Antiprotons: Bounce or Annihilate?
The antiproton is the mirror twin of the proton: same mass, but negative charge. When it hits matter, it usually annihilates instantly — disappearing in a burst of energy upon colliding with an atomic nucleus.
Three Protons Detected Together for the First Time
Three billiard balls scatter across the table after a strike: their trajectories depend only on the initial push. But in the world of atomic nuclei, things are more complex: particles sense each other on the fly, even if they are not bound together. For a long time, physicists could only measure pairwise interactions, while what happens when three meet remained behind the scenes.
When a Disease Wave Decides Its Own Speed
A disease outbreak is like a wildfire: the fire runs through dry grass, and its speed depends on wind and humidity. But an infection has its own 'wind'—how often people infect each other. When this rate changes along with the fraction of already infected, the epidemic wave can behave differently.
How Mass and Charge Swap Roles in a Multidimensional World
A carousel doesn't just spin you around in a circle — with each revolution, it also slightly screws itself into the ground. This corkscrew-like motion is the essence of the NUT charge, a special property of spacetime that physicists have been studying since the mid-20th century.
Top Quarks Stick Together Like Oil Droplets in Soup
Oil droplets in boiling broth usually scatter apart, but if you bump them together very slowly, they may stick for a moment. Something similar happens with top quarks — the heaviest known building blocks of matter.
Cosmic Showers: How Protons Paint a Portrait of the Atmosphere
Cosmic rays are particles that arrive from deep space. When such a particle hits the atmosphere, it triggers a whole shower of new particles, like a billiard ball breaking a rack, sending balls scattering in all directions. To predict what such a shower will look like, we need to know how the primary particle interacts with the nuclei of air atoms.
The Invisible Nudge: How Neutrinos Strike the Nucleus
A tiny ghostly particle zips through a piece of germanium. Usually it leaves no trace, but sometimes, like a billiard ball, it smacks into an atom's nucleus. The nucleus recoils, and that jolt can be detected. At Oak Ridge National Laboratory, the Ge-Mini detector caught such recoils for two years.
Neutrinos are the most elusive of known particles.
Top Quark Caught in a Rare Solo Dance
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.
Cosmic Billiards: How Particle Showers Are Born
Somewhere above our heads, every second, a proton accelerated to energies millions of times greater than those at the Large Hadron Collider slams into the atmosphere. It strikes an air molecule, and a cascade is born — a wide atmospheric shower of thousands of particles.
Top Quark Weighed at the Large Hadron Collider
Inside the Large Hadron Collider, protons are accelerated to nearly the speed of light and smashed head-on. At the collision point, a burst of energy is born for an instant, from which new particles can emerge. One of the heaviest is the top quark.
How a Pair of Particles Bounces Off a Wall
Two particles cling to each other like climbers on the same rope and fly toward a wall. When they hit, will they bounce off together, or will the rope snap? What does it depend on? Physicists considered the simplest case: everything happens on a single line, the particles attract only when they occupy the same point, and the wall is perfectly rigid.