Jaffe与Wilczek双夸克模型中的负宇称五夸克态(英文)  

J^P=(1^-)/2 Pentaquarks in Jaffe and Wilczek's Diquark Model

作　　者：张翱[1] 刘言锐[1] 黄鹏志[1] 邓卫真[1] 陈晓林[1] 朱世琳[1] 

机构地区：[1]北京大学物理学院理论物理研究所,北京100871

出　　处：《高能物理与核物理》2005年第3期250-257,共8页High Energy Physics and Nuclear Physics

基　　金：国家自然科学基金 (10 3 75 0 0 3 )资助~~

摘　　要：如果Jaffe与Wilczek关于Θ+5五夸克态的双夸克图像是正确的话 ,那就应该存在负宇称的五夸克SU(3)八重态与单态 ,其中两个双夸克间没有轨道激发 .这些态比Θ+5质量低 ,与传统夸克模型中的由三夸克构成的重子的轨道激发质量接近 .我们计算了这些负宇称态的质量与磁矩 ,用手征有效拉氏量讨论了他们可能的强衰变模式和选择定择 ,发现有两个态可能比较窄 .我们建议实验上寻找这九个额外的负宇称态 .如果将来的实验确实发现了这些态 ,那是对Jaffe与Wilczek双夸克模型的直接验证 .否则 ,应该重新评估Jaffe与Wilczek的双夸克图像甚至抛弃这个模型 .If Jaffe and Wilczek's diquark picture for Θ5+ pentaquark is correct, there should also exist a SUF(3) pentaquark octet and singlet with no orbital excitation between the diquark pair, hence Jp =-/2. These states are lighter than the Θ5+ anti-decuplet and lie close to the orbitally excited (L = 1) three-quark states in the conventional quark model. We calculate their masses and magnetic moments and discuss their possible strong decays using the chiral Lagrangian formalism. Among them two pentaquarks with nucleon quantum numbers may be narrow. Selection rules of strong decays are derived. We propose the experimental search of these nine additional Jp = -/2 baryon states. Especially there are two additional JP = -/2 Λ baryons around Λ(1405). We also discuss the interesting possibility of interpreting Λ(1405) as a pentaquark. The presence of these additional states will provide strong support of the diquark picture for the pentaquarks. If future experimental searches fail, one has to re-evaluate the relevance of this picture for the pentaquarks.

关 键 词：五夸克态 双夸克 轨道激发 磁矩 手征有效拉氏量 衰变模式 

分 类 号：O572.33[理学—粒子物理与原子核物理]