Upsilon absorption in hadronic matter

The cross sections of Y absorption by pi and rho mesons are evaluated in a meson-exchange model. Including form factors with a cutoff parameter of 1 o r 2 GeV, we find that due to the large threshold of these reactions the the rmal average of their cross sections is only about 0.2 mb at a temperature of 150 MeV. Our results thus suggest that the absorption of directly produc ed Y by hadronic comovers in high energy heavy ion collisions is unimportan t. (C) 2001 Elsevier Science B.V. All rights reserved.