The Large Hadron Collider (LHC) at CERN facilitates collisions for four experimental stations, one of which is ALICE. ALICE is specifically dedicated to studying quark-gluon plasma (QGP) and involves researchers from 170 institutes across 40 countries. Recent findings indicate that the QGP behaves as the most perfect liquid ever observed in a laboratory setting. The data obtained from the LHC will significantly contribute to enhancing our understanding of the properties and evolution of the QGP. Within the ALICE experiment, the group is actively engaged in physics analysis, detector hardware, and GRID computing.
Overview
Core fields of research
Basic natural phenomena and mathematical thinking
Research areas
Particle physics
Faculty
Faculty of Mathematics and Science
Department
Department of Physics
Research group description
The Large Hadron Collider (LHC) at CERN is a facility that provides collisions of proton-proton, proton-lead, and lead-lead beams for four experimental stations: ALICE, ATLAS, CMS, and LHCb. Our focus is on the ALICE experiment, involving around 1800 researchers and engineers from 170 institutes in 40 countries. We have been members of ALICE since November 1997. ALICE activities in Jyväskylä are part of the Centre of Excellence (CoE) in Quark Matter at the Finnish Academy.
ALICE studies the properties of quark-gluon plasma (QGP), a state of matter where partons are no longer confined inside hadrons. Matter undergoes a deconfinement phase transition from hadronic matter to QGP at temperatures around 150 MeV. This transition happened in the early Universe a few microseconds after the Big Bang.
ALICE can track and identify particles with low transverse momenta, allowing detailed studies of the properties of the QGP. Current research focuses on investigating the detailed properties of hot and dense strongly interacting matter, including the fluidity of the matter measured by the shear viscosity to entropy ratio. Recent results show that the QGP is the most perfect liquid studied in the laboratory so far. The large statistics and precise data from the LHC will contribute to a better understanding of the properties and evolution of the QCD matter created in high-energy collisions.
In the ALICE experiment, our group has responsibilities in physics analysis, detector hardware, and GRID computing. Please find a more detailed description of our current research, personnel, and recent publications below.
Activities
We are happy to share that the ALICE Review Paper is now published in EPJC (10.08.2024):
The ALICE Review Paper covers key results from Runs 1 and 2, which have significantly impacted heavy-ion physics.
We thank the entire collaboration for their help. This work required contributions from ALICE at every level. We hope everyone is proud of the review and the hundreds of papers ALICE has produced. We look forward to ALICE in Run 3 and beyond as we continue exploring QCD.
Our third Bayesian analysis paper was submitted to a journal. Congratulations Maxim! arXiv:2411.01932
In the ALICE experiment, our group is responsible for physics analysis, detector hardware, and GRID computing. We work in close contact with the QCD theory group. To learn more about our recent research highlights, please refer to the JYFL Annual Report 2021 (p. 54), as well as the earlier 2000-2020 reports.
Physics analysis:A dense and hot droplet of strongly interacting matter is created in the ultra-relativistic collision between two heavy nuclei (URHIC). The droplet then expands and cools, and finally decouples to final state particles that are seen by the detector. Experimental data are then analyzed from many different points of view and our group is specialized in two directions: study collectivity through correlations of flow harmonics and correlations triggered by high momentum particles or jets.
Detector hardware: The ALICE detector underwent a major upgrade during the long shutdown 2 (LS2) period in the LHC from 2019-2020. Following the LS2, the LHC began operating at higher luminosity, and all detectors and electronics successfully met the new requirements. Our group was involved in two significant activities during LS2. We were involved in the Fast Interaction Trigger (FIT) (which was installed in 2022 during LS2) and the forward electromagnetic and hadronic calorimeter (FoCal) (which is planned to be installed during LS3 for data-taking in 2027–2029 at the LHC).
Grid computing: The ALICE experiment produces the order of 100 petabytes of data per year. All data and codes are in the secured storage and backup is guaranteed for all stages of data. Storing and backups are taken care of by the CERN IT experts. The Worldwide LHC Computing Grid (WLCG) provides the resources to store, distribute, and process the LHC data. WLCG combines the power of more than 170 collaborating centers in 36 countries around the world, which are linked to CERN. We are a part of WLCG through NDGF (Nordic Data Grid Facility) and maintain the Tier-1 site with the collaboration of Helsinki Institute of Physics and CSC (see us at ALICE Grid site map).
"Collective flow measurements from the large to small systems in LHC, Jyvaskyla activities", 11–16 Aug 2024, Flow Mini workshop in Femto and flow, https://indico.cern.ch/event/1372287/, Dong Jo Kim
"Flow in small and large systems", QCD Seminar, Jyvaskyla, March 22, 2024, Anna Onnerstad
"HEPScape in ALICE", CMS group, Helsinki, February 13, 2024, Anna Onnerstad
"The new ALICE Fast Interaction Trigger in LHC Run 3" Physics Days 2024 (Helsinki), Andreas Molander
Conferences, workshops, and schools in 2023
"HEPScape in ALICE", 26th International Particle Physics Outreach Group, 26 October 2022, Anna Onnerstad
"HEPScape in ALICE", ALICE week, CERN October, 2023, Anna Onnerstad
"Search for medium-induced jet quenching effects in high-multiplicity pp collisions with ALICE" Quark Matter 2023, 3–9 Sept 2023, Houston, Texas, USA, pdf, Dong Jo Kim
"Revisiting initial condition modeling with the Bayesian parameter estimation using the latest RHIC and LHC data"ALICE Physics Week 2023, 12–16 Jun 2023, Bucharest, Romania, pdf, Dong Jo Kim
"Revisiting Initial Condition Modeling of Heavy Ion Collisions with Bayesian Parameter Estimation"
[Heavy Ion Meeting, Yonsei University], South Korea, 26-27 May 2023, Dong Jo Kim
"Energy loss and transport from small to large systems"
[Seminar, Yonsei University], South Korea, 24-25 May 2023, Dong Jo Kim
"High-pt particle production, correlations, and observables sensitive to energy loss in small (and large) collision systems"
“Dijet invariant mass in pp and p–Pb collisions at √s_NN = 5.02 TeV with the ALICE detector at the LHC at CERN”, Talk at Tampere, 29.3.2023, Physics Days 2023. Laura Huhta.
“FOCAL Jet Studies”, Talk at ALICE Upgrade Week, 11.5.2023. Laura Huhta.
“Latest measurements of multiharmonic flow fluctuations in Pb–Pb collisions with ALICE”, Poster at Initial Stages 2023, Copenhagen, 19.06.2023. Cindy Mordasini.
“Constraining the medium properties with the anisotropic flow and its correlations in Pb–Pb collisions with ALICE”, Talk at Quark Matter 2023, Houston, 06.09.2023. Cindy Mordasini.
"Improving Bayesian parameter estimation with the latest RHIC and LHC data including a new initial conditions model" Spatind 2023(https://indico.cern.ch/event/1168768/), 3–8 Jan 2023, Maxim Virta
"Challenges of flow harmonic analysis in LHC collisions from large to small systems", Spatind 2023(https://indico.cern.ch/event/1168768/), 3–8 Jan 2023, Anna Onnerstad
Conferences, workshops, and schools in 2022
"Collective flow measurements from the large to small systems in LHC"
