COLLIDER / MERIDIAN LABORATORY

MERIDIAN COLLIDER · RUN 88 · STABLE BEAMS

We collide protons so the universe has to answer.

Twenty-seven kilometres of superconducting ring beneath the Val Brenga. Two beams, forty million crossings a second — and somewhere in the debris, we think, a particle nobody has ever seen.

CLICK / TAP ANYWHERE — TRIGGER AN EVENT

EVENT READOUT — IP-2 (HALO)DAQ OK

EVT 0408 · E=13.1 TeV · 57 tracks · axion-9 candidate: no

EVT 0407 · E=12.8 TeV · 44 tracks · axion-9 candidate: no

01

The machine

SECT. A · CRYOGENICS NOMINAL

Under an alpine valley, two beams of protons travel a ring the length of a marathon at 99.999996% of the speed of light — one clockwise, one counter-clockwise. Where they cross, protons meet with the energy of two head-on freight trains packed into a space a trillion times smaller than a raindrop. Everything below is kept colder than deep space, so the magnets that steer the beams lose no energy at all.

Ring circumference
0.0kmBuried 90–480 m beneath the Val Brenga
Magnet temperature
0.0K−271 °C. Colder than the space between galaxies
Beam crossings
0million / sOf which ~1,200/s are kept for analysis
Superconducting magnets
0unitsEach one steers, none of them push
02

Four ways of seeing

SECT. B · CROSS-SECTIONS, SCHEMATIC

A collision lasts about a hundredth of a billionth of a billionth of a second. The detectors are how we replay it. Each is a camera built for a different question — hover or tab through the layers to see what each shell does.

HALO

IP-2 · GENERAL PURPOSE

An onion of instruments, 24 m across. If something new is made at Meridian, HALO is built to notice — this is where the axion-9 search lives.

VETRA

IP-4 · FORWARD SPECTROMETER

Looks down the beam instead of around it. VETRA watches particles that barely deflect — the shy ones — and times them to a trillionth of a second.

CASCADE

IP-6 · MISSING-ENERGY CAMERA

A 3,000-tonne stack of steel and scintillator that measures what isn't there. If energy leaves a collision unseen, CASCADE notices the hole it left.

ATRIUM

HALL 9 · AXION HALOSCOPE

The quiet one. No beam at all — a supercooled cavity listening for axion-9 drifting in from the galaxy, faint as a radio station one photon strong.

03

Experiments board

SECT. C · UPDATED 08 JUL 2026, 05:00 CET

Every programme at Meridian is public from day one. Data is embargoed for exactly ninety days — after that, anyone on Earth can download it.

04

The hunt for axion-9

SECT. D · 2.7σ AND CLIMBING

Four-fifths of the matter in the universe is missing. We can weigh it — galaxies spin as if held by something enormous and invisible — but nobody has ever caught a piece of it.

Axion-9 is our best guess: a particle so light that a billion of them would weigh less than a single electron, drifting through the valley, through the mountain, through you, right now. It almost never touches ordinary matter. Almost is the word this laboratory is built on.

In March 2026, the AXIA team found 14 collisions that look like axion-9 being born: two photons and a hole in the energy books, exactly where theory said to look. Fourteen events is a whisper, not a discovery — chance could fake it roughly once in two hundred tries. We need about forty more. At current beam intensity, the answer arrives in eleven months. You can watch the counter move on this page.

CANDIDATE FILE — A9

predicted mass
9.6 µeV — lighter than light itself, nearly
signature
2 photons + missing momentum
events needed
≈ 55 for discovery (5σ)
events so far
14 · significance 2.7σ
first proposed
Okonkwo & Brandt, 2019
if confirmed
dark matter has a name
05

Physicist in residence

SECT. E · COHORT 7 OPENS SOON

Four times a year, we hand a badge, a desk in the HALO control room, and full data access to someone who doesn't work here — an early-career physicist, a teacher, once a glaciologist who wanted to apply her avalanche statistics to particle showers. (It worked. She's on two papers.)

Residents take shifts, break things, fix them, and leave with their name in the logbook. No publication quota, no deliverables. The only requirement is a question you can't stop thinking about.

“I expected a cathedral. It's more like a ship — everything hums, everyone has a station, and the night shift makes the best coffee in the canton.”
— DR. IMKE FALLENIUS, RESIDENT, COHORT 5 · WROTE THE TRIGGER FILTER NOW CALLED "IMKE'S SIEVE"
  • DURATION6 weeks, underground & up
  • STIPEND€8,400 + housing in Brenga village
  • COHORT4 residents per season
  • NEXT DEADLINE3 October 2026
  • REQUIREMENTSOne page. One question.

Come stand 482 metres above a collision.

On open days we take you down: the lift, the tunnel that curves away farther than you can see, the control room where the event counter never stops. Children under 12 get their own dosimeter badge to keep. (It reads zero. That's the point — and the physicists will happily explain why.)

NEXT OPEN DAYS
SAT 05 SEP 2026 · 09:00–17:00 — RING & HALO CAVERN
SAT 03 OCT 2026 · 09:00–17:00 — RING & CASCADE HALL
AUTUMN OPEN WEEKEND · 24–25 OCT 2026 — ALL FOUR DETECTORS