Speaker
Anatoly Gridnev
(NRC KI - PNPI)
Description
Experimental data on $pi N $ scattering in the elastic energy region $W leq 1.45 GeV $ are analyzed within the $K$-matrix approach with effective Lagrangians. The charge splitting in $delta^{++}_{33}$ and $delta^{0}_{33}$ phases obtained in the phase shift analysis is studied . It is shown that the change in the sign in the energy dependence of the phase difference can be obtained with different formfactors of the $Delta^{++}$ and $Delta^{0}$ only . This means that $Delta^{++}$ and $Delta^{0}$ has a different size in $pi N $ interaction.The underlying nature of the observed phenomena is discussed. $pi NDelta^{++} $ and $pi NDelta^{0} $interactions has a different range.
