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:
- CHERCHEURS NON-PERMANENTS / NON-PERMANENT RESEARCHERS:
Publications HAL


2022

Journal articles

Shreyasi Acharya, Dagmar Adamova, Alexander Adler, Jonatan Adolfsson, Gianluca Aglieri Rinella, et al.. Measurement of Prompt D^{0}, \Lambda_{c}^{+}, and \Sigma_{c}^{0,++}(2455) Production in Proton–Proton Collisions at \sqrt s = 13  TeV. Phys.Rev.Lett., 2022, 128 (1), pp.012001. ⟨10.1103/PhysRevLett.128.012001⟩. ⟨hal-03269684⟩ https://arxiv.org/pdf/2106.08278

Emilien Chapon, David d'Enterria, Bertrand Ducloue, Miguel G. Echevarria, Pol-Bernard Gossiaux, et al.. Prospects for quarkonium studies at the high-luminosity LHC. Prog.Part.Nucl.Phys., 2022, 122, pp.103906. ⟨10.1016/j.ppnp.2021.103906⟩. ⟨hal-03129560⟩ https://arxiv.org/pdf/2012.14161

Shreyasi Acharya, Dagmar Adamova, Alexander Adler, Jonatan Adolfsson, Gianluca Aglieri Rinella, et al.. Charm-quark fragmentation fractions and production cross section at midrapidity in pp collisions at the LHC. Phys.Rev.D, 2022, 105 (1), pp.L011103. ⟨10.1103/PhysRevD.105.L011103⟩. ⟨hal-03235647⟩ https://arxiv.org/pdf/2105.06335

2021

Journal articles

Shreyasi Acharya, Dagmar Adamova, Alexander Adler, Jonatan Adolfsson, Madan Mohan Aggarwal, et al.. Centrality dependence of J/\psi and \psi(2S) production and nuclear modification in p-Pb collisions at \sqrt{s_{\rm NN}} = 8.16 TeV. JHEP, 2021, 02, pp.002. ⟨10.1007/JHEP02(2021)002⟩. ⟨hal-02933928⟩

https://hal.archives-ouvertes.fr/hal-02933928/file/hal-02933928.pdf

U.A. Acharya, C. Aidala, Y. Akiba, M. Alfred, V. Andrieux, et al.. Probing Gluon Spin-Momentum Correlations in Transversely Polarized Protons through Midrapidity Isolated Direct Photons in p↑+p Collisions at s=200  GeV. Phys.Rev.Lett., 2021, 127 (16), pp.162001. ⟨10.1103/PhysRevLett.127.162001⟩. ⟨hal-03171397⟩ https://arxiv.org/pdf/2102.13585

Shreyasi Acharya, Dagmar Adamova, Alexander Adler, Jonatan Adolfsson, Madan Mohan Aggarwal, et al.. Pion-kaon femtoscopy and the lifetime of the hadronic phase in Pb-Pb collisions at \sqrt{s_{\rm{NN}}} = 2.76 TeV. Physics Letters B, Elsevier, 2021, 813, pp.136030. ⟨10.1016/j.physletb.2020.136030⟩. ⟨hal-02911938⟩

https://hal.archives-ouvertes.fr/hal-02911938/file/hal-02911938.pdf

Shreyasi Acharya, Dagmar Adamova, Alexander Adler, Jonatan Adolfsson, Gianluca Aglieri Rinella, et al.. Production of muons from heavy-flavour hadron decays at high transverse momentum in Pb–Pb collisions at sNN=5.02 and 2.76 TeV. Phys.Lett.B, 2021, 820, pp.136558. ⟨10.1016/j.physletb.2021.136558⟩. ⟨hal-03034788⟩ https://arxiv.org/pdf/2011.05718

Shreyasi Acharya, Dagmar Adamova, Alexander Adler, Jonatan Adolfsson, Gianluca Aglieri Rinella, et al.. Measurement of beauty and charm production in pp collisions at \sqrt{s} = 5.02 TeV via non-prompt and prompt D mesons. JHEP, 2021, 05, pp.220. ⟨10.1007/JHEP05(2021)220⟩. ⟨hal-03171339⟩ https://arxiv.org/pdf/2102.13601

Shreyasi Acharya, Dagmar Adamova, Alexander Adler, Jonatan Adolfsson, Madan Mohan Aggarwal, et al.. Elliptic Flow of Electrons from Beauty-Hadron Decays in Pb-Pb Collisions at \sqrt {s_{NN}} = 5.02 TeV. Physical Review Letters, American Physical Society, 2021, 126 (16), pp.162001. ⟨10.1103/PhysRevLett.126.162001⟩. ⟨hal-02863134⟩ https://arxiv.org/pdf/2005.11130

Shreyasi Acharya, Dagmar Adamova, Alexander Adler, Jonatan Adolfsson, Gianluca Aglieri Rinella, et al.. Production of pions, kaons, (anti-)protons and \phi mesons in Xe–Xe collisions at \sqrt{s_{\mathrm{NN}}} = 5.44 TeV. Eur.Phys.J.C, 2021, 81 (7), pp.584. ⟨10.1140/epjc/s10052-021-09304-4⟩. ⟨hal-03122301⟩ https://arxiv.org/pdf/2101.03100

Shreyasi Acharya, Dagmar Adamova, Alexander Adler, Jonatan Adolfsson, Gianluca Aglieri Rinella, et al.. Measurement of the production cross section of prompt {\Xi}_{\mathrm{c}}^0 baryons at midrapidity in pp collisions at \sqrt{s} = 5.02 TeV. JHEP, 2021, 10, pp.159. ⟨10.1007/JHEP10(2021)159⟩. ⟨hal-03235676⟩ https://arxiv.org/pdf/2105.05616

Shreyasi Acharya, Dagmar Adamova, Alexander Adler, Jonatan Adolfsson, Gianluca Aglieri Rinella, et al.. ϒ production and nuclear modification at forward rapidity in Pb–Pb collisions at sNN=5.02TeV. Phys.Lett.B, 2021, 822, pp.136579. ⟨10.1016/j.physletb.2021.136579⟩. ⟨hal-03034801⟩ https://arxiv.org/pdf/2011.05758

Shreyasi Acharya, Dagmar Adamova, Alexander Adler, Jonatan Adolfsson, Gianluca Aglieri Rinella, et al.. Experimental Evidence for an Attractive p-\phi Interaction. Phys.Rev.Lett., 2021, 127 (17), pp.172301. ⟨10.1103/PhysRevLett.127.172301⟩. ⟨hal-03235689⟩ https://arxiv.org/pdf/2105.05578

Shreyasi Acharya, Dagmar Adamova, Alexander Adler, Jonatan Adolfsson, Gianluca Aglieri Rinella, et al.. Coherent J/ \psi and \phi' photoproduction at midrapidity in ultra-peripheral Pb–Pb  collisions at \sqrt {s_{NN}} = 5.02 TeV. Eur.Phys.J.C, 2021, 81 (8), pp.712. ⟨10.1140/epjc/s10052-021-09437-6⟩. ⟨hal-03129415⟩ https://arxiv.org/pdf/2101.04577

Shreyasi Acharya, Dagmar Adamova, Alexander Adler, Jonatan Adolfsson, Gianluca Aglieri Rinella, et al.. Jet fragmentation transverse momentum distributions in pp and p-Pb collisions at \sqrt{s}, \sqrt{s_{\mathrm{NN}}} = 5.02 TeV. JHEP, 2021, 09, pp.211. ⟨10.1007/JHEP09(2021)211⟩. ⟨hal-03034786⟩ https://arxiv.org/pdf/2011.05904

U.A. Acharya, C. Aidala, Y. Akiba, M. Alfred, V. Andrieux, et al.. Transverse single-spin asymmetries of midrapidity \pi^0 and \eta mesons in polarized p+p collisions at \sqrt{s}=200 GeV. Physical Review D, American Physical Society, 2021, 103 (5), pp.052009. ⟨10.1103/PhysRevD.103.052009⟩. ⟨hal-03070632⟩

https://hal.archives-ouvertes.fr/hal-03070632/file/hal-03070632.pdf

U.A. Acharya, C. Aidala, Y. Akiba, M. Alfred, V. Andrieux, et al.. Transverse momentum dependent forward neutron single spin asymmetries in transversely polarized p+p collisions at \sqrt {s} = 200 GeV. Physical Review D, American Physical Society, 2021, 103 (3), pp.032007. ⟨10.1103/PhysRevD.103.032007⟩. ⟨hal-03070610⟩

https://hal.archives-ouvertes.fr/hal-03070610/file/hal-03070610.pdf

Shreyasi Acharya, Dagmar Adamova, Alexander Adler, Jonatan Adolfsson, Gianluca Aglieri Rinella, et al.. Measurements of mixed harmonic cumulants in Pb–Pb collisions at \sqrt {s_{NN}} = 5.02 TeV. Physics Letters B, Elsevier, 2021, 818, pp.136354. ⟨10.1016/j.physletb.2021.136354⟩. ⟨hal-03171343⟩ https://arxiv.org/pdf/2102.12180

Shreyasi Acharya, Dagmar Adamova, Alexander Adler, Jonatan Adolfsson, Gianluca Aglieri Rinella, et al.. Measurement of the Cross Sections of \Xi^0_{c} and \Xi^+_{c} Baryons and of the Branching-Fraction Ratio BR(\Xi^0_{c} \rightarrow \Xi^-{e}^+\nu_{ e})/BR(\Xi^0_{c} \rightarrow \Xi^-\pi^+) in pp collisions at 13 TeV. Phys.Rev.Lett., 2021, 127 (27), pp.272001. ⟨10.1103/PhysRevLett.127.272001⟩. ⟨hal-03235693⟩ https://arxiv.org/pdf/2105.05187

Shreyasi Acharya, Dagmar Adamova, Alexander Adler, Jonatan Adolfsson, Madan Mohan Aggarwal, et al.. Soft-Dielectron Excess in Proton-Proton Collisions at \sqrt{s} = 13 TeV. Physical Review Letters, American Physical Society, 2021, 127 (4), pp.042302. ⟨10.1103/PhysRevLett.127.042302⟩. ⟨hal-02870821⟩ https://arxiv.org/pdf/2005.14522