2019 January 11
The suppression of Y-mesons in the hot quark-gluon plasma (QGP) versus reduced feed-
down is investigated in heavy-ion collisions at energies reached at the Large Hadron Collider
(LHC). Our model encompasses screening, collisional damping and gluodissociation in the
QGP. It provides p_T- and centrality-dependent results for the six states involved.
Most of the Y(1S)-suppression is found to be due to reduced feed-down, whereas the
Y(2S)-suppression is mainly caused by hot-medium effects in the collectively expanding QGP.
The previously predicted Y(1S)-suppression in PbPb collisions at sqrt(s_NN) = 5.02 TeV agrees
with recent CMS data, whereas the data for Y(2S) are more strongly suppressed compared to
calculated results in peripheral collisions. Predictions for fixed-target experiments with a
2.76 TeV Pb-beam are shown.