Application of dispersion relations to ηπ elastic scattering

Abstract

The existence of exotic mesons, particularly hybrid mesons, remains a subject of investigation. Among these, the meson π1 with JPC = 1 −+ is anticipated to be the lightest. In this study, we examine the reaction η( ′ )π → η( ′ )π as π1 couples to the involved particles. By employing dispersion relations for various channels of this reaction, incorporating Regge forms, and conducting a partial wave expansion in both the forward and backward directions of the outgoing particles, we estimate the P-wave contribution associated with the purported π1 meson.