Quarkonium suppression with the jumptime method

The quark-gluon plasma is a new state of matter that can be formed by colliding heavy ions at ultrarelativistic velocities. From all the particles formed in these collisions, heavy quarkonium is one of the most promosing probes to obtain information about this new state of matter. One of the most succesful approaches to the study of the evolution of quarkonium in a medium is to model it as a Markovian open quantum system. Recently, it has been found using this approach that regeneration is crucial to reproduce experimental data on quarkonium excited states. However, it has been observed that after including regeneration the number of detected Upsilon(2S) states over Upsilon (1S) increases but the ratio of Upsilon(3S) over Upsilon(2S) decreases. This result is unintuitive because s-wave quarkonium states are ordered in size and, therefore, we expect larger states to be more suppressed by the medium. We propose to find the reason of this behaviour by studying the evolution of quarkonium with a recently proposed numerical method, the Jumptime unravelling. References:N. Brambilla, M.A. Escobedo, J. Soto and A. Vairo, Quarkonium suppression in heavy-ion collisions: an open quantum system approach, Phys. Rev. D \textbf{96} (2017) no.3, 034021 [arXiv:1612.07248 [hep-ph]].