Why the high-lying glueball does not mix with the neighbouring f_0

摘要

Chiral symmetry restoration in high-lying hadron spectra implies that hadrons which belong to different irreducible representations of the parity-chiral group cannot mix. This explains why the f_0(2102 ± 13), which was suggested to be a glueball, and hence must belong to the scalar (0,0) representation of the chiral group, cannot mix with the neighbouring f_0(2040 ± 38), which was interpreted as a nn state, and that belongs to the (1/2,1/2) representation of the chiral group. If confirmed, then we have an access to a true glueball of QCD.