Contribution française à l'upgrade de LHCb

La contribution française à l'upgrade de LHCb est d etaillée dans ce document et s'inscrit dans le prolongement du Framework TDR soumis au LHCC le 25 mai 2012. La France a contribué à la conception et à la réalisation de la mécanique et de l'électronique de lecture des calorimètres. Elle est l'acteur principal du système de déclenchement de premier niveau et l'initiatrice du projet DIRAC, progiciel de traitement et d'analyse de données dans un environnement distribué. Les physiciens et ingénieurs français ont de nombreuses responsabilités de premier plan et sont très fortement impliqués dans l'analyse des données. Les groupes français souhaitent poursuivre leur forte participation a l'expérience en contribuant a son upgrade, notamment l'électronique de lecture des calorimètres et du trajectographe en fibres scintillantes ainsi qu'au data processing

Contribution française à l'upgrade de LHCb

La contribution française à l'upgrade de LHCb est d etaillée dans ce document et s'inscrit dans le prolongement du Framework TDR soumis au LHCC le 25 mai 2012. La France a contribué à la conception et à la réalisation de la mécanique et de l'électronique de lecture des calorimètres. Elle est l'acteur principal du système de déclenchement de premier niveau et l'initiatrice du projet DIRAC, progiciel de traitement et d'analyse de données dans un environnement distribué. Les physiciens et ingénieurs français ont de nombreuses responsabilités de premier plan et sont très fortement impliqués dans l'analyse des données. Les groupes français souhaitent poursuivre leur forte participation a l'expérience en contribuant a son upgrade, notamment l'électronique de lecture des calorimètres et du trajectographe en fibres scintillantes ainsi qu'au data processing

Elliptic flow of charged particles in Pb-Pb collisions at 2.76 TeV

We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at 2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|$\eta$|<0.8) and transverse momentum range 0.2< $p_{\rm T}$< 5.0 GeV/$c$. The elliptic flow signal v$_2$, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 $\pm$ 0.002 (stat) $\pm$ 0.004 (syst) in the 40-50% centrality class. The differential elliptic flow v$_2(p_{\rm T})$ reaches a maximum of 0.2 near $p_{\rm T}$ = 3 GeV/$c$. Compared to RHIC Au-Au collisions at 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.Comment: 10 pages, 4 captioned figures, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/389

A uniform, quality controlled Surface Ocean CO2 Atlas (SOCAT)

A well documented, publicly available, global data set of surface ocean carbon dioxide (CO2) parameters has been called for by international groups for nearly two decades. The Surface Ocean CO2 Atlas (SOCAT) project was initiated by the international marine carbon science community in 2007 with the aim of providing a comprehensive, publicly available, regularly updated, global data set of marine surface CO2, which had been subject to quality control (QC). Many additional CO2 data, not yet made public via the Carbon Dioxide Information Analysis Center (CDIAC), were retrieved from data originators, public websites and other data centres. All data were put in a uniform format following a strict protocol. Quality control was carried out according to clearly defined criteria. Regional specialists performed the quality control, using state-of-the-art web-based tools, specially developed for accomplishing this global team effort. SOCAT version 1.5 was made public in September 2011 and holds 6.3 million quality controlled surface CO2 data points from the global oceans and coastal seas, spanning four decades (1968–2007). Three types of data products are available: individual cruise files, a merged complete data set and gridded products. With the rapid expansion of marine CO2 data collection and the importance of quantifying net global oceanic CO2 uptake and its changes, sustained data synthesis and data access are priorities

A Novel Approach for Shot Boundary Detection in Videos

This paper presents a novel approach for video shot boundary detection. The proposed approach is based on split and merge concept. A fisher linear discriminant criterion is used to guide the process of both splitting and merging. For the purpose of capturing the between class and within class scatter we employ 2D2 FLD method which works on texture feature of regions in each frame of a video. Further to reduce the complexity of the process we propose to employ spectral clustering to group related regions together to a single there by achieving reduction in dimension. The proposed method is experimentally also validated on a cricket video. It is revealed that shots obtained by the proposed approach are highly cohesive and loosely coupled

Search for High-energy Neutrinos from Binary Neutron Star Merger GW170817 with ANTARES, IceCube, and the Pierre Auger Observatory

The Advanced LIGO and Advanced Virgo observatories recently discovered gravitational waves from a binary neutron star inspiral. A short gamma-ray burst (GRB) that followed the merger of this binary was also recorded by the Fermi Gamma-ray Burst Monitor (Fermi-GBM), and the Anticoincidence Shield for the Spectrometer for the International Gamma-Ray Astrophysics Laboratory (INTEGRAL), indicating particle acceleration by the source. The precise location of the event was determined by optical detections of emission following the merger. We searched for high-energy neutrinos from the merger in the GeV--EeV energy range using the ANTARES, IceCube, and Pierre Auger Observatories. No neutrinos directionally coincident with the source were detected within $\pm500$ s around the merger time. Additionally, no MeV neutrino burst signal was detected coincident with the merger. We further carried out an extended search in the direction of the source for high-energy neutrinos within the 14-day period following the merger, but found no evidence of emission. We used these results to probe dissipation mechanisms in relativistic outflows driven by the binary neutron star merger. The non-detection is consistent with model predictions of short GRBs observed at a large off-axis angle.Comment: 22 pages, 2 figure