The N~* physics program at Jefferson Lab

摘要：

Recent measurements of nucleon resonance transition form factors with CLAS at Jefferson Lab are discussed. The new data confirm the assertion of the symmetric constituent quark model of the Roper as the first radial excitation of the nucleon. The data on high Q~2 nπ~+ production better constrain the branching ratios β_(Nπ) and β_(Nη). For the first time, the longitudinal transition amplitude to the S_(11)(1535) was extracted from the nπ~+ data. Also, new results on the transition amplitudes for the D_(13)(1520) resonance are presented showing a rapid transition from helicity 3/2 dominance seen at the real photon point to helicty 1/2 dominance at higher Q~2.I also discuss the status of the search for new excited nucleon states.

关键词： nucleon resonances transition form factors NA transition Roper magnetic dipole

作者: Volker D.Burkert

作者单位: Jefferson Laboratory 12000 Jefferson Avenue,Newport News,VA23606,USA

会议类型: 国际会议

会议名称: The 12th International Workshop on the Physics Ezcited Nucleon(2009核子共振态物理国际研讨会)

会议地点: 北京

会议语种:英文

页码: 1043-1050

在线出版日期: 2009-04-19（万方平台首次上网日期，不代表论文的发表时间）