Search results for "jet [galaxies]"
showing 10 items of 1404 documents
Event-by-event picture for the medium-induced jet evolution
2016
We discuss the evolution of an energetic jet which propagates through a dense quark-gluon plasma and radiates gluons due to its interactions with the medium. Within perturbative QCD, this evolution can be described as a stochastic branching process, that we have managed to solve exactly. We present exact, analytic, results for the gluon spectrum (the average gluon distribution) and for the higher n-point functions, which describe correlations and fluctuations. Using these results, we construct the event-by-event picture of the gluon distribution produced via medium-induced gluon branching. In contrast to what happens in a usual QCD cascade in vacuum, the medium-induced branchings are quasi-…
Jet mass and substructure of inclusive jets in $ \sqrt {s} = 7\;{\text{TeV}} $ pp collisions with the ATLAS experiment
2012
Recent studies have highlighted the potential of jet substructure techniques to identify the hadronic decays of boosted heavy particles. These studies all rely upon the assumption that the internal substructure of jets generated by QCD radiation is well understood. In this article, this assumption is tested on an inclusive sample of jets recorded with the ATLAS detector in 2010, which corresponds to 35 pb-1 of pp collisions delivered by the LHC at √s = 7TeV. In a subsample of events with single pp collisions, measurements corrected for detector efficiency and resolution are presented with full systematic uncertainties. Jet invariant mass, kt splitting scales and N-subjettiness variables are…
Jet shape modification in Pb-Pb collisions at √S[sub]N[sub]N= 2.76 TeV using two-particle correlations
2018
This thesis focuses on two separate topics. The first topic concerns the upgrade of the Time Projection Chamber (TPC) detector of the ALICE experiment. The upgrade will take place during the second Long Shutdown (2019-2020). The part of the upgrade I participated in was the replacement of the detector’s current readout electronics with Gas Electron Multiplier (GEM) foils. This change would allow for the continuous readout of the data, resulting in a hundredfold increase in the amount of data the ALICE experiment can process, as the TPC is the central tracking detector. I was involved in the Quality Assurance (QA) of these GEM foils. The advanced QA procedure consists of three measurements, a…
Exploration of jet substructure using iterative declustering in pp and Pb–Pb collisions at LHC energies
2020
The ALICE collaboration at the CERN LHC reports novel measurements of jet substructure in pp collisions at $\sqrt{s}$= 7 TeV and central Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 2.76 TeV. Jet substructure of track-based jets is explored via iterative declustering and grooming techniques. We present the measurement of the momentum sharing of two-prong substructure exposed via grooming, the $z_{\rm{g}}$, and its dependence on the opening angle, in both pp and Pb-Pb collisions. We also present the first measurement of the distribution of the number of branches obtained in the iterative declustering of the jet, which is interpreted as the number of its hard splittings. In Pb-Pb collisions, we…
Search for pair production of first or second generation leptoquarks in proton-proton collisions at sqrt(s)=7 TeV using the ATLAS detector at the LHC
2011
This paper describes searches for the pair production of first or second generation scalar leptoquarks using 35 pb−1 of proton-proton collision data recorded by the ATLAS detector at √s=7 TeV. Leptoquarks are searched in events with two oppositely-charged muons or electrons and at least two jets, and in events with one muon or electron, missing transverse momentum and at least two jets. After event selection, the observed yields are consistent with the predicted backgrounds. Leptoquark production is excluded at the 95% CL for masses MLQ<376 (319) GeV and MLQ<422 (362) GeV for first and second generation scalar leptoquarks, respectively, when assuming the branching fraction of a leptoquark…
"Table 30" of "Measurements of $t\bar{t}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in $pp$ coll…
2018
$p_{T}^{t,1}$ correlation matrix for relative differential cross-section in particle level
"Table 28" of "Measurements of $t\bar{t}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in $pp$ coll…
2018
$p_{T}^{t,1}$ correlation matrix for absolute differential cross-section in particle level
"Table 29" of "Measurements of $t\bar{t}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in $pp$ coll…
2018
$p_{T}^{t,1}$ covariance matrix for relative differential cross-section in particle level
"Table 27" of "Measurements of $t\bar{t}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in $pp$ coll…
2018
$p_{T}^{t,1}$ covariance matrix for absolute differential cross-section in particle level
"Table 14" of "Measurements of $t\bar{t}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in $pp$ coll…
2019
$p_{T}^{t,1}$ relative differential cross-section in particle level