Elastic differential cross-section dσ /dt at √(s)=2.76 TeV and implications on the existence of a colourless C-odd three-gluon compound state

The proton–proton elastic differential cross section dσ /dt has been measured by the TOTEM experiment at √(s)=2.76 TeV energy with β ^*=11 m beam optics. The Roman Pots were inserted to 13 times the transverse beam size from the beam, which allowed to measure the differential cross-section of elastic scattering in a range of the squared four-momentum transfer (| t |) from 0.36 to 0.74 GeV^2 . The differential cross-section can be described with an exponential in the | t |-range between 0.36 and 0.54 GeV^2 , followed by a diffractive minimum (dip) at |t_dip|=(0.61± 0.03) GeV^2 and a subsequent maximum (bump). The ratio of the dσ /dt at the bump and at the dip is 1.7± 0.2 . When compared to the proton–antiproton measurement of the D0 experiment at √(s) = 1.96 TeV , a significant difference can be observed. Under the condition that the effects due to the energy difference between TOTEM and D0 can be neglected, the result provides evidence for the exchange of a colourless C-odd three-gluon compound state in the t -channel of the proton–proton and proton–antiproton elastic scattering.