Tobia Toll,A Hotspot Evolution Model for the proton's transverse gluon structure at small x

Tuesday 13 Jun 2023, 11:00 → 13:00 US/Eastern

Observables in incoherent exclusive diffractive DIS at small x are sensitive to fluctuations in the spatial transverse density of the gluon wavefunction in the proton. The Hotspot model has shown success in describing the initial state of the proton in ep, pp and pA collisions. However, as a non-perturbative phenomenological model it is only applicable for small momentum transfers |t|. HERA data has measured the incoherent t-spectrum up to |t|=30 GeV2. We suggest an evolution model of hotspot splittings based on the spatial resolution in the measurement, which can evolve the initial gluon state of the proton in transverse space to all |t|. Our models contain several sources of geometrical fluctuations beyond position, such as hotspot width, number and normalisation at a given resolution. We compare a couple of different implementations of hotspot evolution and investigate what observable effects they have on longitudinal saturation of the gluon density.