V. Ananiev
A5066123467- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Particle Detector Development and Performance
- Quantum Chromodynamics and Particle Interactions
- Dark Matter and Cosmic Phenomena
- Computational Physics and Python Applications
- Neutrino Physics Research
- Cosmology and Gravitation Theories
- Distributed and Parallel Computing Systems
- Radiation Detection and Scintillator Technologies
- Medical Imaging Techniques and Applications
- Atomic and Subatomic Physics Research
- Neural Networks and Applications
- Advanced Data Storage Technologies
- Astrophysics and Cosmic Phenomena
- Gaussian Processes and Bayesian Inference
- Advanced Data Processing Techniques
- Big Data Technologies and Applications
- Nuclear Physics and Applications
- Superconducting Materials and Applications
- Advanced X-ray and CT Imaging
- Aquaculture Nutrition and Growth
- Black Holes and Theoretical Physics
- Nuclear reactor physics and engineering
- Marine Bivalve and Aquaculture Studies
University of Oslo
2022-2025
Brandeis University
2023-2024
Instituto de Física Corpuscular
2023-2024
Universitat de València
2023-2024
A. Alikhanyan National Laboratory
2024
SR Research (Canada)
2024
Federación Española de Enfermedades Raras
2024
Atlas Scientific (United States)
2024
BioMar (Norway)
2024
The University of Adelaide
2022-2023
Abstract The standard model of particle physics 1–4 describes the known fundamental particles and forces that make up our Universe, with exception gravity. One central features is a field permeates all space interacts 5–9 . quantum excitation this field, as Higgs manifests itself boson, only no spin. In 2012, properties consistent boson was observed by ATLAS CMS experiments at Large Hadron Collider CERN 10,11 Since then, more than 30 times many bosons have been recorded experiment, enabling...
Abstract The ATLAS experiment at the Large Hadron Collider has a broad physics programme ranging from precision measurements to direct searches for new particles and interactions, requiring ever larger more accurate datasets of simulated Monte Carlo events. Detector simulation with Geant4 is but requires significant CPU resources. Over past decade, developed utilized tools that replace most CPU-intensive component simulation—the calorimeter shower simulation—with faster methods. Here,...
The flavour-tagging algorithms developed by the ATLAS Collaboration and used to analyse its dataset of $\sqrt s = 13$ TeV $pp$ collisions from Run 2 Large Hadron Collider are presented. These new tagging based on recurrent deep neural networks, their performance is evaluated in simulated collision events. developments yield considerable improvements over previous jet-flavour identification strategies. At 77% $b$-jet efficiency operating point, light-jet (charm-jet) rejection factors 170 (5)...
Many extensions of the Standard Model predict production dark matter particles at LHC. Sufficiently light may be produced in decays Higgs boson that would appear invisible to detector. This Letter presents a statistical combination searches for H $\rightarrow$ where multiple modes are considered. These performed with ATLAS detector using 139 fb$^{-1}$ proton-proton collisions centre-of-mass energy $\sqrt{s} =13$ TeV In results =7$ and 8 TeV, an upper limit on branching ratio 0.107 (0.077)...
The first evidence for the Higgs boson decay to a <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>Z</a:mi></a:math> and photon is presented, with statistical significance of 3.4 standard deviations. result derived from combined analysis searches performed by ATLAS CMS Collaborations proton-proton collision datasets collected at CERN Large Hadron Collider (LHC) 2015 2018. These correspond integrated luminosities around <c:math...
Abstract The need for large-scale production of highly accurate simulated event samples the extensive physics programme ATLAS experiment at Large Hadron Collider motivates development new simulation techniques. Building on recent success deep learning algorithms, variational autoencoders and generative adversarial networks are investigated modelling response central region electromagnetic calorimeter to photons various energies. properties synthesised showers compared with from a full...
Abstract The ATLAS detector is installed in its experimental cavern at Point 1 of the CERN Large Hadron Collider. During Run 2 LHC, a luminosity ℒ = × 10 34 cm -2 s -1 was routinely achieved start fills, twice design luminosity. For 3, accelerator improvements, notably levelling, allow sustained running an instantaneous , with average up to 60 interactions per bunch crossing. has been upgraded recover single-lepton trigger thresholds while operating comfortably under 3 pileup conditions. A...
A bstract direct search for Higgs bosons produced via vector-boson fusion and subsequently decaying into invisible particles is reported. The analysis uses 139 fb − 1 of pp collision data at a centre-of-mass energy $$ \sqrt{s} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math> = 13 TeV recorded by the ATLAS detector LHC. observed numbers events are found to be in agreement with background expectation from Standard Model...
Abstract A technique is presented to measure the efficiency with which c -jets are mistagged as b (mistagging efficiency) using $$t\bar{t}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>t</mml:mi> <mml:mover> </mml:mrow> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> events, where one of W bosons decays into an electron or muon and a neutrino other quark–antiquark pair. The measurement utilises relatively large known $$W\rightarrow cs$$ <mml:mi>W</mml:mi>...
A search for the Higgs boson decaying into a pair of charm quarks is presented. The analysis uses proton-proton collisions to target production in association with leptonically $W$ or $Z$ boson. dataset delivered by LHC at centre-of-mass energy $\sqrt{s}=13$ TeV and recorded ATLAS detector corresponds an integrated luminosity 139 fb$^{-1}$. Flavour-tagging algorithms are used identify jets originating from hadronisation quarks. method validated simultaneous measurement $WW,WZ$ $ZZ$...
This paper presents the observation of four-top-quark ($t\bar{t}t\bar{t}$) production in proton-proton collisions at LHC. The analysis is performed using an integrated luminosity 140 fb$^{-1}$ a centre-of-mass energy 13 TeV collected ATLAS detector. Events containing two leptons with same electric charge or least three (electrons muons) are selected. Event kinematics used to separate signal from background through multivariate discriminant, and dedicated control regions constrain dominant...
Constraints on the Higgs boson self-coupling are set by combining double-Higgs analyses in bb¯bb¯, bb¯τ+τ− and bb¯γγ decay channels with single-Higgs targeting γγ, ZZ⁎, WW⁎, τ+τ− bb¯ channels. The data used these were recorded ATLAS detector at LHC proton–proton collisions s=13 TeV correspond to an integrated luminosity of 126–139 fb−1. combination sets upper limit μHH<2.4 95% confidence level production cross-section normalised its Standard Model prediction. Combining analyses, assumption...
A search for the electroweak production of pairs charged sleptons or charginos decaying into two-lepton final states with missing transverse momentum is presented. Two simplified models $R$-parity-conserving supersymmetry are considered: direct pair-production ($\tilde{\ell}\tilde{\ell}$), each a lepton and $\tilde{\chi}_1^0$ neutralino, lightest $(\tilde{\chi}_1^\pm\tilde{\chi}_1^\mp)$, $W$-boson $\tilde{\chi}_1^0$. The neutralino ($\tilde{\chi}_1^0$) assumed to be supersymmetric particle...
Abstract Searches for new phenomena inspired by supersymmetry in final states containing an $$e^+e^-$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mi>e</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:mo>-</mml:mo> </mml:mrow> </mml:math> or $$\mu ^+\mu ^-$$ <mml:mi>μ</mml:mi> pair, jets, and missing transverse momentum are presented. These searches make use of proton–proton collision data with integrated luminosity $$139~\text {fb}^{-1}$$...
The identification of $b$-jets, referred to as $b$-tagging, is an important part many physics analyses in the ATLAS experiment at Large Hadron Collider and accurate calibration its performance essential for high-quality results. This publication describes light-flavour jet mistagging efficiency a data sample proton-proton collision events $\sqrt{s}=13$ TeV corresponding integrated luminosity 139 fb$^{-1}$. performed $Z$ bosons produced association with jets. Due low jets, method which uses...
A search for nonresonant Higgs boson pair production in the $b\overline{b}b\overline{b}$ final state is presented. The analysis uses $126\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of $pp$ collision data at $\sqrt{s}=13\text{ }\mathrm{TeV}$ collected with ATLAS detector Large Hadron Collider, and targets both gluon-gluon fusion vector-boson modes. No evidence signal found observed (expected) upper limit on cross section determined to be 5.4 (8.1) times Standard Model predicted 95%...
In a special run of the LHC with $\beta^\star = 2.5~$km, proton-proton elastic-scattering events were recorded at $\sqrt{s} 13~$TeV an integrated luminosity $340~\mu \textrm{b}^{-1}$ using ALFA subdetector ATLAS in 2016. The elastic cross section was measured differentially Mandelstam $t$ variable range from $-t 2.5 \cdot 10^{-4}~$GeV$^{2}$ to 0.46~$GeV$^{2}$ 6.9 million candidates. This paper presents measurements total $\sigma_{\textrm{tot}}$, parameters nuclear slope, and $\rho$-parameter...
A search is made for potential ccc¯c¯ tetraquarks decaying into a pair of charmonium states in the four muon final state using proton-proton collision data at s=13 TeV, corresponding to an integrated luminosity 140 fb−1 recorded by ATLAS experiment LHC. Two decay channels, J/ψ+J/ψ→4μ and J/ψ+ψ(2S)→4μ, are studied. Backgrounds estimated based on hybrid approach involving Monte Carlo simulations data-driven methods. Statistically significant excesses with respect backgrounds dominated single...
A bstract search for Higgs boson pair production in events with two b -jets and τ -leptons is presented, using a proton–proton collision dataset an integrated luminosity of 139 fb − 1 collected at $$ \sqrt{s} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math> = 13 TeV by the ATLAS experiment LHC. pairs produced non-resonantly or decay narrow scalar resonance mass range from 251 to 1600 GeV are targeted. Events which least one...
Differential and double-differential distributions of kinematic variables leptons from decays top-quark pairs ($t\bar{t}$) are measured using the full LHC Run 2 data sample collected with ATLAS detector. The were at a $pp$ collision energy $\sqrt{s}=13$ TeV correspond to an integrated luminosity 140 fb$^{-1}$. measurements use events containing oppositely charged $e\mu$ pair $b$-tagged jets. results compared predictions several Monte Carlo generators. While no prediction is found be...
A search is made for potential ccc[over ¯]c[over ¯] tetraquarks decaying into a pair of charmonium states in the four muon final state using proton-proton collision data at sqrt[s]=13 TeV, corresponding to an integrated luminosity 140 fb^{-1} recorded by ATLAS experiment LHC. Two decay channels, J/ψ+J/ψ→4μ and J/ψ+ψ(2S)→4μ, are studied. Backgrounds estimated based on hybrid approach involving Monte Carlo simulations data-driven methods. Statistically significant excesses with respect...
A search for a long-lived, heavy neutral lepton (N) in 139 fb^{-1} of sqrt[s]=13 TeV pp collision data collected by the ATLAS detector at Large Hadron Collider is reported. The N produced via W→Nμ or W→Ne and decays into two charged leptons neutrino, forming displaced vertex. mass used to discriminate between signal background. No observed, limits are set on squared mixing parameters with left-handed neutrino states range 3 GeV<m_{N}<15 GeV. For first time, given both single-flavor...
Abstract A search for pair production of doubly charged Higgs bosons ( $$H^{\pm \pm }$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>H</mml:mi> <mml:mrow> <mml:mo>±</mml:mo> </mml:mrow> </mml:msup> </mml:math> ), each decaying into a prompt, isolated, and highly energetic leptons with the same electric charge, is presented. The uses proton–proton collision data sample at centre-of-mass energy 13 TeV corresponding to an integrated luminosity 139 fb $$^{-1}$$...
Abstract This paper presents the muon momentum calibration and performance studies for ATLAS detector based on pp collisions data sample produced at $$\sqrt{s}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math> = 13 TeV LHC during Run 2 corresponding to an integrated luminosity of 139 $${\textrm{fb}}^{-1}$$ <mml:msup> <mml:mrow> <mml:mtext>fb</mml:mtext> </mml:mrow> <mml:mo>-</mml:mo> <mml:mn>1</mml:mn> </mml:msup> . An...
Searches for new resonances are performed using an unsupervised anomaly-detection technique. Events with at least one electron or muon selected from <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mn>140</a:mn><a:mtext> </a:mtext><a:mtext> </a:mtext><a:msup><a:mrow><a:mi>fb</a:mi></a:mrow><a:mrow><a:mo>−</a:mo><a:mn>1</a:mn></a:mrow></a:msup></a:mrow></a:math> of <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"...