Nucleon time-like form factors below the NN threshold
- 1. Istituto Nazionale di Fisica Nucleare, Frascati (Italy). Lab. Nazionale di Frascati
- 2. Ist. of Physics, Slovak Acad. of Sciences, Bratislava (Slovakia)
- 3. Dipartimento di Fisica dell'Universita and INFN, Roma ''La Sapienza'' (Italy)
- 4. Dipartimento di Fisica dell'Universita and INFN, Perugia (Italy)
Description
The nucleon magnetic form factors in the unphysical region, i.e., for time-like Q2 but below the NN threshold, have been obtained by means of dispersion relations in a model-independent way, without any bias towards expected resonances. Space-like and time-like data have been employed, along with a regularization unfolding method to solve the integral equation. Remarkably, resonance structures with peaks for the ρ(770) and ρ'(1600) and a structure near the NN threshold are automatically generated. The obtained ρ has a much larger width, whose significance is explored. No evidence is found for a peak at the φ mass, in spite of the expectation that such a peak exists when there is a sizeable polarized ss content in the vector current of the nucleon. (orig.)
Additional details
Publishing Information
- Journal Title
- European Physical Journal. C
- Journal Volume
- 11
- Journal Issue
- 4
- Journal Page Range
- p. 709-715
- ISSN
- 1434-6044
INIS
- Country of Publication
- Germany
- Country of Input or Organization
- Germany
- INIS RN
- 32017273
- Subject category
- S72: PHYSICS OF ELEMENTARY PARTICLES AND FIELDS;
- Resource subtype / Literary indicator
- Numerical Data
- Descriptors DEI
- DISPERSION RELATIONS; ELECTROMAGNETIC FORM FACTORS; NUCLEONS; PARTICLE STRUCTURE; PARTICLE WIDTHS; RHO-770 MESONS; THEORETICAL DATA
- Descriptors DEC
- BARYONS; BOSONS; DATA; ELEMENTARY PARTICLES; FERMIONS; FORM FACTORS; HADRONS; INFORMATION; MESONS; NUMERICAL DATA; PARTICLE PROPERTIES; VECTOR MESONS
Optional Information
- Notes
- 31 refs.