Counting the invisible: CERN explains how collisions are counted and particles predicted
How many collisions does a particle accelerator produce – and how many Higgs bosons can be expected? The second episode of CERN's video series "Particle Collisions" explains.
Photo: Maximilien Brice (CERN) / Wikimedia Commons, CC BY-SA 3.0 (cropped and resized)
Video: YouTube · CERN · youtube.com
The European Organization for Nuclear Research CERN near Geneva released the second episode of its explainer series "Particle Collisions" on 16 October. Titled "Counting the invisible", it deals with how many collisions a particle accelerator produces and how physicists predict how many Higgs bosons, Z bosons or other particles they can expect in an experiment.
The focus is on two quantities: luminosity and cross-section. According to CERN, together they connect the accelerator to the physics it produces. The video also explains why particle physicists measure their data in "inverse femtobarns".
The first episode, released on 9 October, asked why so many collisions are needed at the Large Hadron Collider (LHC), where millions happen every second. It dealt with randomness in particle physics and how rare the events physicists look for are.