Spin Analysis ofpπ+π−Enhancements in theppπ+π−Final State Produced inppInteractions at 22 GeV/c

Abstract

We have investigated decay angular distributions and other characteristics associated with enhancements near 1450 and 1700 MeV in the $p{\pi }^{+}{\pi }^{-}$ mass distribution for the $\mathrm{pp}{\pi }^{+}{\pi }^{-}$ final state produced in $\mathrm{pp}$ interactions at 22 GeV/c. Our results are consistent with a spin assignment of ½ for the 1450-MeV effect if the ${\Delta }^{++}{\pi }^{-}$ branching of this effect is assumed to be small. We associated this effect with the $P_{11}\mathrm{}\left(1470\right)\mathrm{}$ state inferred from phase-shift analyses. In the case of the 1700-MeV feature, we favor strong contributions from a $J={\frac{5}{2}}^{+}$ state which can be reasonably associated with the $F_{15}\mathrm{}\left(1690\right)\mathrm{}$ state reported in the phase-shift work.