A drawing of a particle collision inside a barrel-shaped detector: curved tracks fan out from the centre, two sprays of particles hit blocks of the calorimeter, and two long tracks run out through the outer chambers

Independent tracker · not CERN, not Mistral

Tracking Flare, the physics AI from CERN and Mistral

On 15 October 2026 CERN and Mistral AI agreed to build a foundation model for collider physics, a Large Physics Model that learns from billions of simulated LHC collisions instead of text. We follow it from announcement to first paper, and keep what is known apart from what isn't.

Status
Statement of intent, signed 15 October 2026
Learns from
Billions of simulated LHC collisions
Papers
None yet
Release date
Not announced
Open weights
Not announced

Checked 17 October 2026 against CERN's release and Mistral's news page.

A model trained on collisions, not words

Large language models learn by reading text. Flare would learn the same way from particle collisions: billions of them, simulated at CERN's Large Hadron Collider, until it has a general sense of what a collision looks like inside a detector. Then it gets tuned for each job.

CERN names four jobs: reconstructing collisions, identifying particles, flagging unexpected signals, and assessing designs for future detectors (CERN's release). Today each of those uses its own chain of specialised algorithms.

How a Large Physics Model works · What reconstruction is

Today

  1. Detector hits
  2. Track finding
  3. Vertices
  4. Calorimeter clusters
  5. Particle flow
  6. Particle ID
  7. Jets and physics objects

Each step is its own algorithm, tuned by its own team.

The plan

  1. Detector hits
  2. One pretrained model, learned from billions of simulated collisions
  • Reconstruction
  • Particle identification
  • Unexpected signals
  • Detector design studies

The same model tuned for each job.

Our own simplified sketch. The steps differ between experiments, and CERN hasn't said how Flare will be built.

Latest on the timeline

  1. · Flare

    Reuters reports the model as "Flare"

    Reuters' headline names it Flare and quotes a CERN spokesperson: the same idea as the large language models behind generative AI, trained on collision data instead of text.

    Source: Reuters (via KSL)

  2. · Flare

    CERN and Mistral sign a statement of intent

    A long-term partnership whose first aim is a pretrained Large Physics Model for collider physics, trained on billions of simulated proton-proton collisions. No budget, timeline or licence is given.

    Source: CERN

  3. A "prompting" model maps any reconstruction step to any other

    One tokenised model takes any mix of tracks, calorimeter cells and particles and predicts the others. It is the closest published idea to learning the whole reconstruction chain at once.

    Source: arXiv 2609.31862

  4. The LHC stops for its long upgrade

    Run 3 physics was planned to end on 29 June 2026, starting Long Shutdown 3, the works that turn the LHC into the High-Luminosity LHC.

    Source: CERN

The full timeline, with what's expected next

Why CERN wants it

  • 1 EBof LHC data stored so far, a million terabytes
  • 40Mbunch crossings a second inside the LHC
  • ~10×the LHC's design collisions, once it becomes the High-Luminosity LHC
  • 2030when the upgraded machine is due to start

Sources: CERN, CMS, HL-LHC media kit, CERN's schedule. The data problem in full