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:

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 \rho, \omega and \phi 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 J/\psi and \Lambda 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 J/\psi and \Lambda mesons, namely the appearance of kinematic correlations between the J/\psi meson and light hadrons in high multiplicity proton-Pb collisions, and the observation of elliptical flow of the \Upsilon(1S) 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.

PERMANENTS:
NON-PERMANENTS:

- DOCTORANTS / DOCTORAL STUDENTS:
    1804 documents

    • A. S. Cornell, A. Deandrea, Lu-Xin Liu, A. Tarhini. Renormalisation running of masses and mixings in UED models. Modern Physics Letters A, 2013, 28, pp.1330007. ⟨10.1142/S0217732313300073⟩. ⟨in2p3-00747518⟩
    • J. Sorce, H.M. Courtois, K. Sheth, R. Brent Tully. Bimodality of Galaxy Disk Central Surface Brightness Distribution in the Spitzer 3.6 micron band. Monthly Notices of the Royal Astronomical Society, 2013, 433, pp.751-758. ⟨10.1093/mnras/stt768⟩. ⟨in2p3-00826379⟩
    • Y. Uesugi, T. Akagi, R. Chehab, O. Dadoun, K. Furukawa, et al.. Development of an intense positron source using a crystal--amorphous hybrid target for linear colliders. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2013, 319, pp.17-23. ⟨10.1016/j.nimb.2013.10.025⟩. ⟨in2p3-00914266⟩
    • M. J. Childress, G. Aldering, P. Antilogus, C. Aragon, S. Bailey, et al.. Host Galaxy Properties and Hubble Residuals of Type Ia Supernovae from the Nearby Supernova Factory. The Astrophysical Journal, 2013, 770, pp.108. ⟨10.1088/0004-637X/770/2/108⟩. ⟨in2p3-00826354⟩
    • G. Cacciapaglia. Presentation at Workshop Origin of the Mass 2013. Workshop Origin of the Mass 2013, 2013, Odense, Denmark. ⟨in2p3-01025125⟩
    • A. Abdalgabar, As. Cornell, A. Deandrea, A. Tarhini. Higgs quartic coupling and neutrino sector evolution in 2UED models. European Physical Journal C: Particles and Fields, 2013, 74, pp.2893. ⟨10.1140/epjc/s10052-014-2893-4⟩. ⟨in2p3-00848087⟩
    • A. S. Cornell, A. Deandrea, Lu-Xin Liu, A. Tarhini. The evolution of neutrino masses and mixings in the 5D MSSM. The European Physical Journal Plus, 2013, 128, pp.6. ⟨10.1140/epjp/i2013-13006-4⟩. ⟨in2p3-00722268⟩
    • S. Chatrchyan, M. Besancon, S. Choudhury, M. Dejardin, D. Denegri, et al.. Search for new physics in events with opposite-sign leptons, jets, and missing transverse energy in pp collisions at sqrt(s) = 7 TeV. Physics Letters B, 2013, 718, pp.815-840. ⟨10.1016/j.physletb.2012.11.036⟩. ⟨in2p3-00709565⟩
    • A. Vancraeyenest, C. Petrache, D. Guinet, P. T. Greenlees, U. Jakobsson, et al.. Identification of new transitions feeding the high-spin isomers in ^{139}Nd and ^{140}Nd nuclei. Physical Review C, 2013, 87, pp.064303. ⟨10.1103/PhysRevC.87.064303⟩. ⟨in2p3-00832587⟩
    • A. Pastore, J. Margueron, P. Schuck, X. Viñas. Pairing in exotic neutron rich nuclei around the drip line and in the crust of neutron stars. Physical Review C, 2013, 88, pp.034314. ⟨10.1103/PhysRevC.88.034314⟩. ⟨in2p3-00804120⟩