Studies of exotic hadrons such as the χc1​(3872) state provide
crucial insights into the fundamental force governing the strong interaction
dynamics, with an emerging new frontier to investigate their production in high
energy collisions where a partonic medium is present. Latest experimental
measurements from the Large Hadron Collider show an intriguing evolution
pattern of the χc1​(3872)-to-ψ(2S) yield ratio from proton-proton
collisions with increasing multiplicities toward proton-lead and lead-lead
collisions. Here we propose a novel mechanism of medium-assisted enhancement
for the χc1​(3872) production, which competes with the more
conventional absorption-induced suppression and results in a non-monotonic
trend from small to large colliding systems. Realistic simulations from this
model offer the first quantitative description of all available data.
Predictions are made for the centrality dependence of this observable in PbPb
collisions as well as for its system size dependence from OO and ArAr to XeXe
and PbPb collisions. In both cases, a non-monotonic behavior emerges as the
imprint of the competition between enhancement and suppression and can be
readily tested by future data.Comment: 7 pages, 4 figure