N* program at CLAS
Description
The N* program is one of the major goals of CLAS experiments in Jefferson Lab and many outstanding results have been carried out. In this note, I will present some highlight recent measurements of nucleon resonance transition form factors from electro-production as the second resonances. The new pion electro-production data resolve a longstanding puzzle of the nature of the Roper resonance, and confirm the assertion of the symmetric constituent quark model of the Roper as the first radial excitation of the nucleon. The single pion electro-production data for high Q2 confirms the slow fall off of the S11(1535) transition form factor with Q2, and better constrain the branching ratios βNπ:βNη = 0.50:0.45. For the first time, the longitudinal transition amplitude to the S11(1535) was extracted from the ηπ+ data. Also, new results on the transition amplitudes for the D13(1520) resonance are presented showing a rapid transition from helicity 3/2 dominance seen at the real photon point to helicity 1/2 dominance at higher Q2.
Availability note (English)
Available from Nuclear Physics B - Proceedings Supplements; Volumes 207-208, pages 216-219 (Oct-Nov 2010)Additional details
Identifiers
Publishing Information
- Imprint Pagination
- 4 p.
- Report number
- JLAB-PHY--10-1139
Conference
- Title
- QCD 10 (25th Anniversary)
- Acronym
- 15. International QCD Conference
- Dates
- 28 Jun - 3 Jul 2010
- Place
- Montpellier (France)
INIS
- Country of Publication
- United States
- Country of Input or Organization
- United States
- INIS RN
- 42050267
- Subject category
- S72: PHYSICS OF ELEMENTARY PARTICLES AND FIELDS;
- Resource subtype / Literary indicator
- Conference, Non-conventional Literature
- Descriptors DEI
- BRANCHING RATIO; EXCITATION; FORM FACTORS; HELICITY; N-1440 BARYONS; NUCLEONS; PHOTONS; PIONS; QUANTUM CHROMODYNAMICS; QUARK MODEL; RESONANCE; TRANSITION AMPLITUDES
- Descriptors DEC
- AMPLITUDES; BARYONS; BOSONS; COMPOSITE MODELS; DIMENSIONLESS NUMBERS; ELEMENTARY PARTICLES; ENERGY-LEVEL TRANSITIONS; FERMIONS; FIELD THEORIES; HADRONS; MASSLESS PARTICLES; MATHEMATICAL MODELS; MESONS; N BARYONS; N*BARYONS; PARTICLE MODELS; PARTICLE PROPERTIES; PSEUDOSCALAR MESONS; QUANTUM FIELD THEORY
Optional Information
- Contract/Grant/Project number
- AC05-06OR23177
- Notes
- doi http://dx.doi.org/10.1016/j.nuclphysbps.2010.10.056
- Funding organization
- USDOE Office of Science (United States)
- Secondary number(s)
- DOE/OR--23177-1493