Speaker
Description
he differential cross section of proton-proton elastic scattering 𝑑𝜎/𝑑𝑡, as a function of the magnitude of the four-momentum transfer squared |𝑡|, evolves in a consistent way with 𝑠√ at LHC energies, all the curves being translated in the (|𝑡|, 𝑑𝜎/𝑑𝑡) plane for different center-of-mass energies. This means that the cross sections vary according to a scaling law in center-of-mass energy 𝑠√ and on |𝑡|.
These features suggest there are hidden universal properties of elastic scattering. Based on these empirical observations, and taking inspiration from saturation models, we propose a simple scaling law for proton-proton elastic scattering. The differential cross sections measured by TOTEM at 𝑠√=2.76,7,8, and 13 TeV fall in a universal curve when they are mapped to the scaling variables 𝑑𝜎/𝑑|𝑡|(𝑠/TeV2)−0.305 versus (𝑠/TeV2)0.065(|𝑡|/GeV2)0.72. In addition, we explore the implications of this scaling law in the impact parameter picture of the scattering amplitudes.
