Naslov
The importance of inelastic channels in eliminating continuum ambiguities in pion-nucleon partial wave analyses

Autori
Alfred Švarc

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Proceedings of the Workshop on the Physics of Excited Nucleons Nstar2005 / Simon Capstick, Volker Crede, Paul Eugenio - Singapur : London : München : Ženeva : Tokyo : Hong Kong : Taipei : Peking : Šangaj : Tianjin : Chennai : World Scientific Publishing, 2006, 37-47

Skup
NSTAR 2005 (The Physics Of Excited Baryons)

Mjesto i datum
Tallahassee (FL), Sjedinjene Američke Države, 12.10.2005. - 15.10.2005

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
coupled channel partial wave analysis; continuum ambiguities

Sažetak
Single channel, single energy partial wave analyses (SE_PWA) are from the first principles non-unique in the inelastic region if only data from elastic channels are used, so we in details discuss mechanisms how the problem is eliminated in pion-nucleon scattering. The "continuum ambiguities" puzzle has been extensively discussed since early 1970es [1-3], and two major mechanisms for solving the problem have been suggested: either to ensure the continuity of Argand diagrams by imposing the T-matrix t-channel analyticity (Karlsruhe-Helsinki, VPI/GWU) or to restore the unitarity loss in the kinematical regime where the inelastic channels are successively opened by replacing the standard single channel PWA by the coupled channel formalism (CMB, Zagreb, Kent, Pittsburgh/ANL, Giessen). In both approaches the insufficiency of the single channel data is eliminated by introducing additional constraints using the data from other channels. The importance and physical meaning of the second approach is presented in details, and the significance of inelastic channels for the uniqueness of the partial wave analysis is discussed. The outline of the procedure for utilizing the coupled channel formalism to perform the search for the minimal number/full set of T-matrix poles in the complex energy plane, which connect the quark model predictions to experimental reality, is proposed. The appearance of new, additional resonances unneeded in the sole elastic channel is demonstrated. REFERENCES: 1. R. Atkinson and M. de Roo, Phys. Lett. B148 (1984) 363. 2. D. Atkinson, Phase-Shift Ambiguities, in Hadrons-93, Proceedings of the International workshop on soft physics, Novi Svit, Crimea (1993) pages 6-17 (http://www-th.phys.rug.nl/~atkinson/procrim.ps). 3. Bowcock, J. E. ; Burkhardt, H.: Principles and problems of phase-shift analysis, Reports on Progress in Physics, Volume 38, Issue 9, pp. 1099-1141 (1975).

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA