629 research outputs found
Early QCD measurements with ATLAS
No full textEarly QCD physics studies at the LHC using the ATLAS experiment are presented
ttbar resonance searches at the LHC
No full textResults of searches for heavy resonances decaying into ttbar pairs at the LHC using the ATLAS and CMS experiments are presented
A Study of the Reaction e+e- → mu+mu- Using the CELLO Detector
No full textA study was made of the reaction e+e- → mu+mu- using the CELLO detector at PETRA. Using data collected at a centre of mass energy of 35 GeV the total cross section, sigma0 and the electroweak charge asymmetry. Afb were measured giving: Rmumu =sigma0/sigmaQED = 0.95+/-0.02+/-0.05; Afb = -8.9+/-2.0+/-1.0 % The results are in good agreement with the values predicted by the electroweak model of Rmumu = 1.0 and Afb = -8.9% at this energy. Using data collected at a centre of mass energy of 43 GeV a search was made for acoplanar muon pairs, a signature of scalar muons. No candidates were found and the following masses were excluded at the 95% C. L
Measurement of jet substructure with the ATLAS detector
No full textMeasurements of the substructure of jets are presented using 140 fb-1 of proton-proton collisions with sqrt(s)=13 TeV center-of-mass energy recorded with the ATLAS detector at CERN Large Hadron Collider. Various results are presented including the measurement of non-perturbative track functions, or, the ratio of a jet transverse momentum carried by its charged constituents to its complete transverse momentum. The first differential cross-section measurement of Lund sub-jet multiplicities using dijet events and the measurement of the Lund Jet Plane in ttbar events are also shown in this contribution. Moreover, the measurements of the substructure of top-quark jets are presented using top quarks which are reconstructed with Antikt algorithm with a radius parameter R=1.0
Status of the ATLAS ITk Pixel Project
No full textIn the high-luminosity era of the Large Hadron Collider, the instantaneous luminosity is expected to reach unprecedented values, resulting in up to 200 proton-proton interactions in a typical bunch crossing. To cope with the resulting increase in occupancy, bandwidth and radiation damage, the ATLAS Inner Detector will be replaced by an all-silicon system, the Inner Tracker (ITk). The innermost part of the ITk will consist of a pixel detector, with an active area of about 13m^2. To deal with the changing requirements in terms of radiation hardness, power dissipation and production yield, several silicon sensor technologies equipped with novel ASICs connecting by bump-bonding technique will be employed in the five barrel and endcap layers. As a timeline, it is facing to pre-production of components, sensor, building modules, mechanical structures and services. This contribution presents the status of the ITk-pixel project focusing on the lessons learned and the biggest challenges towards production, from mechanics structures to sensors, and it will summarize the latest results on closest-to-real demonstrators built using module, electric and cooling services prototypes
ATLAS ITk Pixel Detector Overview
No full textIn the high-luminosity era of the Large Hadron Collider, the instantaneous luminosity is expected to reach unprecedented values, resulting in up to 200 proton-proton interactions in a typical bunch crossing. To cope with the resulting increase in occupancy, bandwidth and radiation damage, the ATLAS Inner Detector will be replaced by an all-silicon system, the Inner Tracker (ITk). The innermost part of the ITk will consist of a pixel detector, with an active area of about 13m. To deal with the changing requirements in terms of radiation hardness, power dissipation and production yield, several silicon sensor technologies equipped with novel ASICs connecting by bump-bonding technique will be employed in the five barrel and endcap layers. As a timeline, it is facing to pre-production of components, sensor, building modules, mechanical structures and services. This contribution presents the status of the ITk-pixel project focusing on the lessons learned and the biggest challenges towards production, from mechanics structures to sensors, and it will summarize the latest results on closest-to-real demonstrators built using module, electric and cooling services prototypes
ATLAS ITk pixel detector overview
No full textIn the high-luminosity era of the Large Hadron Collider, the instantaneous luminosity is expected to reach unprecedented values, resulting in up to 200 proton–proton interactions in a typical bunch crossing. To cope with the resulting increase in occupancy, bandwidth and radiation damage, the ATLAS Inner Detector will be replaced by an all-silicon system, the Inner Tracker (ITk). The innermost part of the ITk will consist of a pixel detector, with an active area of about 13 m2. To deal with the changing requirements in terms of radiation hardness, power dissipation and production yield, several silicon sensor technologies equipped with novel ASICs connecting by bump-bonding technique will be employed in the five barrel and endcap layers. As a timeline, it is facing to pre-production of components, sensor, building modules, mechanical structures and services. This contribution presents the status of the ITk-pixel project focusing on the lessons learned and the biggest challenges towards production, from mechanics structures to sensors, and it will summarise the latest results on closest-to-real demonstrators built using module, electric and cooling services prototypes
Testbeam analysis of biasing structures for irradiated hybrid pixel detectors
No full textJournal of Instrumentation
The International School for Advanced Studies (SISSA), find out more.
paper • The following article isOpen access
Testbeam analysis of biasing structures for irradiated hybrid pixel detectors
A.G. Rennie, C.M. Buttar, Y. Gao, R. González López, D. Maneuski, E. Pender, Q. Qin, M. Sullivan, J.T. Taylor and K. Wraight
Published 31 January 2025 • © 2025 The Author(s)
Journal of Instrumentation, Volume 20, January 2025
Citation A.G. Rennie et al 2025 JINST 20 P01029
DOI 10.1088/1748-0221/20/01/P01029
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Abstract
Following the Phase-II upgrade during Long Shutdown (LS3), the LHC aims to reach a peak instantaneous luminosity of 7.5× 1034 cm-2 s-1, which corresponds to an average of around 200 inelastic proton-proton collisions per beam-crossing (every 25 ns). To cope with these conditions, the ATLAS Inner Detector will be replaced by a new all-silicon system — the Inner Tracker (ITk). The ITk will be operational for more than ten years, during which time ATLAS is expected to record approximately 4000 fb-1 of data. The ITk's pixel sub-system is based on hybrid pixel modules with new silicon sensors and readout chips. These studies focus on testbeam campaigns undertaken to study the spatial resolution and efficiencies of hybrid pixel detector modules based on the first large-structure prototype front-end readout chip — the RD53A — using planar silicon sensors. These devices have been irradiated to replicate the effect of the high radiation environment present during operation in the ATLAS detector. Results for devices using sensors with different punch-through bias structures and using different readout modes are summarised. Those with sensors incorporating a punch-through bias structure are found to exhibit systematically lower efficiency than those without, as a result of local areas of relative inefficiency around the punch-through dots. Despite this, all devices measured are found to satisfy the requirement of 97% efficiency at Vbias = 400 V after being irradiated to end-of-life fluence
«Preferirebbe buttar via il nome». L’evasione dal principium individuationis del nome e dall’identità in ‘Rubè’ di Borgese
No full textThe paper highlights the remarkable pregnancy, in thematic, ideological, formal and
even structural terms, of names in Rubè (1921), a novel by Giuseppe Antonio Borgese, focusing on
the troublesome relationship that the main character Filippo Rubè establishes with them, leading
to an identity crisis. Capone identifies five modes of using names in Rubè: the escape from the principium
individuationis of the name as an ideological breakout from the chains of a fixed identity; the
intentional modifications of his name made by Rubè in order to avoid his registry and social identity
and, thus, to be able to escape from the duties of ordinary life; the change of the names of the women
loved by Filippo; some irreversible plot twists brought about by proper names; the inability to give
adequate names to blurred feelings. By the analysis of these uses, the author points out how many
times in Rubè not just nomina sunt consequentia rerum, but res sunt consequentia nominum as well
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