eta-c particle

音节分段：e.ta-c particle; AHD音标：3“t…-s?“, ?“t…-; 国际音标：6e!t*6si8, 6i8t*-; 美国音标：6et*6si, 6it*-; An electrically neutral meson having a mass 5,832 times that of the electron and a mean lifetime of approximately 3.1 × 10-22 seconds.