Central pi(+)pi(-) events produced in pp interactions are studied in t
erms of correlations between the outgoing protons. It is observed ther
e is more rho(0)(770) and f(2)(1270) production in reactions where the
outgoing protons are on opposite sides of the beam. This effect is no
t attributable to the trigger or the experimental acceptance, and sugg
ests that the vertices do not factorise.