Speaker
Petr Bydzovsky
(Nuclear Physics Institute AS CR)
Description
We constructed the multichannel $\pi\pi$ amplitudes in the S- and
P-waves which satisfactorily describe the $\pi\pi$ scattering data [1].
In the construction we have utilized the uniformizing variable and
formulas for analytical continuation of the S-matrix elements to all
sheets of the Riemann surface but we did not fully include the constraint
on the crossing symmetry which is especially important in the S wave.
We modified, therefore, the amplitudes using the once-subtracted dispersion
relations with imposed crossing symmetry (the GKPY equations [2]) to get amplitudes
consistent also with the crossing symmetry [3].
The most pronounced changes of parameters of the amplitudes due to the
modification will be presented and discussed, particularly a position
of the $\sigma$-meson pole (the f$_0$(500) resonance).
1. Yu.S. Surovtsev, P. Byd\v{z}ovsk\'y, R. Kami\'nski, M. Nagy:\\
\hspace*{4mm} Phys. Rev. D 81 (2010) 016001.\\
2. R. Garc\'{\i}a-Mart\'{\i}n, R. Kami\'nski, J.R. Pel\'aez, J. Ruiz de Elvira,
F.J. Yndur\'ain:\\
\hspace*{4mm} Phys. Rev. D 83 (2011) 074004.\\
3. P. Byd\v{z}ovsk\'y, R. Kami\'nski, V. Nazari:\\
\hspace*{4mm} Phys. Rev. D 90 (2014) 116005.
Author
Petr Bydzovsky
(Nuclear Physics Institute AS CR)
Co-authors
Dr
Robert Kaminski
(Institute of Nuclear Physics, Polish Academy of Sciences, Krakow, Poland)
Mr
Vahabeddin Nazari
(Institute of Nuclear Physics PAN, Cracow)
