摘要: Λ_c⁺重子家族存在一个疑难，也就是重夸克有效理论预言的轨道角动量为L=2的多重态中J^P=3/2⁺的态在实验上是缺失的，而且已发现的Λ_c（2765）⁺和Λ_c（2940）⁺的J^P量子数仍然未知。在本工作中，我们使用双夸克图像计算了重子的质量，研究了Λ_c（2765）⁺和Λ_c（2940）⁺的可能归类以及仍缺失的具有L=2和J^P=3/2⁺量子数的Λ_c⁺态，进而指出Λ_c（2880）⁺的峰结构中实际上已经包含了L=2、J^P=3/2⁺这一缺失态，并建议Λ_c（2765）⁺和Λ_c（2940）⁺的量子数应分别为2S（1/2⁺）和2P（1/2^-）。


There is a puzzle in the Λ_c⁺ family, i.e., one member with J^P=3/2⁺ is missing in a L=2 multiplet which the heavy quark effective theory predicts, and J^P's of Λ_c(2765)⁺ and Λ_c(2940)⁺ are unknown. Using a light diquark picture to calculate baryon masses, we study possible assignments of two Λ_c's with unknown J^P and the missing Λ_c⁺ with 3/2⁺ for L=2, and we find the most probable possibility that the peak corresponding to Λ_c(2880)⁺ actually includes a missing member with spin 3/2⁺ for L=2 and that quantum numbers of Λ_c(2765)⁺ and Λ_c(2940)⁺ are 2S(1/2⁺) and 2P (1/2^-), respectively.