Contribution parallel talk
Partial wave analysis of $\pi \pi$ scattering below 2 GeV
Abstract content
In a unitary multi-channel approach, precise determination of $\pi \pi$ scattering amplitudes for $D$ and $F$ waves has been presented. These scattering amplitudes are in the $I^{G}J^{PC}$ = $0^{+}2^{++}$ sector on the processes of $\pi\pi$ $\rightarrow$ $\pi\pi$, $4\pi$, $K \bar K$ and $\eta\eta$, likewise in the $I^{G}J^{PC}$ = $1^{+}3^{--}$ sector on the processes of $\pi\pi$ $\rightarrow$ $\pi\pi$, $4\pi$, $\omega\pi$ and $K \bar K$ for $D$ and $F$ waves respectively. The amplitudes were refined and re-fitted to the dispersion relations up to 1.1 GeV, and to the experimental data in the effective two pion mass from the threshold to 2.7 GeV and 1.9 GeV for $D$ and $F$ waves, respectively. Old parameterizations did not satisfy the crossing symmetry condition and did not describe the $\pi\pi$ threshold region. Moreover, a satisfactory justification regarding the controversies in the states of $f_2$ and $\rho_3$ mesons about their masses and number of states that are taken into account has been discussed and finalized.