$\Upsilon$ suppression in a hadron gas

In this work we study the interactions of bottom mesons which lead to $\Upsilon$ production and absorption in hot hadronic matter. We use effective Lagrangians to calculate the $\Upsilon$ production cross section in processes such as $\bar{B}^{(*)} + B^{(*)} \to \Upsilon + (\pi, \rho)$ and also the $\Upsilon$ absorption cross section in the corresponding inverse processes. We update and extend previous calculations by Lin and Ko, introducing anomalous interactions. The obtained cross sections are used as input to solve the rate equation which allows us to follow the time evolution of the $\Upsilon$ multiplicity. In contrast to previous conjectures, our results suggest that the interactions in the hadron gas phase strongly reduce the $\Upsilon$ abundance.