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:
- Nicolas Arnaud, Caroline Andreazza, Marie Lauvergeon-Gourdon, Sophie Rémy, Fabrice Thalmann, et al.. La Nuit des ondes gravitationnelles : a multi-site outreach event about gravitational waves. The European Physical Society Conference on High Energy Physics (EPS-HEP) 2017, Jul 2017, Venise, Italy. ⟨in2p3-03960089⟩
- Sijing Zhang. Searches for additional Higgs bosons at CMS. 20th International Conference in Quantum Chromodynamics (QCD 17), 3-7 Jul 2017, Montpellier (France), Jul 2017, Montpellier, France. ⟨hal-02071350⟩
- Nicolas Chanon. Production associée de quarks Top et du boson de Higgs. Congrès de la Société Française de Physique (SFP) 2017, Jul 2017, Orsay, France. ⟨hal-02052695⟩
- Mattia Fontana, Jean-Luc Ley, Etienne Testa, Jean Michel Létang, Voichita Maxim, et al.. Versatile Compton camera for high energy gamma rays: Monte Carlo comparison with Anger camera for medical imaging. 2nd Jagiellonan Symposium on Fundamental and Applied Subatomic Physics, Jun 2017, Krakow, Poland. pp.1639-1645, ⟨10.5506/APhysPolB.48.1639⟩. ⟨hal-01609541⟩
- Emeline Queguiner. Low-Mass WIMP Search with the EDELWEISS experiment: Latest Results and Developments. 29th Rencontres de Blois, May 2017, Blois, France. ⟨hal-02060159⟩
- Hugues Lattaud. Gamma + jet, residual jet energy correction. Helsinki JetMet workshop physics at 100fb-1, May 2017, Helsinki, Finland. ⟨hal-02023481⟩
- Nils Krah, Mauro Testa, Simon Rit, Ilaria Rinaldi. How much can range accuracy in proton therapy be improved through patient specific optimization of the HU-RSP conversion curve?. 56th annual conférence of the Particle Therapy Co-operative Group - PTCOG 56, May 2017, Pacifico Yokohama, Yokohama, Japan. ⟨10.14338/IJPT.17-PTCOG-1.1⟩. ⟨hal-01714201⟩
- S. Beauceron. search for VLQ in single production. TOP LHC France, May 2017, Marseille, France. ⟨hal-02063429⟩
- E. Armengaud, Q. Arnaud, C. Augier, A. Benoît, L. Bergé, et al.. Measurement of the cosmogenic activation of germanium detectors in EDELWEISS-III. Astroparticle Physics, 2017, 91, pp.51-64. ⟨10.1016/j.astropartphys.2017.03.006⟩. ⟨in2p3-01345962⟩
- Anne-Sophie Wozny, Alexandra Lauret, Priscillia Battiston-Montagne, Jean-Baptiste Guy, Michael Beuve, et al.. Differential pattern of HIF-1α expression in HNSCC cancer stem cells after carbon ion or photon irradiation: one molecular explanation of the oxygen effect. British Journal of Cancer, 2017, 116 (10), pp.1340 - 1349. ⟨10.1038/bjc.2017.100⟩. ⟨cea-01938093⟩
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