Hadron physics

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 $\rho, \omega$ 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:

- CHERCHEURS NON-PERMANENTS / NON-PERMANENT RESEARCHERS:

BAILUNG Yoshini

1820 documents

Shreyasi Acharya, Dagmar Adamova, Gianluca Aglieri Rinella, Michelangelo Agnello, Neelima Agrawal, et al.. Multiplicity-dependent production of $\Sigma(1385)^{\pm}$ and $\Xi(1530)^{0}$ in pp collisions at $\sqrt{s}=13$ TeV. JHEP, 2024, 05, pp.317. ⟨10.1007/JHEP05(2024)317⟩. ⟨hal-04199223⟩
Shreyasi Acharya, Dagmar Adamova, Gianluca Aglieri Rinella, Michelangelo Agnello, Neelima Agrawal, et al.. Skewness and kurtosis of mean transverse momentum fluctuations at the LHC energies. Phys.Lett.B, 2024, 850, pp.138541. ⟨10.1016/j.physletb.2024.138541⟩. ⟨hal-04199220⟩
Shreyasi Acharya, Dagmar Adamova, Apar Agarwal, Gianluca Aglieri Rinella, Luca Aglietta, et al.. Measurement of beauty production via non-prompt charm hadrons in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}} = 5.02$ TeV. JHEP, 2024, 11, pp.148. ⟨10.1007/JHEP11(2024)148⟩. ⟨hal-04660005⟩
Shreyasi Acharya, Dagmar Adamova, Gianluca Aglieri Rinella, Michelangelo Agnello, Neelima Agrawal, et al.. Measurements of chemical potentials in Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV. Phys.Rev.Lett., 2024, 133 (9), pp.092301. ⟨10.1103/PhysRevLett.133.092301⟩. ⟨hal-04323142⟩
Shreyasi Acharya, Dagmar Adamova, Gianluca Aglieri Rinella, Michelangelo Agnello, Neelima Agrawal, et al.. Measurements of long-range two-particle correlation over a wide pseudorapidity range in p $-$ Pb collisions at $\sqrt{s_{\rm NN}}=5.0$ TeV. JHEP, 2024, 01, pp.199. ⟨10.1007/JHEP01(2024)199⟩. ⟨hal-04210137⟩
Shreyasi Acharya, Dagmar Adamova, Gianluca Aglieri Rinella, Michelangelo Agnello, Neelima Agrawal, et al.. Multiplicity dependence of charged-particle intra-jet properties in pp collisions at $\sqrt{s}$ = 13 TeV. Eur.Phys.J.C, 2024, 84 (10), pp.1079. ⟨10.1140/epjc/s10052-024-13228-0⟩. ⟨hal-04323096⟩
Shreyasi Acharya, Dagmar Adamova, Gianluca Aglieri Rinella, Michelangelo Agnello, Neelima Agrawal, et al.. Measurements of jet quenching using semi-inclusive hadron+jet distributions in pp and central Pb $-$ Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV. Phys.Rev.C, 2024, 110 (1), pp.014906. ⟨10.1103/PhysRevC.110.014906⟩. ⟨hal-04210138⟩
Shreyasi Acharya, Dagmar Adamova, Apar Agarwal, Gianluca Aglieri Rinella, Luca Aglietta, et al.. Measurement of beauty-quark production in pp collisions at $\sqrt{s}=13$ TeV via non-prompt D mesons. JHEP, 2024, 2024, pp.110. ⟨10.1007/JHEP10(2024)110⟩. ⟨hal-04482538⟩
Shreyasi Acharya, Dagmar Adamova, Alexander Adler, Gianluca Aglieri Rinella, Michelangelo Agnello, et al.. Measurement of the low-energy antitriton inelastic cross section. Phys.Lett.B, 2024, 848, pp.138337. ⟨10.1016/j.physletb.2023.138337⟩. ⟨hal-04158575⟩
Shreyasi Acharya, Dagmar Adamova, Gianluca Aglieri Rinella, Michelangelo Agnello, Neelima Agrawal, et al.. Observation of medium-induced yield enhancement and acoplanarity broadening of low- $p_\mathrm{T}$ jets from measurements in pp and central Pb $-$ Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV. Phys.Rev.Lett., 2024, 133 (2), pp.022301. ⟨10.1103/PhysRevLett.133.022301⟩. ⟨hal-04199251⟩