The π1(1400) meson as a K(K)over-barππ molecule

In this paper the pi(1)(1400) meson with J(PC) = 1(-+) is speculated to be a molecule state which has a similar binding mechanism as the f(1)(1420). With analogy to the f(1)(1420) as a pion orbiting in a P-wave around an S-wave K (K) over bar system, we have a pion orbiting in a P-wave around an S-wave K (K) over bar pi system resonating in the eta(1295). In order to completely derive the dynamics one would have to develop a true four-body scattering mechanism with Born terms connecting two- and three-body isobar states (eta(1295), rho(770), a(0)(980), K-1(1270)). Here we take a short cut and assume a simpler three-body Born term analogous to the final state rescattering mechanism that generated the f(1)(1420). The interactions of the a(0)(980) with the rho(770) through a kaon exchange, which would require a four-body treatment, are replaced by a modification of the P-wave an phase shift. If we allow this modification then binding like the f(1)(1420) can occur. Furthermore when the eta(1295) is formed in rescattering at momentum outside the K (K) over bar pi pi phase space, we assume the eta(1295) will couple to the ground state eta since its quarks and quantum numbers are the same, thus creating eta pi in a P-wave decay.