Year: 2009
Type: article
Abstract: 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 N π and β N η. 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.
Source: Chinese Physics C
Author: CLAS collaboration
Institution: Thomas Jefferson National Accelerator Facility
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2153181004