Publications database

The high-luminosity phase of LHC operations (HL-LHC), willfeature a large increase in simultaneous proton-proton interactionsper bunch crossing up to 200, compared with a typical levelingtarget of 64 in Run 3. Such an increase will create a verychallenging environment in which to perform charged particletrajectory reconstruction, a task crucial for the success of theATLAS physics program, and will exceed the capabilities of thecurrent ATLAS Inner Detector (ID). [...]

In 2022 and 2023, the Large Hadron Collider producedapproximately two billion hadronic interactions each second frombunches of protons that collide at a rate of 40 MHz. The ATLAStrigger system is used to reduce this rate to a few kHz forrecording. [...]

A measurement is presented of elliptic ($v_2$) and triangular ($v_3$) azimuthal anisotropy coefficients for charged particles produced in Pb+Pb collisions at $\sqrt{s_{_\text{NN}}} = 5.02$ TeV using a dataset corresponding to an integrated luminosity of $0.44$ nb$^{-1}$ collected with the ATLAS detector at the LHC in 2018. The values of $v_2$ and $v_3$ are measured for charged particles over a wide range of transverse momentum ($p_\text{T}$), 1-400 GeV, and Pb+Pb collision centrality, 0-60%, using the scalar product and multi-particle cumulant methods. [...]

A search for the production of three massive vector bosons, $VVZ (V=W, Z)$, in proton-proton collisions at $\sqrt{s} = 13$ TeV is performed using data with an integrated luminosity of $140$ fb$^{-1}$ recorded by the ATLAS detector at the Large Hadron Collider. Events produced in the leptonic final states $WWZ \to \ell\nu \ell\nu \ell \ell$ ($\ell=e, \mu$), $WZZ \to \ell\nu \ell\ell \ell\ell$, $ZZZ \to \ell\ell \ell\ell \ell\ell$, and the semileptonic final states $WWZ \to qq \ell\nu \ell \ell$ and $WZZ \to \ell\nu qq \ell \ell$, are analysed. [...]

The high-luminosity phase of LHC operations (HL-LHC), willfeature a large increase in simultaneous proton-proton interactionsper bunch crossing up to 200, compared with a typical levelingtarget of 64 in Run 3. Such an increase will create a verychallenging environment in which to perform charged particletrajectory reconstruction, a task crucial for the success of theATLAS physics program, and will exceed the capabilities of thecurrent ATLAS Inner Detector (ID). [...]

A search for exotic decays of the 125 GeV Higgs boson into a pair of new spin-0 particles, H → aa, where one decays into a photon pair and the other into a τ-lepton pair, is presented. Hadronic decays of the τ-leptons are considered and reconstructed using a dedicated tagger for collimated τ-lepton pairs [...]

A measurement of the ratio of the branching fractions, R$_{τ/e}$ = B(W → τν)/B(W → eν), is performed using a sample of W bosons originating from top-quark decays to final states containing τ-leptons or electrons. This measurement uses pp collisions at $ \sqrt{s} $ = 13 TeV, collected by the ATLAS experiment at the Large Hadron Collider during Run 2, corresponding to an integrated luminosity of 140 fb$^{−1}$ [...]

A measurement of off-shell Higgs boson production in the $H^*\to ZZ\to 4\ell$ decay channel is presented. The measurement uses 140 fb$^{−1}$ of proton–proton collisions at $\sqrt{s} = 13$ TeV collected by the ATLAS detector at the Large Hadron Collider and supersedes the previous result in this decay channel using the same dataset. [...]

Astrophysical observations provide compelling evidence for gravitationally interacting dark matter in the universe that cannot be explained by the standard model of particle physics. The extraordinary amount of data from the CERN LHC presents a unique opportunity to shed light on the nature of dark matter at unprecedented collision energies. [...]

Together with EuGa$_4$ and EuAl$_4$, EuAl$_2$⁢Ga$_2$ belongs to the BaAl$_4$ structure type with space group 𝐼⁢4/mmm. EuAl2⁢Ga2 develops an incommensurate charge density wave (CDW) at temperatures below $𝑇_{CDW}$=51K. [...]