Summary
Using fairly general unitarity and analyticity arguments, we discuss how a degenerate multiplet of states mixes and splits in mass because of their coupling to common channels. Largely independently of what the input parameters are a simple picture emerges: i) the physical resonances have vastly different widths, ii) the narrowest resonances couple weakly to the large phase-space channels, iii) the mass splittings are correlated to the widths such that the narrower the resonance the heavier it is in mass. A numerical example is given.
Riassunto
Mediante corretti argomenti generali di unitarietà ed analiticità, si discute come un multipletto degenere di stati si mescola e si scinde in massa a causa degli accoppiamenti degli stati a canali comuni. Completamente indipendentemente da ciò che sono i parametri d'entrata, si forma un quadro molto semplice: i) le risonanze fisiche hanno ampiezze molto diverse, ii) le risonanze più strette si accoppiano debolmente agli ampi canali dello spazio delle fasi, iii) le separazioni di massa sono correlate alle ampiezze in modo che più stretta è la risonanza, più pesante è in massa. Si dà un esempio numerico.
Резюме
Используя общие свойства унитарности и аналитичности, мы обсуждаем, как происходит смешивание и расщепление по массе вырожденного мультиплета состояний из-за их связи с обычными каналами. Независимо от исходных параметров появляется простая картина: 1) физические резонансы имеют различные ширины, 2) наиболее узкие резонансы слабо связаны с каналами с большим фазовым пространством, 3) массовое расщепление коррелирует с щиринами так, что более узкому резонансу отвечает больщая масса. Рассматривается численный пример.
Similar content being viewed by others
References
A. Katz andH. J. Lipkin:Phys. Rev. Lett.,7, 44 (1963).
N. A. Törnqvist:Phys. Lett.,69 B, 193 (1977).
C. Bemporard:Proceedings of the 1977 International Conference on Lepton and Photon Interactions at High Energies (Hamburg, 1977), p. 165; andF. Laplamche:Proceedings of the 1977 International Conference on Lepton and Photon Interactions at High Energies (Hamburg, 1977), p. 189.
See,e.g., review byK. Gottfried:Proceedings of the 1977 International Conference on Lepton and Photon Interactions at High Eenergies (Hamburg, 1977), p. 667.
See,e.g., review byA. de Rujula andR. L. Jaffe: talk at theMeson Spectroscopy Conference Northeastern University, August 1977, Harward preprint (1977).
G. F. Chew:States of baryonium within the hadron family, invited talk at the3rd European Symposium on Antinucleon-Nucleon Interactions (Stockholm, July 1976), preprint LBL-5391;H.-M. Chan andH. Högaasen:Phys. Lett.,72 B, 121 (1977) and Rutherford Laboratory preprint RL-77-121/A;M. R. Pennington: CERN preprint TH 2457.
F. Gliozzi:Lett. Nuovo Cimento,4, 1160 (1970);R. Odorico:Phys. Lett.,61 B, 263 (1976);Phys. Rev. D,15, 1384 (1977).
R. Kinnunen andN. Törnqvist: Helsinki preprint HU-TFT-78-7;H. J. Lipkin: Fermilab-Pub-77/84-THY.
F. Renard:Phys. Lett.,60 B, 55 (1975).
Author information
Authors and Affiliations
Additional information
To speed up publication, the author of this paper has agreed to not receive the proofs for correction.
Supported by the Academy of Finland.
Traduzione a cura della Redazione.
Переведено редакцией.
Rights and permissions
About this article
Cite this article
Törnqvist, N.A. A dynamical model for narrow resonances. Nuov Cim A 46, 633–641 (1978). https://doi.org/10.1007/BF02776977
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF02776977