New probes of nuclear gluon dynamics through photoproduction of charm in inelastic ultra-peripheral Pbx2014Pb collisions with ALICE

In an ultra-peripheral collision, a photon can interact with a gluon in the target nucleus and produce a pair of charm quarks, while the target nucleus breaks up (inelastic scattering). These charm quarks then fragment and are observed as open charm hadrons or vector mesons. This process has been used in ex2014p collisions to set stringent limits on the proton gluon distribution at low-x. The current measurements can provide similar constraints on the much less known nuclear gluon distributions. ALICE has measured the transverse momentum distribution of inelastically photoproduced D⁰ at midrapidity, in Pbx2014Pb collisions at sNN=5. 36 TeV. The distribution is measured down to pT=0 for the first time. The results are compared to model calculations.