Study of the nature of
chiral perturbation theory approach
M. L. Nekrasov
Institute for High Energy Physics, 142284 Protvino, Russia (e-mail: firstname.lastname@example.org)
Received: 25 November 1997 / Revised version: 6 January 1998 / Published online: 24 April 1998
The nature of 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 nearby states (, , and their radial excitations) two upper estimates are obtained for the partial width -- one for the case when is mainly a glueball and another one when it is mainly a radial excitation of the 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 in annihilation. Comparing the results we show that the glueball content of is suppressed while its radial-excitation interpretation is favoured by the data.