Prof. Georg Wolschin (University Heidelberg)

Bottomia physics at RHIC and LHC energies

The suppression of Y mesons in the hot quark-gluon medium (QGP) versus reduced feed-down is investigated at energies reached at the Relativistic Heavy Ion Collider RHIC and the Large Hadron Collider LHC. Our centrality- and p_T-dependent model encompasses screening, collisional damping and gluodissociation in the QGP. For the Y(1S) ground state it is in agreement with both STAR and CMS data provided the relativistic Doppler effect and the reduced feed-down from higher states are properly considered. At both energies, most of the Y(1S) suppression is found to be due to reduced feed-down, whereas most of the Y(2S) suppression is caused by hot-medium effects. The importance of the latter increases with energy. The p_T-dependence is flat due to the relativistic Doppler effect and reduced feed-down. Results for PbPb at 5.02 TeV are predicted and compared with recent LHC run 2 preliminary data.