Speaker
Description
We explore the consequences of gluonic hot spots in the proton for coherent and incoherent exclusive vector meson production cross sections. For the proton we use the Color Glass Condensate framework in the dilute limit with Gaussian hot spots of fluctuating color charges, which we are able to average over analytically. The cross sections are computed using the lowest order dipole model and the vector meson wave function is are taken to be non-relativistic. We find that the coherent cross section is sensitive to both the size of the target and the structure of the probe. The incoherent cross section is dominated by color fluctuations at small transverse momentum transfer ($t$), by proton and hot spot sizes as well as the structure of the probe at medium $t$ and again color fluctuations at large $t$. While the $t$-dependence of the cross section is well reproduced by our model, the relative normalization between the coherent and the incoherent cross sections points to the need for additional fluctuations in the proton.
