Search results for "Jets [Galaxies]"

Approches polydisciplinaires et projets internationaux en intelligence territoriale

2012

National audience

Measurement of ψ(2S) production as a function of charged-particle pseudorapidity density in pp collisions at √s = 13 TeV and p–Pb collisions at √sNN …

2023

Production of inclusive charmonia in pp collisions at center-of-mass energy of √ s = 13 TeV and p–Pb collisions at center-of-mass energy per nucleon pair of √ sNN = 8.16 TeV is studied as a function of charged-particle pseudorapidity density with ALICE. Ground and excited charmonium states (J/ψ, ψ(2S)) are measured from their dimuon decays in the interval of rapidity in the center-of-mass frame 2.5 < ycms < 4.0 for pp collisions, and 2.03 < ycms < 3.53 and −4.46 < ycms < −2.96 for p–Pb collisions. The charged-particle pseudorapidity density is measured around midrapidity (|η| < 1.0). In pp collisions, the measured charged-particle multiplicity extends to about six times the average value, w…

Measurements of the groomed jet radius and momentum splitting fraction with the soft drop and dynamical grooming algorithms in pp collisions at √s = …

2023

This article presents measurements of the groomed jet radius and momentum splitting fraction in pp collisions at √ s = 5.02 TeV with the ALICE detector at the Large Hadron Collider. Inclusive charged-particle jets are reconstructed at midrapidity using the anti-kT algorithm for transverse momentum 60< 80 GeV/c. We report results using two different grooming algorithms: soft drop and, for the first time, dynamical grooming. For each grooming algorithm, a variety of grooming settings are used in order to explore the impact of collinear radiation on these jet substructure observables. These results are compared to perturbative calculations that include resummation of large logarithms at all or…

Measurement of inclusive and leading subjet fragmentation in pp and Pb–Pb collisions at √sNN = 5.02 TeV

2023

This article presents new measurements of the fragmentation properties of jets in both proton–proton (pp) and heavy-ion collisions with the ALICE experiment at the Large Hadron Collider (LHC). We report distributions of the fraction zr of transverse momentum carried by subjets of radius r within jets of radius R. Charged-particle jets are reconstructed at midrapidity using the anti-kT algorithm with jet radius R = 0.4, and subjets are reconstructed by reclustering the jet constituents using the anti-kT algorithm with radii r = 0.1 and r = 0.2. In proton–proton collisions, we measure both the inclusive and leading subjet distributions. We compare these measurements to perturbative calculatio…

Dielectron production at midrapidity at low transverse momentum in peripheral and semi-peripheral Pb–Pb collisions at √sNN = 5.02 TeV

2023

Jet fragmentation transverse momentum distributions in pp and p-Pb collisions at √s, √sNN = 5.02 TeV

2021

Jet fragmentation transverse momentum (jT) distributions are measured in proton-proton (pp) and proton-lead (p-Pb) collisions at √sNN = 5.02 TeV with the ALICE experiment at the LHC. Jets are reconstructed with the ALICE tracking detectors and electromagnetic calorimeter using the anti-kT algorithm with resolution parameter R = 0.4 in the pseudorapidity range |η| < 0.25. The jT values are calculated for charged particles inside a fixed cone with a radius R = 0.4 around the reconstructed jet axis. The measured jT distributions are compared with a variety of parton-shower models. Herwig and Pythia 8 based models describe the data well for the higher jT region, while they underestimate the low…

Fast changes in the morphology of the X-ray emitting shocks in HH 154

2006

Our recent second epoch Chandra observations have shown a fast morphological evolution of the X-ray source associated with the protostellar jet HH 154 (Fig.\ 1). We propose to study the evolution of the optical structures in the jet, specially the ones associated with the X-ray emission with a monitoring program of imaging narrow and broad band optical observations. We will determine the proper motions (and braking) of the optical knows associated with shock features and the evolution of their line luminosity and therefore their cooling time. These data, together with our past and future X-ray observations, constitute a fundamental input and constraint to our parallel program of ongoing hyd…

Spilling the beans: The development of conceptual knowledge about food and its links with food rejection in young children (3-7-years-old)

2021

Insufficient dietary variety in children leads to significant nutrient deficiencies and health issues, both in childhood and later life (DeCosta et al., 2017). Cognitive mechanisms, such as categorization and conceptual knowledge, play an important role in understanding and appropriately accepting or rejecting foods (Mura Paroche et al., 2017). The food domain lends itself to many concepts and categories, such as taxonomic (i.e., lamb is meat), thematic (i.e., lamb goes on a plate), or script (i.e., lamb is eaten at dinner). Such knowledge aids accurate recognition, understanding, and appropriate interaction when confronted with foods situated in context. If conceptual knowledge is underdev…