6533b7dafe1ef96bd126e285

RESEARCH PRODUCT

Pole positions and residues from pion photoproduction using the Laurent-Pietarinen expansion method

H. OsmanovićLothar TiatorJ. StahovRon L. WorkmanAlfred ŠVarcM. Hadžimehmedović

subject

PhysicsNuclear and High Energy PhysicsParticle physicsNuclear Theorybaryon resonances ; poles ; Laurent+Pietarinen expansionSeries (mathematics)Laurent seriesNuclear TheoryFOS: Physical sciencesParticle Data GroupNuclear Theory (nucl-th)High Energy Physics - PhenomenologyHigh Energy Physics - Phenomenology (hep-ph)PionAmplitudePosition (vector)High Energy Physics::ExperimentNuclear ExperimentNucleonMultipole expansion

description

We have applied a new approach to determine the pole positions and residues from pion photoproduction multipoles. The method is based on a Laurent expansion of the partial wave T-matrices, with a Pietarinen series representing the regular part of energy-dependent and single-energy photoproduction solutions. The method has been applied to multipole fits generated by the MAID and GWU/SAID groups. We show that the number and properties of poles extracted from photoproduction data correspond very well to results from $\pi$N elastic data and values cited by Particle Data Group (PDG). The photoproduction residues provide new information for the electromagnetic current at the pole position, which are independent of background parameterizations, as opposed to the Breit-Wigner representation. Finally, we present the photo-decay amplitudes from the current MAID and SAID solutions at the pole, for all four-star nucleon resonances below W=2 GeV.

yearjournalcountryeditionlanguage
2014-04-06Physical Review C
https://doi.org/10.1103/physrevc.89.065208