The proton-proton elastic differential cross section ${\rm d}\sigma/{\rm d}t$ has been measured by the TOTEM experiment at $\sqrt{s}=2.76$~TeV energy with $\beta^{*}=11$~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 $0.36$~GeV$^{2}$ to $0.74$~GeV$^{2}$. The differential cross-section can be described with an exponential
in the $|t|$-range between $0.36$~GeV$^{2}$ and $0.54$~GeV$^{2}$, followed by a diffractive minimum (dip) at $|t_{\rm dip}|=(0.61\pm0.03)$~GeV$^{2}$ and a subsequent maximum (bump). The ratio of the ${\rm d}\sigma/{\rm d}t$ at the bump
and at the dip is $1.7\pm0.2$. When compared to the proton-antiproton measurement of the D0 experiment at $\sqrt s = 1.96$~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 elastic scattering.