Light ion collisions at the LHC - 2025

1 Dec 2025, 09:00 → 3 Dec 2025, 18:00 Europe/Zurich

6/2-024 - BE Auditorium Meyrin (CERN)

Aleksas Mazeliauskas (Heidelberg University (DE)), Georgios Krintiras (The University of Kansas (US)), Giuliano Giacalone, Wilke Van Der Schee (CERN)

We are pleased to announce the 2025 edition of the Light Ion Collisions at the LHC workshop.

The workshop aims to bring the community together for celebrating and assessing the scientific reach of experimental results on light-ion collisions collected at the LHC in July 2025.

The goal is to clarify what we have learned from existing measurements and to define the most pressing open questions going forward. We will also hold a community discussion on the scientific potential of future light-ion runs in 2026 and beyond.

Workshop topics include:

• Experimental overviews of collectivity and energy loss
• Hydrodynamics and non-equilibrium dynamics
• Jet quenching in small systems
• nPDFs of light ions
• Synergies with nuclear structure physics and other areas
• Accelerator and experiments perspectives for future light-ion runs

Anyone interested in the workshop is invited to register.

The organizers,

• Reyes Alemany Fernandez (CERN)
• Giuliano Giacalone (CERN)
• Qipeng Hu (USTC Hefei)
• Gian Michele Innocenti (MIT)
• Georgios Krintiras (University of Kansas)
• Saverio Mariani (CERN)
• Aleksas Mazeliauskas (ITP Heidelberg)
• Dennis Perepelitsa (CU Boulder)
• Anthony Timmins (University of Houston)
• Wilke van der Schee (CERN)
• Urs Wiedemann (CERN)
• You Zhou (NBI Copenhagen) 

 

 

LIC_2025_poster.pdf

Monday 1 December

09:00 → 09:10 Welcome

09:10 → 10:40 Machine and experimental soft-probes reports

Convener: You Zhou (Niels Bohr Institute (DK))

09:10 Overview of performance of the 2025 oxygen and neon run

Speaker: Theodoros Argyropoulos (CERN)

OxygenNeonPerformance2025_TA.pdf

OxygenNeonPerformance2025_TA.pptx

09:25 ALICE overview soft

Speaker: Emil Gorm Nielsen (University of Copenhagen (DK))

lightion_lhc_2025_egnielsen.key

lightion_lhc_2025_egnielsen.pdf

09:40 ATLAS overview soft

Speaker: Blair Daniel Seidlitz (Columbia University (US))

BSeidlitz_COLLECTIVITY_ATLAS_softPhys.pdf

09:55 CMS overview soft

Speaker: Aryaa Dattamunsi (Indian Institute of Technology Madras (IN))

10:10 LHCb overview soft

Speaker: Zhengchen Lian (Tsinghua University (CN))

10:25 STAR overview soft

Speaker: Prof. Chunjian Zhang (Fudan University (CN))

10:40 → 11:00 Coffee break

11:00 → 12:15 Soft Physics in Light-Ion Collisions

11:00 Predictions for light-ions

Speaker: Wenbin Zhao (Peking University)

11:15 Predictions for light-ions

Speaker: Dr Wilke Van Der Schee (CERN)

11:30 Longitudinal structure of light-ion collisions

Speaker: Andreas Kirchner

11:45 Light-ions with McDipper initial conditions

Speaker: Oscar Garcia-Montero (Universität Bielefeld)

12:00 Flow in light ion collisions from kinetic theory and inferences on hydrodynamisation

Speaker: Clemens Werthmann (Ghent University)

Werthmann_light_ion_collisions_2025.pdf

12:15 → 14:00 Lunch break

14:00 → 15:30 Soft Physics in Light-Ion Collisions

14:00 Collective Dynamics and Opacity Estimation in OO Collision Systems via CoMBolt-ITA

Speaker: Seyed Farid Taghavi (Technische Universitaet Muenchen (DE))

14:15 Causality Constraints to Multi-Particle Cumulants: Testing Different System Sizes at the LHC

Speaker: Isabella Danhoni

14:30 Collective flow in transport models

Speaker: Lucas Constantin

CERN_presentation.pdf

14:45 Discussion: Do we understand collectivity in small systems?

Speakers: Oscar Garcia-Montero (Universität Bielefeld), Raimond Snellings (Nikhef National institute for subatomic physics (NL)), Sunil Jaiswal

15:30 → 16:00 Coffee break

16:00 → 17:40 Nuclear structure

16:00 Toward lattice simulations of strongly-correlated nuclear systems with high-fidelity chiral interactions

Speaker: Dean Lee

16:20 Visualizing nuclear correlations: ab initio shapes of nuclei and application to 22Ne

Speaker: Benjamin Bally (TU Darmstadt)

16:45 The shape of 20Ne from low energy nuclear physics measurements

Speaker: Nico Orce

17:05 Discussion: Imaging nuclei in high-energy collisions

18:00 → 20:00 Reception

Tuesday 2 December

09:00 → 10:50 Hard Probes and nPDFs in Light-Ion Collisions

Convener: Dennis Perepelitsa (University of Colorado Boulder)

09:00 Status and perspectives of nPDFs for light-ions

Speaker: Petja Kalle Matias Paakkinen

09:20 Nuclear PDFs from the nCTEQ25 global analysis and potential impact of light ion collisions at the LHC

Speaker: Katrin Greve

09:35 No-quenching baseline computations for light-ion collisions

Speaker: Jannis Gebhard (Heidelberg University)

09:50 ALICE overview hard probes

Speaker: Florian Jonas (CERN)

10:05 ATLAS overview hard probes

Speaker: Anne Marie Sickles (Univ. Illinois at Urbana Champaign (US))

10:20 CMS overview hard probes

Speaker: Cristian Baldenegro (Massachusetts Inst. of Technology (US))

10:35 STAR / sPHENIX overview hard probes

Speaker: Sijie Zhang

10:50 → 11:20 Coffee break

11:20 → 12:20 Topical discussions

11:20 Discussion: Energy loss versus system size from an experimental point of view

11:50 Discussion: Centrality determination in light ions

12:20 → 14:00 Lunch break

14:00 → 15:30 Energy loss in light ion collisions

14:00 Light-Ion Suppression from pQCD Energy Loss with Small-System Corrections

Speaker: Cole Faraday

14:15 Energy loss predictions in the color-coherence framework

Speaker: Adam Takacs (Heidelberg University)

14:30 Leveraging light-ion collisions to eke out the path-length dependence of energy-loss

Speaker: Isobel Kolbé (University of the Witwatersrand (ZA))

14:45 Jet quenching and medium response for OO collisions in the hybrid model

Speaker: Arjun Srinivasan Kudinoor (Massachusetts Institute of Technology)

15:00 Early Colour-Coherence Effects in Jet Quenching

Speaker: Liliana Apolinario (LIP (PT))

15:15 Path length dependence of radiative energy loss

Speaker: Francois Arleo (Subatech, Nantes)

15:30 → 16:00 Coffee break

16:00 → 16:45 Energy loss in light ion collisions

16:00 Discussion: What have we learnt about hard probes by varying the system size?

Speakers: Carlota Andres (CPHT, Ecole polytechnique), William Horowitz (University of Cape Town), Yen-Jie Lee (Massachusetts Inst. of Technology (US))

16:45 → 17:45 SMOG2 & cosmic rays

16:45 Perspectives and opportunities for SMOG2

Speaker: Chiara Lucarelli (CERN)

17:00 Report from LHCf and cosmic showers

Speaker: Eugenio Berti (Universita e INFN, Firenze (IT))

17:15 Expected impacts of light-ion collisions on models of cosmic showers

Speaker: Felix Riehn (Technische Universitaet Dortmund (DE))

19:00 → 21:00 Workshop dinner

Fondue dinner; route: https://maps.app.goo.gl/ZVMBVZru5purpiGTA
Please register and pay on indico

Wednesday 3 December

09:00 → 10:10 Machine Performance and Science Cases for Future Ion Runs

Convener: Anthony Robert Timmins (University of Houston (US))

09:00 Overview of the planned R&D of future ions post-LS3 in the injector chain

Speaker: Maciej Slupecki (CERN)

09:20 Charting the Luminosity Capabilities of the CERN Large Hadron Collider with Various Nuclear Species

Speaker: Dr Roderik Bruce (CERN)

09:40 Beam transmutation in light-ion collisions

Speaker: John Jowett (GSI - Helmholtzzentrum fur Schwerionenforschung GmbH (DE))

09:55 The case of Nuclear Matrix Elements of 0νββ decay

Speaker: Giuliano Giacalone

10:10 → 10:40 Coffee break

10:40 → 12:00 Discussion on the 2026 Ion Run and Beyond

Convener: Dr Georgios Krintiras (The University of Kansas (US))

10:40 LHC performance in 2025 & what comes next

Speakers: Chiara Zampolli (CERN), Christopher Young (CERN)

10:50 Light ions with ALICE 3

Speaker: David Dobrigkeit Chinellato (Austrian Academy of Sciences (AT))

11:10 Looking for the path towards saturation at the LHC

Speaker: Christophe Royon (The University of Kansas (US))

11:20 Discussion

12:00 → 14:00 Lunch break

14:00 → 15:00 TH Colloqium: Light-Ion Collisions - Bridging Small and Large QCD Systems

The first oxygen–oxygen and neon–neon collisions at the LHC this July have opened a new frontier in exploring hot and dense QCD matter. These light-ion systems bridge the gap between proton–proton and heavy-ion collisions. Over the past decade, experiments have revealed intriguing but sometimes puzzling results: signals of elliptic flow appear even in proton–proton collisions, whereas clear signs of jet quenching remain absent in small systems. The recent pO, OO, and NeNe runs enable precision tests of heavy-ion models in intermediate-size systems. Light-ion collisions probe the critical regime where nuclear structure, perturbative QCD, and quark–gluon plasma physics intersect. I will discuss what the first light-ion data reveal about the structure of the colliding nuclei, the applicability of hydrodynamics, and the onset of partonic energy loss in small systems.

Speaker: Aleksas Mazeliauskas

Agenda