Speaker
Haimon Trebien
(Universidade Federal de Santa Catarina)
Description
In this talk, we discuss the exclusive photoproduction of ground and excited states of $\psi(1S,2S)$ and $\Upsilon(1S,2S)$ in ultraperipheral collisions (UPCs). Using the potential approach in order to obtain the vector meson wave function, we find a good agreement of our calculations with data from the LHC and HERA colliders for $J/\psi (1S,2S) $ and $\Upsilon(1S)$ in $\gamma p$ collisions. We extend the calculations, via Glauber--Gribov model, to the nuclear case applying them to $AA$ UPCs . Our results, compared to the LHC data, show the necessity of the inclusion of two main nuclear effects, called gluon shadowing and finite coherence length.
Primary author
Haimon Trebien
(Universidade Federal de Santa Catarina)
