https://doi.org/10.1140/epjc/s10052-013-2594-4
Regular Article - Theoretical Physics
Padé approximants and resonance poles
1
Institut für Kernphysik, Johannes Gutenberg-Universität, 55099, Mainz, Germany
2
Departamento de Física Teórica and Instituto de Física Teórica, IFT-UAM/CSIC Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain
* e-mail: masjuan@kph.uni-mainz.de
Received:
1
July
2013
Revised:
22
August
2013
Published online:
15
October
2013
Based on the mathematically well defined Padé theory, a theoretically safe new procedure for the extraction of the pole mass and width of a resonance is proposed. In particular, thanks to the Montessus de Ballore theorem we are able to unfold the second Riemann sheet of an amplitude to search for the position of the resonance pole in the complex plane. The method is systematic and provides a model-independent treatment of the prediction and the corresponding errors of the approximation. Likewise, it can be used in combination with other well-established approaches to improve future determinations of resonance parameters.
© Springer-Verlag Berlin Heidelberg and Società Italiana di Fisica, 2013
