Modification of 𝜒𝑐⁢1⁡(3872) and 𝜓⁡(2⁢𝑆) Production in 𝑝⁢Pb Collisions at √𝑠NN=8.16  TeV

The LHCb Collaboration measures production of the exotic hadron χc1(3872) in proton-nucleus collisions for the first time. Comparison with the charmonium state ψ(2S) suggests that the exotic χc1(3872) experiences different dynamics in the nuclear medium than conventional hadrons, and comparison with data from proton-proton collisions indicates that the presence of the nucleus may modify χc1(3872) production rates. This is the first measurement of the nuclear modification factor of an exotic hadron.