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 (770) and 0(1600) and a structure near the NN threshold are automatically generated. The obtained has a much larger width, whose signicance is explored. No evidence is found for a peak at the 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.
Nucleon time-like form factors below the NN threshold / Baldini, R; Dubnicka, S; Gauzzi, Paolo; Pacetti, S; Pasqualucci, E; Srivastava, Y.. - In: THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS. - ISSN 1434-6044. - 11:(1999), pp. 709-715. [10.1007/s100520050667]
Nucleon time-like form factors below the NN threshold
GAUZZI, Paolo;
1999
Abstract
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 (770) and 0(1600) and a structure near the NN threshold are automatically generated. The obtained has a much larger width, whose signicance is explored. No evidence is found for a peak at the 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
