$\Upsilon$ absorption cross sections by nucleons

Abstract

The cross sections of $\Upsilon $\ absorption by nucleons are calculated in meson-baryon exchange model using an effective hadronic Lagrangian. Calculated cross sections are found to peak near threshold followed by an increase which tends to settle at large center of mass energy. Peak values are found in range about 1.8 to 4 mb when cutoff parameter of monopole form factor is varied from 1.2 to 1.8 GeV. The results disagree with pQCD calculations but are consistent with the effective value of the absorption cross section extracted from p-A scattering data in E772 experiment at $\sqrt{s_{NN}}=39$ GeV. We use this data value to find a best fit of the cutoff parameter which enables us provide definite predictions for the values of $\Upsilon $ absorption cross sections by nucleons for upcoming p-A scattering experiments at RHIC and LHC energies for zero rapidity $b\bar{b}$ states. The results could be useful in studying the effect of $\Upsilon $ absorption by nucleons at its production stage in relativistic heavy-ion collision experiments. We also find that thermal averaged values of total absorption cross sections are small enough to rule out the effect of absorption of $\Upsilon $ by the comovers in the hadronic matter.