  Glueball candidates and qqbar mesons have been found to be produced with
different momentum and angular dependences in the central region of pp
collisions. This talk illustrates this phenomenon and explains the phi and t
dependences of mesons with JPC = 0++,0-+, 1++, 2++ and 2-+. For production of
0++ and 2++ mesons the analysis reveals a systematic behaviour in the data that
appears to distinguish between qqbar and non-qqbar or glueball candidates. An
explanation is given for the absence of 0-+ glueball candidates in central
production at present energies and the opportunity for their discovery at RHIC
is noted.
