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in the quantum theory of collisions, a quantity which numerically describes the collisions of microparticles. A beam of particles (with a determined impulse) which is falling on a target scatters, and the particles can deflect in any direction. The relative number of particles scattering at different angles to the primary direction of the beam depends on the particular law governing the interaction of the scattered particles with the target particles. The probability of a particle’s scattering at a given angle is determined by the scattering amplitude—or by the modulus square of the scattering amplitude, to be exact.
V. P. PAVLOV