Effects of Heavy-Meson Exchange on theD21andF33N−NPartial Waves and the Question of Dibaryon Resonance

The ${}_{}{}^1{}_{}{}^{}D_2^{}{}_{}{}^{}$ and ${}_{}{}^3{}_{}{}^{}F_3^{}{}_{}{}^{}$ $N-N$ amplitudes are studied in a unitary dynamical model. Parameterfree long- and medium-range forces are given by multiple pion exchange, allowing coupling to the $\mathrm{NN}\pi$ channel. Short-range forces are mainly given by $\rho$ and $\omega$ exchange, parametrized to fit known low-energy phase shifts for $J>~2$. Resulting Argand diagrams at medium energies show counter-clockwise loops, but far less dramatic than in the Hoshizaki phase-shift analysis. However, the results are similar to recent Arndt phase shifts.