Speaker
Description
The differential cross section of proton-proton elastic scattering $d \sigma/dt$, as a function of the magnitude of the four-momentum transfer squared $|t|$, evolves in a consistent way with $\sqrt{s}$ at LHC energies, all the curves being translated in the ($|t|$, $d\sigma/dt$) plane for different center-of-mass energies. This means that the cross sections vary according to a scaling law in center-of-mass energy $\sqrt{s}$ 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 $\sqrt{s} = 2.76, 7, 8,$ and $13$ TeV fall in a universal curve when they are mapped to the scaling variables $d\sigma/d|t| (s/\text{TeV}^2)^{-0.305}$ versus $(s/\text{TeV}^2)^{0.065} (|t|/\text{GeV}^2)^{0.72}$. In addition, we explore the implications of this scaling law in the impact parameter picture of the scattering amplitudes.
| In-person participation | No |
|---|
