Characterisation of the dip-bump structure observed in proton–proton elastic scattering at s = 8 TeV

Abstract

The TOTEM collaboration at the CERN LHC has measured the differential cross-section of elastic proton–proton scattering at $\sqrt{s}=8\mathrm{TeV}$ in the squared four-momentum transfer range $0.2{\mathrm{GeV}}^2<|t|<1.9{\mathrm{GeV}}^2$. This interval includes the structure with a diffractive minimum (“dip”) and a secondary maximum (“bump”) that has also been observed at all other LHC energies, where measurements were made. A detailed characterisation of this structure for $\sqrt{s}=8\mathrm{TeV}$ yields the positions, ${|t|}_{\mathrm{dip}}=(0.521\pm 0.007){\mathrm{GeV}}^2$ and ${|t|}_{\mathrm{bump}}=(0.695\pm 0.026){\mathrm{GeV}}^2$, as well as the cross-section values, ${\left(\mathrm{d}\sigma /\mathrm{d}t\right|}_{\mathrm{dip}}=(15.1\pm 2.5)\mu \mathrm{b}/{\mathrm{GeV}}^2$ and ${\left(\mathrm{d}\sigma /\mathrm{d}t\right|}_{\mathrm{bump}}=(29.7\pm 1.8)\mu \mathrm{b}/{\mathrm{GeV}}^2$, for the dip and the bump, respectively.