Speaker
Robert Kaminski
(Institute of Nuclear Physics PAN)
Description
Recent works on the pion-pion scattering amplitudes done with use of one-subtracted dispersion relations [1] led to large modification of the f0(500) parameters, especially its width [2].
Immediately it led to long waited significant changes in the Particle Data Group Tables (Particle Listings and "Note on scalar mesons below 2 GeV" in [3]).
Such changes resulted in the need to redefine a number of amplitudes used in the theoretical and experimental works.
Sometimes, however, their authors doubt the necessity of introducing such changes and even question correctness of analyses confirming new parameters f0(500). Making example of reanalysis of such amplitudes and showing why dispersion relations with imposed crossing symmetry need narrower f0(500) one can easily once again prove the validity of the changes in the f0(500) parameters.
[1] "The Pion-pion scattering amplitude. IV: Improved analysis with once subtracted Roy-like equations up to 1100 MeV",
R. Garcia-Martin, R. Kaminski, J. R. Pelaez, J. Ruiz de Elvira and F.J. Yndurain, Phys. Rev. D83, 074004 (2011)
[2] "Precise determination of the f0(600) and f0(980) pole parameters from a
dispersive data analysis"
R. Garcia-Martin, R. Kaminski, J.R. Pelaez, J. Ruiz de Elvira
Phys. Rev. Lett. 107 (2011) 072001
[3] J. Beringer et al. (Particle Data Group), Phys. Rev. D86, 010001 (2012).
Author
Robert Kaminski
(Institute of Nuclear Physics PAN)
