An event in particle physics describes one set of particle interactions occurring in a brief span of time, typically recorded together. Particle physics is a branch of Physics that studies the elementary constituents of Matter and Radiation, and the interactions between them In Particle physics, an elementary particle or fundamental particle is a particle not known to have substructure that is it is not known to be made At modern particle accelerators this refers to the interactions that occur as a result of one beam crossing inside a detector. A beam crossing in a Particle collider occurs when two packets of particles going in opposite directions reach the same point in space In experimental and applied Particle physics and Nuclear engineering, a particle detector, also known as a radiation detector, is a device used to