The TOTEM (TOTal cross section, Elastic scattering and diffraction
dissociation Measurement at the LHC) experiment, located at the
interaction point 5 of the LHC, has measured the total, elastic and
inelastic proton-proton cross-sections, using a luminosity independent
method, based on the optical theorem, in a center-of-mass energy range
from 2.76 to 13 TeV. The elastic scattering was investigated in a wide
range of the squared four-momentum transfer $|t|$ allowing study
of the Coulomb-nuclear interference region down to $|t| \sim 8\times
10^{-4}$ GeV$^{2}$. This made possible the first measurement of the $\rho$
parameter at $\sqrt{s} = 13$ TeV, $\rho$ being the ratio between the real
and the imaginary part of the nuclear elastic scattering amplitude at
$t = 0$. This measurement, combined with the total cross-section
results, led to the exclusion of all the models classified and
published by the COMPETE Collaboration. The results obtained by TOTEM
are indeed compatible with predictions of a colourless 3-gluon bound
state exchange in the t-channel of proton-proton elastic scattering,
as postulated by alternative theoretical models both in the Regge-like
framework and in the modern QCD framework.
In this contribution the TOTEM experiment detectors and results will
be described, along with the actual experiment status, the future
physics program for the LHC Run~3.