Briefings
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).
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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).
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.
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.
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.
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.
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.
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.
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.
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.
Shedding light on Higgs-boson self-interactions
The ATLAS Collaboration has released two brand-new results searching for di-Higgs events in the full LHC Run-2 dataset. In one, researchers looked for events where one Higgs boson decays into two bottom quarks and the other decays into two photons. In the other, they looked for events where one Higgs boson decays into two bottom quarks, and the other into two tau leptons or W/Z bosons, which subsequently decay into leptons.
ATLAS observes top quarks in proton-lead collisions
The ATLAS Collaboration at CERN observes the production of top-quark pairs in proton-lead ion collisions. ATLAS’ new result confirms and builds upon an earlier observation made by the CMS Collaboration, expanding it into a new decay channel.
When jets go dark
For the very first time, the ATLAS Collaboration has searched for dark jets that closely resemble QCD jets. Instead of originating from Standard-Model particles, these dark jets would be produced through a new, heavy particle called the Z' boson.
ATLAS measures ZZ production using Run-3 data and a new slim data format
The ATLAS Collaboration has just released a new measurement of the production cross section of two Z bosons. This highlight result examines data collected during Run 3 of the LHC and pioneers the use of PHYSLITE, a new, reduced data format that requires significantly less storage.