Published December 1999 | Version v1
Journal article

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.