The Accelerators, Cryogeny and Magnetism Division

Depuis l'annonce spectaculaire de juillet 2012, les physiciens ont analysé deux fois et demie plus de données que ce qui était alors disponible. Leurs derniers résultats ont été présentés jeudi 7 mars à La Thuile, dans les Alpes italiennes, lors des "Rencontres de Moriond", la première conférence de physique majeure de l'année. 

The scientific community had to wait 18 months for the data collected by Planck, the European Space Agency satellite. Now, the first scientific results are in. The first edition of the compact sources catalog (ERCSC, Early Release Compact Sources Catalogue), with several thousand sources detected by Planck, has been published and presented in the context of an international colloquium, held from 11th to 14th January 2011 at the Cité des Sciences et de l'Industrie in La Villette (Paris).

Read the joint press release from CNES, CNRS, CEA, and ESA

Also refer to the program of the colloquium

The Sloan Digital Sky Survey III, a collaboration with contributions from researchers at the CNRS and CEA, has just released the widest sky survey ever carried out to the international scientific community at the annual meeting of the American Astronomy Society held in Seattle between January 10 and 13, 2011. This survey provides an image and a catalog of sources covering almost all of the sky in five colors and with a quality never before achieved in terms of the sky coverage and the accuracy of the luminosity measurements. The catalog, containing around 470 million objects (galaxies, stars, quasars, etc.), will be published in the Astrophysical Journal Supplements.

Thierry LASSERRE

Christian VEYSSIERE 

In August 2010 at CERN in Geneva, a team of physicists from SEDI and SPP working in collaboration with a group from ETH-Zurich obtained the first successful results from a MicroMegas detector operating in a time projection chamber filled with pure cryogenic argon at a temperature of 87.2 kelvin. 

 The Planck satellite has just discovered a supercluster of galaxies thanks to its imprint on fossil radiation—witness to the first moments in the life of the Universe. This is a first for the satellite, which also revealed new clusters of galaxies with great precision. 

These objects, which contain hundreds or thousands of galaxies, are the largest known structures in the Universe. Thanks to these data, scientists hope to gain a better understanding of how dark matter and visible matter come together in the form of these structures.

Physicist working on the CDF and D0 experiments using Fermilab's Tevatron accelerator in Chicago, including scientists from IN2P3/CNRS and IRFU/CEA, announced their latest results on 26 July at the International Conference on High-Energy Physics (ICHEP 2010) in Paris. Their measurement further constrain the Higgs boson mass domain still open within the standard model of particle physics. This means that CDF and D0 have ruled out a Higgs Boson with a mass between 158 and 175 GeV/c².

An increasing amount of experimental results points to a low mass for this famous boson; will a solution to this puzzle be found sometime in the next two years strong?

The 35^th International Conference on High-Energy Physics was held at the Palais des Congrès in Paris from 22 to 28 July—an opportunity for the LHC teams to present their first results. IRFU is involved in three of the four major collaborative projects that have set up their detectors at the collision points in the ring: Alice, Atlas, and CMS. Our teams have contributed in particular to some fundamental analyses for the control of the detectors, whose performance has exceeded expectations.

The D0 experiment at the Tevatron accelerator at Fermilab (Chicago), in which physicists from CEA/IRFU and CNRS/IN2P3 are involved, has measured a significant matter-antimatter _asymmetry_ in the behaviour of particles containing b quarks, known as B mesons (or beauty mesons) beyond the predictions of the standard model (the current theory of particle physics). This result has been submitted for publication in the Journal Physical Review D.

On April 14, Thierry Lasserre received the CNRS bronze medal from the new director of the In2p3, Jacques Martino. Since 1954, CNRS has awarded three medals each year to renowned researchers or promising young scientists. This Bronze Medal rewards a researcher's first work, which marks that person as a promising specialist in his or her field. The work of Thierry Lasserre concerned the most abundant massive particle in the universe: the neutrino.

The LHC is about to start up for an initial two-year period of data acquisition which will produce a flow rate and volume of data among the largest that the man has ever needed to process. During recent tests under real conditions, the Paris region research grid (GRIF) was able to provide the required performance, allowing physicists to access reconstructed data only four hours after it had been recorded at CERN. In 2010, the volume of data to process will be 100 times larger. The teams from IRFU have shown, by this first success, that they will be ready to meet this challenge.

The Phenix and Star collaborations, which include physicists from CEA-IRFU and CNRS-IN2P3, have announced major discoveries on the nature of the quark-gluon plasma. These conclusive results, which advance our understanding of nuclear material subjected to extreme conditions, shed new light on the birth of the universe. They have been published in the journal Physical Review Letters.

A company from the Vosges Department in France, NEOTEC, received the 2009 "Outstanding Implementations" award, at the International MIDEST Exhibition attended by the Industry Minister, Christian Estrosi, for their production of very special chambers. This equipment forms part of an important component of the Double-Chooz experiment which, before the end of the year, will measure neutrinos emitted by the reactor at the Chooz nuclear power station in the Ardennes.

Since the restart of the LHC on 20 November, CMS has taken advantage of the excellent operating performance of the collider to record a large amount of useful data. This is now being used to check its correct operation and calibration. During this period, CMS has demonstrated the stability of the detectors' working conditions as well as the efficiency of the data analysis system, which sends data from the detector to analysis teams around the world, and this in spite of very rapidly changing beam conditions.

The Baryon Oscillation Spectroscopic Survey - known as Boss - delivered its first data during the night of 14-15 September. This experiment, devoted to the search for baryon oscillations, heralds the start of a new era of research into dark energy and the evolution of the Universe. Several teams are involved in BOSS, in particular from IN2P3⁽¹⁾/CNRS, INSU⁽²⁾/CNRS and CEA.

On November 14, 2008, the Compact Muon Solenoid (CMS) successfully generated a nominal magnetic field of 4 tesla. This success rewards IRFU efforts for the design and construction of what constitutes the largest superconducting solenoid magnet in the world. Over a period of approximately one month, CMS teams conducted a continuous data acquisition campaign with the detector operating under nominal conditions. Approximately 300 million cosmic events were recorded. This also provided an excellent opportunity to showcase the specific expertise of IRFU teams, particularly in areas such as detection systems, electronics, trace data reconstruction techniques and laser control systems.

Shortly after the LHC started up on the 10^th September 2008 at 9:30 am, the detectors recorded the first events resulting from proton collisions in the beam detectors. The data processing scheme that had been planned for such a long time immediately came into action with the distribution of data to the Tier0 data centre, then the eleven Tier1 data centres, and finally the Tier2 data centres.

The last two lines of the ANTARES detector were connected and powered at a depth of 2500 m on the Mediterranean seabed during the night of May 30, 2008. This brings the number of lines to twelve and completes the construction phase of the largest underwater neutrino telescope ever built.
The lines were immersed a few weeks earlier, close to the other lines that have been tracking cosmic neutrinos since 2006. These particles may be able to tell us more about the most violent phenomena in the Universe.
The event rewards the efforts of the European ANTARES collaboration1 and, more especially, of CEA-IRFU, which has been a major contributor to the project.