Publications by authors named "Canepa A"

The production rates of prompt and non-prompt [Formula: see text] and [Formula: see text] mesons in their dimuon decay modes are measured using 2.1 and 11.4 fb[Formula: see text] of data collected with the ATLAS experiment at the Large Hadron Collider, in proton-proton collisions at [Formula: see text] and 8 respectively.

View Article and Find Full Text PDF

A search for strongly produced supersymmetric particles is conducted using signatures involving multiple energetic jets and either two isolated leptons ( or [Formula: see text]) with the same electric charge or at least three isolated leptons. The search also utilises -tagged jets, missing transverse momentum and other observables to extend its sensitivity. The analysis uses a data sample of proton-proton collisions at [Formula: see text] TeV recorded with the ATLAS detector at the Large Hadron Collider in 2015 corresponding to a total integrated luminosity of 3.

View Article and Find Full Text PDF
Article Synopsis
  • * Key variables used for differentiation include jet mass, jet charge, and a \(\tau\)-tagging discriminant, leading to the development of a likelihood tagger for better identification.
  • * Although direct measurement of tagging efficiencies is not possible due to a lack of pure samples, the tagger's modeling with a sample enriched in \(W/Z\) events indicates strong predictive performance for future data processing.
View Article and Find Full Text PDF

This article presents the sensitivity of the ATLAS experiment to the lepton-flavour-violating decays of [Formula: see text]. A method utilising the production of [Formula: see text] leptons via [Formula: see text] decays is used. This method is applied to the sample of 20.

View Article and Find Full Text PDF

Results of a search for new phenomena in events with at least three photons are reported. Data from proton-proton collisions at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 20.3 fb[Formula: see text], were collected with the ATLAS detector at the LHC.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates how the number of charged particles produced in proton-lead collisions changes depending on how central the collision is, using data collected by the ATLAS detector at the Large Hadron Collider.
  • It focuses on measuring the mean charged-particle multiplicity across various pseudorapidity values and finds that the particle distribution demonstrates significant variation based on collision centrality, becoming more asymmetric as collisions become more central.
  • Three models are used to estimate the number of nucleons involved in the collision, revealing differing outcomes for charged-particle multiplicities, which emphasizes the need to consider color fluctuations in these interactions for more accurate modeling.
View Article and Find Full Text PDF

The jet energy scale (JES) and its systematic uncertainty are determined for jets measured with the ATLAS detector using proton-proton collision data with a centre-of-mass energy of [Formula: see text] TeV corresponding to an integrated luminosity of [Formula: see text][Formula: see text]. Jets are reconstructed from energy deposits forming topological clusters of calorimeter cells using the anti-[Formula: see text] algorithm with distance parameters [Formula: see text] or [Formula: see text], and are calibrated using MC simulations. A residual JES correction is applied to account for differences between data and MC simulations.

View Article and Find Full Text PDF

This paper reviews and extends searches for the direct pair production of the scalar supersymmetric partners of the top and bottom quarks in proton-proton collisions collected by the ATLAS collaboration during the LHC Run 1. Most of the analyses use 20 [Formula: see text] of collisions at a centre-of-mass energy of [Formula: see text] TeV, although in some case an additional [Formula: see text] of collision data at [Formula: see text] TeV are used. New analyses are introduced to improve the sensitivity to specific regions of the model parameter space.

View Article and Find Full Text PDF

Many extensions of the Standard Model predict the existence of charged heavy long-lived particles, such as -hadrons or charginos. These particles, if produced at the Large Hadron Collider, should be moving non-relativistically and are therefore identifiable through the measurement of an anomalously large specific energy loss in the ATLAS pixel detector. Measuring heavy long-lived particles through their track parameters in the vicinity of the interaction vertex provides sensitivity to metastable particles with lifetimes from 0.

View Article and Find Full Text PDF

Jellyfish outbreaks are increasingly viewed as a deterministic response to escalating levels of environmental degradation and climate extremes. However, a comprehensive understanding of the influence of deterministic drivers and stochastic environmental variations favouring population renewal processes has remained elusive. This study quantifies the deterministic and stochastic components of environmental change that lead to outbreaks of the jellyfish Pelagia noctiluca in the Mediterranen Sea.

View Article and Find Full Text PDF

Studies of the spin, parity and tensor couplings of the Higgs boson in the [Formula: see text], [Formula: see text] and [Formula: see text] decay processes at the LHC are presented. The investigations are based on [Formula: see text] of collision data collected by the ATLAS experiment at [Formula: see text] TeV and [Formula: see text] TeV. The Standard Model (SM) Higgs boson hypothesis, corresponding to the quantum numbers [Formula: see text], is tested against several alternative spin scenarios, including non-SM spin-0 and spin-2 models with universal and non-universal couplings to fermions and vector bosons.

View Article and Find Full Text PDF

The paper presents studies of Bose-Einstein Correlations (BEC) for pairs of like-sign charged particles measured in the kinematic range [Formula: see text] 100 MeV and [Formula: see text] 2.5 in proton collisions at centre-of-mass energies of 0.9 and 7 TeV with the ATLAS detector at the CERN Large Hadron Collider.

View Article and Find Full Text PDF

Results of a search for new phenomena in events with large missing transverse momentum and a Higgs boson decaying to two photons are reported. Data from proton-proton collisions at a center-of-mass energy of 8 TeV and corresponding to an integrated luminosity of 20.3 fb^{-1} have been collected with the ATLAS detector at the LHC.

View Article and Find Full Text PDF

A search for Higgs boson pair production [Formula: see text] is performed with 19.5 fb[Formula: see text] of proton-proton collision data at [Formula: see text] TeV, which were recorded by the ATLAS detector at the Large Hadron Collider in 2012. The decay products of each Higgs boson are reconstructed as a high-momentum [Formula: see text] system with either a pair of small-radius jets or a single large-radius jet, the latter exploiting jet substructure techniques and associated -tagged track-jets.

View Article and Find Full Text PDF

Frequently, population ecology of marine organisms uses a descriptive approach in which their sizes and densities are plotted over time. This approach has limited usefulness for design strategies in management or modelling different scenarios. Population projection matrix models are among the most widely used tools in ecology.

View Article and Find Full Text PDF

Measurements of the total and differential cross sections of Higgs boson production are performed using 20.3  fb^{-1} of pp collisions produced by the Large Hadron Collider at a center-of-mass energy of sqrt[s]=8  TeV and recorded by the ATLAS detector. Cross sections are obtained from measured H→γγ and H→ZZ^{*}→4ℓ event yields, which are combined accounting for detector efficiencies, fiducial acceptances, and branching fractions.

View Article and Find Full Text PDF

A search for heavy long-lived multi-charged particles is performed using the ATLAS detector at the LHC. Data collected in 2012 at [Formula: see text] TeV from collisions corresponding to an integrated luminosity of 20.3 fb[Formula: see text]are examined.

View Article and Find Full Text PDF

A search for the Standard Model Higgs boson produced in association with a top-quark pair, [Formula: see text], is presented. The analysis uses 20.3 fb of collision data at [Formula: see text], collected with the ATLAS detector at the Large Hadron Collider during 2012.

View Article and Find Full Text PDF

This Letter reports evidence of triple gauge boson production pp→W(ℓν)γγ+X, which is accessible for the first time with the 8 TeV LHC data set. The fiducial cross section for this process is measured in a data sample corresponding to an integrated luminosity of 20.3  fb^{-1}, collected by the ATLAS detector in 2012.

View Article and Find Full Text PDF

This Letter presents a search for a heavy neutral particle decaying into an opposite-sign different-flavor dilepton pair, e^{±}μ^{∓}, e^{±}τ^{∓}, or μ^{±}τ^{∓} using 20.3  fb^{-1} of pp collision data at sqrt[s]=8  TeV collected by the ATLAS detector at the LHC. The numbers of observed candidate events are compatible with the standard model expectations.

View Article and Find Full Text PDF

A search for Higgs boson decays to invisible particles is performed using 20.3 [Formula: see text] of collision data at a centre-of-mass energy of 8 TeV recorded by the ATLAS detector at the Large Hadron Collider. The process considered is Higgs boson production in association with a vector boson ([Formula: see text] or ) that decays hadronically, resulting in events with two or more jets and large missing transverse momentum.

View Article and Find Full Text PDF

Measurements of the and final states in the mass range above the [Formula: see text] and [Formula: see text] thresholds provide a unique opportunity to measure the off-shell coupling strength of the Higgs boson. This paper presents constraints on the off-shell Higgs boson event yields normalised to the Standard Model prediction (signal strength) in the [Formula: see text], [Formula: see text] and [Formula: see text] final states. The result is based on collision data collected by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 20.

View Article and Find Full Text PDF

A search for a charged Higgs boson, H(±), decaying to a W(±) boson and a Z boson is presented. The search is based on 20.3  fb(-1) of proton-proton collision data at a center-of-mass energy of 8 TeV recorded with the ATLAS detector at the LHC.

View Article and Find Full Text PDF

A search for new phenomena in LHC proton-proton collisions at a center-of-mass energy of sqrt[s]=8 TeV was performed with the ATLAS detector using an integrated luminosity of 17.3 fb^{-1}. The angular distributions are studied in events with at least two jets; the highest dijet mass observed is 5.

View Article and Find Full Text PDF