CMS Collaboration

At the Large Hadron Collider, protons smash into each other like two trucks full of confetti. The debris, dozens of new particles, scatters in all directions. The detector records their tracks, and then the real work begins: piecing together a complete picture of the collision from those tracks. Previously, this was done by a set of rules devised by physicists.

In the CMS detector at the Large Hadron Collider, protons smash together with enormous energy, producing a shower of particles. Most of them decay almost instantly, right at the collision point.

At the Large Hadron Collider, physicists accelerate protons to nearly the speed of light and smash them together. Usually, the protons themselves take part in such collisions, but sometimes they pass close by without touching, and it is their electric fields that interact.

In 2018, the Large Hadron Collider ran a special data-taking campaign: the CMS detector captured proton collisions at breakneck speed to collect ten billion particles containing a beauty quark.

At the center of a collision between two lead nuclei, a tiny fireball is born for an instant — matter so hot that protons and neutrons melt, and quarks and gluons swim freely in this 'soup.' This soup is called quark–gluon plasma. It existed in the first microseconds after the Big Bang, and now it is recreated in accelerators.

When two protons collide at enormous speed, a narrow beam of particles (a jet, like the spray from a stone thrown into water) shoots out from the point of impact. In collisions of heavy lead nuclei, things are more complicated: a hot cloud forms inside, which interferes with the jet's straight flight.

In the 2010s, physicists working at the Large Hadron Collider learned to create in the lab a substance that doesn't exist in the ordinary world.

The Large Hadron Collider doesn't just smash protons: it also collides entire atomic nuclei. When two nuclei smash together at tremendous speed, they create a tiny blob of matter so hot that protons and neutrons melt into a 'soup' of quarks and gluons.

In 2017, protons at the Large Hadron Collider collided with an energy of 5.02 TeV. The CMS detector recorded these collisions, and among billions of events, physicists hunted for a rare occurrence: the production of a single top quark without its antiparticle.

When two lead nuclei collide at tremendous speed, a cloud of scorching matter is born for an instant — denser and hotter than the center of the Sun. Through this cloud fly jets of particles: narrow, laser-like beams knocked out by the impact. The CMS detector captures their tracks and shows how the jets change as they fight through the hot 'fog'.

When a W boson, the particle that carries the weak force, decays into a quark and an antiquark, these two fragments fly off in nearly the same direction at the collider's immense speeds.

Colliding two lead nuclei at the Large Hadron Collider is like throwing two hefty bags of marbles at each other. Usually, the marbles scatter in all directions, but sometimes one bag passes so close that the marbles don't collide: they just exchange glances.

At the Large Hadron Collider, protons collide, and from the flash dozens of particles are born. Among them may be traces of rare processes — for example, the decay of a Standard Model Higgs boson into two W bosons. But these particles fly apart so quickly that their tracks merge into a single wide jet.

From 2016 to 2018, at the Large Hadron Collider at CERN, protons collided at energies of 13 teraelectronvolts, as if two peas were accelerated to speeds where their impact spawns a whole swarm of new particles.

When two particles fly at almost the same speed in the same direction, their signals in the detector merge, like two voices in unison. Telling a duet from a soloist is an art in itself.

In the CMS detector at the Large Hadron Collider, protons accelerated to nearly the speed of light collided. Among billions of such collisions, physicists searched for a rare signature: the production of a single heavy particle that immediately decays into a W boson and a b quark.

At the Large Hadron Collider, protons collide billions of times per second, and only once in a trillion collisions does a pair of Standard Model Higgs bosons (the particles responsible for the mass of everything) emerge. In the CMS experiment, physicists hunted for exactly such events.

A noisy train station at rush hour. Thousands of people hurry past, voices merging into a dull roar. Somewhere in the crowd, two people try to shake hands with a special, barely visible gesture. Spotting such a handshake is nearly impossible.

A firework bursts, and one point explodes into four sparks at once. That's how the Z boson, the particle that carries the weak force, behaves when it decays into four charged leptons (electrons or muons). The process is extremely rare: for every million Z bosons produced, only about five decay this way.

The Higgs boson is like a tuning fork that rings at a strictly defined note. But physicists have learned to hear it even when the note is off — in the so-called 'off-shell' region. It was there, in the data from the CMS detector, that answers were hiding about what the Higgs mechanism is really made of.