Spin-parity analysis of the K∗(890)π system in the Q-region

Abstract We have used a multipole moments analysis to determine the spin-parity of the K ∗ π system in the Q-region ( 1.0 GeV K ∗ π) GeV ) , using events from the reaction K + p → K + p π + π − at 5.5 GeV/ c . We find J P = 1 + over the whole of this mass range. Observed effects which could be due to the presence of states of higher spin in the Q-enhancement (or to the presence of a Kϱ decay mode of the Q) can be satisfactorily explained as arising from the cuts made in the data for the K ∗ π decay of a pure J P = 1 + state.