beta particle
noun [ C ] physics specialized uk/ˈbiː.tə ˌpɑː.tɪ.kəl/ us/ˈbeɪ.t̬ə ˌpɑːr.t̬ə.kəl/
ß粒子（在原子放射性衰变中产生的一种粒子，带一个正电荷或负电荷）
an extremely small piece of matter with a positive or negative electric charge, produced when a radioactive atom is broken down