Inspire
Location
Orsay, Essonne | France
Job description
Job description:
POSTDOCTORAL POSITION – ANR – YEAR 2024-2026
ALICE group IJCLab Orsay (CNRS/IN2P3)
DEADLINE for application: review of applications will begin immediately and a first
deadline is set to the 21st March 2024 (application will be accepted until the position
is filled)
PROJECT TITLE
Data analysis of quarkonium photoproduction from peripheral to central Pb-Pb collisions in ALICE, and associated phenomenological studies for fixed-target collisions at LHC
JOB DESCRIPTION
We invite applications for a highly motivated post-doctoral researcher for a 2-year duration to work on the study of quarkonium photoproduction from peripheral to central Pb-Pb collisions with Run3 data in ALICE. The candidate will work on the analysis code development in the O2 framework to perform the measurement of the photoproduced J/psi cross section, in the dimuon decay channel, with the ALICE forward muon spectrometer. Benefiting from the high statistics of Pb-Pb data collected in 2023, the candidate will perform multi-differential measurements in centrality/rapidity of the J/psi photoproduction cross section and will extend the work to other quarkonia (Psi(2S)) if feasible. The candidate will also conduct phenomenological studies using the STARLIGHT MC generator for quarkonium photoproduction measurements in fixed target mode at the LHC. The researcher will be based at IJCLab (CNRS/IN2P3), Orsay, France in the ALICE group with frequent travels to CERN. The candidate is expected to take shifts during the data taking and ensure a service work task in the Dilepton and Quarkonia working group of ALICE. The position is funded for two years and can be filled as soon as 1st. June 2024.
DESCRIPTION OF THE PROJECT
The project concerns the analysis of ALICE Run3 data. ALICE offers unique capabilities to study quarkonium production at low transverse momentum over a wide rapidity range. In ultra-peripheral collisions (UPC), nuclei are separated by impact parameters larger than the sum of their radii and therefore hadronic interactions are strongly suppressed. Photoproduction of vector mesons, in such collisions, gives insight into the gluon distribution of the incoming Pb nuclei over a broad range of Bjorken-x values. The first indication of J/psi coherent photoproduction measured by ALICE [1] at forward rapidity in Peripheral Collisions (PC) with nuclear overlap brings yet another handle to this kind of measurements. The experimental and theoretical challenges of quarkonium photoproduction measurements in AA collisions with nuclear overlap, are still manyfold. Indeed, the observed J/psi excess at low transverse momentum (pT), interpreted as originating from coherent photoproduction, imposes great challenges for the existing coherent photoproduction models, especially in explaining how the broken nuclei satisfy the requirement of coherence. The high statistics Pb-Pb data collected in 2023 will permit extending Run 2 measurements [2] to more central collisions allowing one to investigate the role of spectator nucleons on the coherence condition, and potential interactions of the photoproduced vector meson with the Quark Gluon Plasma. In addition, multi-differential measurements as a function of centrality and rapidity will permit further constraining theoretical models recently developed to describe quarkonium photoproduction in AA collisions with nuclear overlap. If statistics allow, the previous studies will be extended to other quarkonia for the first time. The project also foresees phenomenological studies with the STARLIGHT MC generator [3] to explore quarkonium photoproduction opportunities at lower center-of-mass energies, in fixed target mode at the LHC. This work can benefit from the longstanding collaboration between the ALICE team and the theory pole of IJCLab (see earlier work in [4]). The ALICE IJCLab group is composed of 5 permanent researchers, 2 PhD students, and 1 postdoc. We are deeply involved in quarkonium analyses at forward rapidity in all colliding systems, as well as in heavy flavor production and Z boson production. The group is responsible for and built the first tracking station of the muon spectrometer. During LS2, the group was strongly involved in the upgrade of the muon tracking chamber readout electronics.
EXPECTED PROFILE
Applicants are expected to hold a PhD degree in subatomic physics or in a related field.
Good programming and computational skills are required. In particular, experience in simulations and data analysis, in a large experimental collaboration, will be considered a
plus. The eligible candidate should be able to communicate at a scientific level in English. Knowledge of French, although not essential, would be useful. The University of
Paris-Saclay is an equal opportunity/affirmative action employer. The appointment is for two years (ANR funding). To be eligible, applicants must have obtained their PhD degree by the date of appointment and preferentially no more than 7 years ago, at the start of the contract. Monthly gross salary will be between €2992 and €3431 (for a candidate with 0 to 2 years of experience after PhD) or €4204 (for a candidate with more than 2 years of experience after PhD). It corresponds to a net salary before income tax ranging from about €2500 to €2900 (0 to 2 years of experience) or €3570 (more than 2 years of experience). Review of applications will begin immediately and will continue until the position is filled.
APPLICATION:
The applications (including a CV, a statement of research, a cover letter) are to be sent to: Laure Massacrier - [email protected]
The applicants should arrange 3 letters of recommendation to be sent separately at the
same address.
In addition, an online application needs to be filled at the following link (mandatory):
https://emploi.cnrs.fr/Offres/CDD/UMR9012-MARLOU-042/Default.aspx?lang=EN
For further information please contact Laure Massacrier ([email protected])
LABORATORIES INVOLVED
Laboratoire de Physique des 2 infinis Irène Joliot-Curie (IJCLab) CNRS/IN2P3
15, Rue G. Clemenceau
91405 ORSAY cedex (FRANCE)
REFERENCES
[1] Measurement of an excess in the yield of J/ψ at very low pT in Pb-Pb collisions at
√sNN = 2.76 TeV
By J. Adam et al., Phys. Rev. Lett., 116 (2016) 222301
[2] Photoproduction of low pT J/ψ from peripheral to central Pb-Pb collisions at √sNN =
5.02 TeV
by S. Acharya et al., Phys. Lett. B 846 (2023) 137467
[3] STARlight: A Monte Carlo simulation program for ultra-peripheral collisions of
relativistic ions
by S. Klein et al., Comput.Phys.Commun. 212 (2017) 258-268
[4] Single-Transverse-Spin asymmetries in exclusive photoproduction of J/psi in UPC in
the fixed target mode at the LHC and in collider mode at RHIC
by J.P. Lansberg et al., Phys. Lett. B 793 (2019) 33-40
Job tags
Salary
2 992 € a 3 431 €
