$\Upsilon(1S)$ transverse momentum spectra through dissociation and regeneration in heavy ion collisions

Understand

We calculate the transition between a quarkonium state and an unbound heavy quark-antiquark pair through gluo-dissociation and inelastic parton scattering using a partonic picture that interpolates between the formal limits based on potential nonrelativistic QCD (pNRQCD) at different temperatures.

• While the thermal width increases with momentum and temperature, the quarkonium regeneration is affected by the heavy quark distribution function which depends on the diffusion constant.
• By solving the Boltzmann equation with the dissociation and regeneration terms, we investigate the medium modifications of quarkonium momentum spectra.
• Our numerical results indicate that the $\Upsilon(1S)$ $R_{AA}$ at high transverse momentum are influenced by the regeneration effects depending on the heavy quark diffusion.