annihilation cross-section

The annihilation cross-section is a measure used in particle physics to describe the likelihood of two particles colliding and annihilating each other, resulting in the production of other particles. It quantifies how effectively this interaction occurs and is expressed in area units, representing a "target" that the incoming particles "hit." A larger cross-section indicates a higher probability of annihilation, while a smaller one means it's less likely. This concept helps scientists understand and predict particle interactions in experiments and in the universe, such as how matter and antimatter behave.