Stability of the [Formula Presented] ratio at the T-matrix pole

Physical Review C - Nuclear Physics

Volumn 59, Issue 3, 1999, Pages 1810-1812

  Workman, Ron L ^a   Arndt, Richard A ^a  

^a VIRGINIA POLYTECHNIC INSTITUTE AND STATE UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0033244076     PISSN: 05562813     EISSN: 1089490X     Source Type: Journal    
DOI: 10.1103/PhysRevC.59.1810     Document Type: Article

References (25)

1. G. Blanpied, Phys. Rev. Lett. 76, 1023 (1997)
2. Phys. Rev. Lett.R. Beck, 79, 4337 (1997).
3. A. J. Buchmann, E. Hernández, and A. Faessler, Phys. Rev. C 55, 448 (1997).
4. I. G. Aznauryan, Phys. Rev. D 57, 2727 (1998)
5. T. Sato and T.-S. H. Lee, Phys. Rev. C 54, 2660 (1996). Both of these works extract values for the (Formula presented) amplitude in approximate agreement with quark model predictions. However, Aznauryan considers her result to be dressed, while the Sato and Lee value is clearly for a bare amplitude.
6. O. Hanstein, D. Drechsel, and L. Tiator, Nucl. Phys. A632, 561 (1998)
7. O. HansteinD. DrechselL. TiatorPhys. Lett. B 385, 45 (1996);L. Tiator, D. Drechsel, and O. Hanstein, in Proceedings of the 4th CEBAF/INT Workshop on(Formula presented) Physics, edited by T.-S.H. Lee and W. Roberts (World Scientific, Singapore, 1997), p. 296.
8. R. A. Arndt, I. I. Strakovsky, and R. L. Workman, Phys. Rev. C 56, 577 (1997).
9. R. M. Davidson and N. C. Mukhopadhyay (private communications).
10. Th. Wilbois, P. Wilhelm, and H. Arenhövel, Phys. Rev. C 57, 295 (1998)
11. Phys. Rev. CP. Wilhelm, Th. Wilbois, and H. Arenhövel, 54, 1423 (1996).
12. An extra factor of inverse pion momentum is required in (Formula presented) to account for the threshold behavior of (Formula presented) The Born terms have the correct threshold behavior and are given in many references.
13. See for example, F. A. Berends, A. Donnachie, and D. L. Weaver, Nucl. Phys. B95, 1 (1967). The Born couplings were taken from our global analysis and not searched in this study.
14. G. F. Chew, M. L. Goldberger, F. E. Low, and Y. Nambu, Phys. Rev. 106, 1345 (1957).
15. R. Omnès, Nuovo Cimento 8, 316 (1958)
16. N. Muskhelishvili, Singular Integral Equations (Nordhoff, Groningen, 1953).
17. R. M. Davidson, N. C. Mukhopadhyay, and R. S. Wittman, Phys. Rev. D 43, 71 (1991).
18. See, for example, S. N. Yang, J. Phys. G 11, L205 (1985)
19. S. Nozawa, B. Blankleider, and T.-S. H. Lee, Nucl. Phys. A513, 459 (1990)
20. P. Christillin and G. Dillon, J. Phys. G 22, 1773 (1996).
21. R. M. Davidson, L. Tiator, and A. Sandorfi (private communications). See also Refs. 14.
22. These databases were constructed in conjunction with R. M. Davidson, N. C. Mukhopadhyay, and M. S. Pierce in order to gauge the model and database dependence of the (Formula presented) ratio. They differ mainly in the inclusion/exclusion of certain precise wide-angle Bonn cross section measurements [H. Genzel, Z. Phys. 268, 43 (1974)
23. Z. Phys.G. Fischer, 245, 225 (1971)]. As these are “test databases,” the quantitative (Formula presented) results given here should not be taken in place of other determinations. Communications with R. Beck on this point are acknowledged.
24. The contribution from Born terms times (Formula presented) can be compared to the phenomenological multipole amplitudes using the SAID program (Telnet: said.phys.vt.edu, userid: said).
25. There would be a sharper correspondence between the real part of the T-matrix pole ratio and the (real) K-matrix value if (Formula presented) and (Formula presented) were energy independent. See L. Resnick, Phys. Rev. D 2, 1975 (1970) for an interesting and related study exploring the consequences of energy-independent Born terms in the Muskhelishvili-Omnès formalism.