If the $$\widehat\rho $$ (1405) is the exotic 1−(1− +) hybrid, then where are the non-exotic ones?(1405) is the exotic 1−(1− +) hybrid, then where are the non-exotic ones?

Abstract

The decays of hybrid\(q\bar qg\) mesons are considered with the assumption that the lowest hybrids are those containing 1+ constituent gluon. The selection rules for the hybrid decays into two mesons are obtained and compared with the experimentally observed decay pattern for the mesons in the mass region 1–2GeV. The estimate of partial widths for the 1− + hybrid shows that the hybrid assignment is compatible with the properties of exotic\(\widehat\rho \)(1405) state. Setting the absolute scale of mass for hybrids in this way one may look for hybrids with non-exotic quantum numbers, and it appears that large admixture of 0− + and 2− + hybrids may be allowed for the π(1300) and π2(1670) correspondingly. Similarly, the controversial data on e+e− annihilation into pions in the energy region around 1.5 GeV may be explained in terms of mixing of 23S1 quark-antiquark states to 1−− isovector and isoscalar hybrids.