5,844 research outputs found
âIntroduction. ÂŤLâingĂŠnieur dans tous ses ĂŠtatsÂť: lâessor dâun champ de recherche pluridisciplinaire et transnationalâ
En octobre 1980, se tenait Ă lâEcomusĂŠe du Creusot, ce haut lieu symbolique dâhistoire industrielle française, un colloque intitulĂŠ ÂŤ IngĂŠnieurs et sociĂŠtĂŠ Âť , une grande première dans le genre. RĂŠunie sur lâinitiative du directeur de lâEcomusĂŠe, Marcel Evrard, sous la prĂŠsidence de lâhistorien AndrĂŠ ThĂŠpot, une assemblĂŠe pluridisciplinaire dâexperts a ĂŠtĂŠ invitĂŠe Ă rĂŠflĂŠchir sur les origines et la nature du groupe professionnel des ingĂŠnieurs qui, malgrĂŠ le nombre de travaux les mentionnant, demeuraient, selon le constat collectif des experts, dâillustres inconnus de lâhistoire. Ainsi, les organisateurs ont-ils souhaitĂŠ dresser le bilan des travaux sur les ingĂŠnieurs menĂŠs jusquâalors ÂŤ en ordre dispersĂŠ Âť Ă lâoccasion et/ou dans le cadre dâĂŠtudes aux thĂŠmatiques historiques connexes ciblant un domaine des techniques, un secteur de lâindustrie, un champ de recherche scientifique, une aire gĂŠographique, une administration, une institution, une entreprise, une biographie dâexception, pour ne citer que les cadrages les plus frĂŠquents. En revanche, tout symbolique que fĂťt son rĂ´le dans lâindustrialisation aux XIXe et XXe siècles, le groupe professionnel des ingĂŠnieurs ne pouvait pas se prĂŠvaloir de rĂŠfĂŠrer son histoire ÂŤ Ă un domaine historique et sociologique constituĂŠ Âť : il demeurait donc très difficile Ă catĂŠgoriser . La dĂŠmarche a ĂŠtĂŠ sous-tendue par une prise de conscience importante, celle dâapprĂŠhender la perte de cohĂŠrence qui menaçait ce groupe professionnel sous lâimpact de lâĂŠclatement de plus en plus prononcĂŠ des domaines dâintervention, de la diversification des modes dâaction et des fonctions assimilĂŠes. DĂŠsenclaver les recherches sur les ingĂŠnieurs en tant que groupe professionnel et phĂŠnomène de sociĂŠtĂŠ, les sortir de leur confinement, leur imprimer une dynamique propre, â telle ĂŠtait lâambition des promoteurs du colloque. Et lâouvrage IngĂŠnieurs dans la sociĂŠtĂŠ française qui en est issu (1982), a posĂŠ les fondements dâun nouveau champ dâinvestigations, tant au point de vue des problĂŠmatiques que des approches mĂŠthodologiques..
The PDF4LHC report on PDFs and LHC data: Results from Run I and preparation for Run II
The accurate determination of the Parton Distribution Functions (PDFs) of the
proton is an essential ingredient of the Large Hadron Collider (LHC) program.
PDF uncertainties impact a wide range of processes, from Higgs boson
characterisation and precision Standard Model measurements to New Physics
searches. A major recent development in modern PDF analyses has been to exploit
the wealth of new information contained in precision measurements from the LHC
Run I, as well as progress in tools and methods to include these data in PDF
fits. In this report we summarise the information that PDF-sensitive
measurements at the LHC have provided so far, and review the prospects for
further constraining PDFs with data from the recently started Run II. This
document aims to provide useful input to the LHC collaborations to prioritise
their PDF-sensitive measurements at Run II, as well as a comprehensive
reference for the PDF-fitting collaborations.Comment: 55 pages, 13 figure
High rate, fast timing Glass RPC for the high {\eta} CMS muon detectors
The HL-LHC phase is designed to increase by an order of magnitude the amount
of data to be collected by the LHC experiments. To achieve this goal in a
reasonable time scale the instantaneous luminosity would also increase by an
order of magnitude up to . The region of the forward
muon spectrometer () is not equipped with RPC stations. The
increase of the expected particles rate up to (including a
safety factor 3) motivates the installation of RPC chambers to guarantee
redundancy with the CSC chambers already present. The actual RPC technology of
CMS cannot sustain the expected background level. The new technology that will
be chosen should have a high rate capability and provides a good spatial and
timing resolution. A new generation of Glass-RPC (GRPC) using low-resistivity
(LR) glass is proposed to equip at least the two most far away of the four high
muon stations of CMS. First the design of small size prototypes and
studies of their performance in high-rate particles flux is presented. Then the
proposed designs for large size chambers and their fast-timing electronic
readout are examined and preliminary results are provided.Comment: 14 pages, 11 figures, Conference proceeding for the 2016 Resistive
Plate Chambers and Related Detector
Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV
A search for new physics is presented based on an event signature of at least
three jets accompanied by large missing transverse momentum, using a data
sample corresponding to an integrated luminosity of 36 inverse picobarns
collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector
at the LHC. No excess of events is observed above the expected standard model
backgrounds, which are all estimated from the data. Exclusion limits are
presented for the constrained minimal supersymmetric extension of the standard
model. Cross section limits are also presented using simplified models with new
particles decaying to an undetected particle and one or two jets
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
X-ray emission from the Sombrero galaxy: discrete sources
We present a study of discrete X-ray sources in and around the
bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival
Chandra observations with a total exposure of ~200 ks. With a detection limit
of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30
kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler
et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS
observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray
binaries (LMXBs). We quantify the differential luminosity functions (LFs) for
both the detected GC and field LMXBs, whose power-low indices (~1.1 for the
GC-LF and ~1.6 for field-LF) are consistent with previous studies for
elliptical galaxies. With precise sky positions of the GCs without a detected
X-ray source, we further quantify, through a fluctuation analysis, the GC LF at
fainter luminosities down to 1E35 erg/s. The derived index rules out a
faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent
findings in several elliptical galaxies and the bulge of M31. On the other
hand, the 2-6 keV unresolved emission places a tight constraint on the field
LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101
sources in the halo of Sombrero. The presence of these sources cannot be
interpreted as galactic LMXBs whose spatial distribution empirically follows
the starlight. Their number is also higher than the expected number of cosmic
AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray
surveys. We suggest that either the cosmic X-ray background is unusually high
in the direction of Sombrero, or a distinct population of X-ray sources is
present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres
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