GPU-accelerated collision events, detector displays, and resonance hunting
Smash particles together fast enough and the energy turns into brand-new matter. This is how the Higgs boson was found.
Set the energy and press Collide! Notice that higher energy sprays out more tracks and heavier particles, and that no two events look alike.
Particle colliders are the world's most powerful microscopes. By smashing particles together at nearly the speed of light, we convert kinetic energy into new particles (E = mc²). The Large Hadron Collider at CERN collides protons at 13 TeV — recreating conditions a trillionth of a second after the Big Bang.
Watch two particle beams collide and produce a shower of new particles. Higher collision energy produces more and heavier particles. Each event is unique.
Press New Event and see where each particle stops in the detector layers. Look for the missing-energy arrow left by escaping neutrinos.
Modern detectors like ATLAS and CMS wrap concentric layers around the collision point. Each layer identifies different particle types: the tracker measures charged particle paths, the ECAL catches electrons and photons, the HCAL catches hadrons, and the muon chambers catch muons. Neutrinos escape undetected as "missing energy."
Run Auto Sweep, or click and drag on the plot, to scan the energy. Each sharp peak is a new particle being created.
The cross section σ(E) tells us how likely a reaction is at a given energy. Peaks in the cross section correspond to resonances — the creation of real particles like the J/ψ, Υ, and Z boson. Each peak follows the Breit-Wigner distribution.
Watch the events pile up in the histogram, using Speed to hurry them along. See if you can spot the Higgs bump near 125 GeV rising out of the background.
The Higgs boson was discovered in 2012 by looking for a tiny bump in the invariant mass distribution of photon pairs (H → γγ). Watch events accumulate and see if you can spot the signal emerging from the background.
Spot a mistake or have an idea?