Speaker
Description
In an ultra-peripheral collision, where the impact parameter is larger than the sum of the nuclear radii, the nuclei mainly interact electromagnetically. These reactions are mediated by virtual photons. A photon can interact with a gluon in the target nucleus and produce a pair of charm quarks. These charm quarks then fragment and are observed as open charm hadrons ($\rm D^{0}$, $\rm D^{∗} (2010)^{\pm}$ etc.) or vector mesons (J/ψ and ψ(2S)). This process has been used in e-p 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. The cross sections and transverse momentum distributions for D mesons and J/ψ measured in ALICE will be presented. The results will be compared with model calculations.
| Category | Experiment |
|---|---|
| Collaboration (if applicable) | ALICE |
