The Start of the 2026 Heavy-Ion Run | #AskAPhysicist

Why It Matters

Understanding the quark‑gluon plasma deepens knowledge of the universe’s birth and could uncover physics beyond the Standard Model, influencing future high‑energy research investments.

Key Takeaways

• LHC switches from proton to lead-ion collisions for research.
• Aim: recreate conditions 1 microsecond after Big Bang.
• Three‑week heavy‑ion run precedes Run 4 upgrade schedule at LHC.
• Detectors upgraded to handle increased collision rates and data volume.
• New analyses could uncover subtle variations in fundamental force measurements.

Summary

The Large Hadron Collider began its 2026 heavy‑ion program, replacing proton beams with lead ions for the first time in years.

By colliding lead nuclei at unprecedented energies, scientists aim to reproduce the quark‑gluon plasma that existed roughly one microsecond after the Big Bang. The three‑week run will be followed by the start of Run 4, during which the accelerator will be upgraded to increase the collision frequency, and the experiments will receive hardware enhancements to cope with the higher data throughput.

CERN physicists highlighted that the conditions mirror a “soup of constituent particles” that melted matter in the early universe, and they expect even tiny deviations in previously measured quantities to reveal new aspects of the strong and electroweak forces.

If successful, the data could refine the Standard Model, guide future collider designs, and cement the LHC’s role as the premier laboratory for probing the fundamental structure of matter.

Original Description

What’s going on at the #LHC? 🤔

While the Large Hadron Collider mostly collides protons, once a year it collides heavy ions – such as lead nuclei – a key ingredient for recreating the extreme conditions of the early #Universe.

Hear from Silvia Pisano, Run Coordinator at the ALICE Experiment, about this year’s heavy-ion run at the LHC, and what’s happening after it.

The run will conclude with a two-week high-intensity test, which will probe the LHC’s behaviour under conditions closer to those expected at the #HiLumiLHC.

#AskAPhysicist #LHCRun3