the delicate balance of lepton flavours

In a new result presented at Moriond EW, physicists at the ATLAS Collaboration tested lepton flavour universality between muons and electrons. The precision of the result stands as the best yet-achieved in W-boson decays by a single experiment and surpasses the world average.

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ATLAS searches for new particles in familiar decays

In a new result, researchers conducted a novel search of data collected during Run 2 of the LHC, searching for heavy new particles that could fit the 2HDM or 2HDM+S models.

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ATLAS measures rare Higgs boson interaction with tau leptons

In a new result, the ATLAS Collaboration reports the first evidence of a Higgs boson produced in association with a leptonically-decaying W or Z boson and decaying into a pair of tau leptons.

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Searching for supersymmetric needles in the LHC haystack

The ATLAS Collaboration has published three new results in this challenging area, using Boosted Decision Trees (BDTs) to isolate potential signals and ultimately set stringent constraints on the masses of SUSY particles.

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ATLAS gains momentum in study of charmonium

The ATLAS Collaboration has measured the production cross section of the J/ψ and ψ(2S) charmonium states in terms of the transverse momentum and the rapidity. For both states, they examined the widest range of transverse momentum so far, thus providing new input for theoretical models.

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ATLAS and CMS unite to weigh in on the top quark

The ATLAS and CMS Experiments at CERN have just released a new measurement of the mass of the top quark. The new result combines 15 previous measurements to give the most precise determination of the top-quark mass to date.

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ATLAS achieves highest-energy detection of quantum entanglement

In a new result from the ATLAS Collaboration, physicists observed – for the first time – quantum entanglement between a pair of quarks. This is the highest-energy measurement of entanglement to date.

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