The international collaboration ALICE (“A Large Ion Collider Experiment”), of which the eponymous research group of the IP2I in Lyon is a member, aims to study nuclear matter in a state of extremely high temperature, where the deconfinement of hadrons (including protons and neutrons) into plasma of quarks and gluons takes place.
Matter is made up of atoms, themselves made up of electrons surrounding a nucleus of protons and neutrons, the latter being formed of quarks, linked by gluons. No quark or gluon has ever been observed in isolation: they appear to be permanently bonded together and confined in composite particles. At temperatures 100,000 times higher than those at the centre of the Sun, they deconform to form a plasma, which would have existed a few microseconds after the Big Bang. This plasma is predicted by the fundamental theory of strong interaction, Quantum Chromodynamics (QCD), and its study allows us to understand the ultimate organization of matter subject to strong interaction and the very first moments of the universe.
The LHC collides lead ions to recreate conditions similar to those immediately after the Big Bang and form this quark and gluon plasma. For this infinitely small study, a huge detector has been built at the LHC. It is capable of measuring the particles emitted by the plasma as it expands and cools.
Our group has been involved in this construction and in obtaining major results in this field of physics.
The activities of the ALICE group of the IP2I of Lyon are twofold:
- the analysis of data collected in proton-proton, proton-nucleus and nucleus-nucleus collisions at the CERN LHC
- participation in the construction and operation of the forward vertex trajectograph, the Muon Forward Tracker
Analysis of data collected in proton-proton, proton-nucleus and nucleus-nucleus collisions at the CERN LHC
The physics analyses of the ALICE experiment carried out in the Lyon groups cover a wide range of subjects, from the light quark sector u, d, s with the study of the forward production of low mass vector mesons 
and 
in the dimuonic decay channel, to the heavy quarks sector c and b, with the study of the production of the quarkonium states of the 
and 
families. This analytical work has already led to a number of remarkable results, notably through the study of collective phenomena characterizing the evolution of the and mesons, namely the appearance of kinematic correlations between the meson and light hadrons in high multiplicity proton-Pb collisions, and the observation of elliptical flow of the 
meson compatible with zero in Pb-Pb collisions (behavior different from all the other particles studied).
Participation in the construction and operation of the forward vertex trajectograph, the Muon Forward Tracker
The group is also responsible for the construction and operation of the vertex forward trajectograph, the Muon Forward Tracker (MFT), one of the first applications in high energy physics of CMOS silicon pixel sensor technology. The MFT, which will be integrated into the ALICE detector starting with Run3 of the LHC (2021), is designed to enable precise measurement of the details of the vertex region for forward-produced particles, especially muons, whose different topologies and production processes can be studied.
NON-PERMANENTS:
- DOCTORANTS / DOCTORAL STUDENTS:
- D. Sillou, M. Besancon, M. Dejardin, D. Denegri, B. Fabbro, et al.. Search for Dijet Resonances in 7 TeV pp Collisions at CMS. Physical Review Letters, 2010, 105, pp.211801. ⟨10.1103/PhysRevLett.105.211801⟩. ⟨in2p3-00525737⟩
- C.E Vaudey, N. Toulhoat, N. Moncoffre, N. BĂ©rerd. Effets de la tempĂ©rature et de la radiolyse sur la distribution et la spĂ©ciation du chlore dans le graphite nuclĂ©aire. JournĂ©es annuelles du GNR PARIS, 2010, Avignon, France. ⟨in2p3-01018520⟩
- O. StĂ©zowski. Informatique, simulation et analyse. Ecole IN2P3 d'instrumentation "de la physique au dĂ©tecteur", 2010, FrĂ©jus, France. ⟨in2p3-00765343⟩
- J. Dupuis, E. Fourmond, D. Ballutaud, N. Bererd, M. Lemiti. Optical and structural properties of silicon oxynitride deposited by plasma enhanced chemical vapor deposition. Thin Solid Films, 2010, 519, pp.1325-1333. ⟨10.1016/j.tsf.2010.09.036⟩. ⟨in2p3-00734027⟩
- Ngoc-Long Do, N. BĂ©rerd, N. Moncoffre, D. Gorse-Pomonti. Damage generated by MeV-ion beams on titanium surface in oxidizing environment. 2010 MRS Fall Meeting - Symposium Q/R/T - Advanced Materials for Applications in Extreme Environments, 2010, Boston, United States. ⟨10.1557/opl.2011.372⟩. ⟨in2p3-00734357⟩
- C.-E. Vaudey, N. Toulhoat, N. Moncoffre, N. BĂ©rerd, C. Peaucelle. Use of a gas irradiation cell to study the effects of nuclear graphite radiolytic corrosion on the behaviour of chlorine. E-MRS 2010, 2010, Strasbourg, France. ⟨in2p3-01018341⟩
- D. Sillou, M. Besancon, M. Dejardin, D. Denegri, J. Descamps, et al.. CMS Tracking Performance Results from early LHC Operation. European Physical Journal C: Particles and Fields, 2010, 70, pp.1165-1192. ⟨10.1140/epjc/s10052-010-1491-3⟩. ⟨in2p3-00508542⟩
- S. Chatrchyan, P. Nedelec, D. Sillou, M. Besancon, R. Chipaux, et al.. Alignment of the CMS Silicon Tracker during Commissioning with Cosmic Rays. Journal of Instrumentation, 2010, 5(03), pp.T03009. ⟨10.1088/1748-0221/5/03/T03009⟩. ⟨in2p3-00664774⟩
- K. Aamodt, N. Abel, U. Abeysekara, A. Abrahantes Quintana, A. Acero, et al.. First proton--proton collisions at the LHC as observed with the ALICE detector: measurement of the charged particle pseudorapidity density at
= 900 GeV. European Physical Journal C: Particles and Fields, 2010, 65, pp.111-125. ⟨10.1140/epjc/s10052-009-1227-4⟩. ⟨in2p3-00437986⟩ - K. Aamodt, N. Abel, U. Abeysekara, A. Abrahantes Quintana, A. Abramyan, et al.. Two-pion Bose-Einstein correlations in pp collisions at sqrt(s)=900 GeV. Physical Review D, 2010, 82, pp.052001. ⟨10.1103/PhysRevD.82.052001⟩. ⟨in2p3-00498218⟩
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