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 $|t_{rm dip}| = 0.61 pm 0.03$ 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 $1.7pm 0.2$. When compared to the $rm pbar{p}$ 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 a colourless 3-gluon bound state exchange in the $t$-channel of the proton-proton elastic scattering.
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