few-body system
Technical term in physics referring to a system with a small number of interacting particles or bodies.
The quantum mechanical behavior of few-body systems shows characteristics different from many-body systems.
多体系 refers to a many-body system, while 少数多体系 specifically denotes a system with only a few bodies.
Compound of 少数 (few) + 多体 (many-body) + 系 (system), a direct translation of the English term 'few-body system'.