Study of the nature of $ι/η(1440)$ in the chiral perturbation theory approach
Abstract
Description
The nature of $ι/η(1440)$ is analysed in the framework of the hypothesis that it represents a single pseudoscalar resonance. Assuming that it arises due to the mixing between the glueball and the $q\bar q$ nearby states ($η$, $η'$, and their radial excitations) two upper estimates are obtained for the partial width $Γ(ι/η(1440) \to K^* K)$ --- one for the case when $ι/η(1440)$ is mainly a glueball and another one when it is mainly a radial excitation of the $s\bar s$ state. Both estimates are obtained in the chiral perturbation theory approach taking into account the available data on the vector mesons and the pseudoscalar state K(1460), which is interpreted as a radial excitation of the $K$ meson. The same partial width is independently estimated on the basis of the combined OBELIX and Crystal Barrel data on the production of $ι/η(1440)$ in $p\bar p$ annihilation. Comparing the results we show that the glueball content of $ι/η(1440)$ is suppressed while its $s\bar s$ radial-excitation interpretation is favoured by the data.
18 pages, LaTeX, no figures. Minor corrections (mainly linguistic and spelling ones)
18 pages, LaTeX, no figures. Minor corrections (mainly linguistic and spelling ones)