  For the energy of 14 TeV, to be reached at the Large Hadron Collider (LHC),
we have had for some time accurate predictions for both the real and imaginary
parts of the forward proton-proton elastic scattering amplitude. LHC is now
scheduled to start operating in two years, and it is timely to discuss some of
the important consequences of the measurements of both the total cross-section
and the ratio of the real to the imaginary part. We stress the importance of
measuring the real part of the proton-proton forward scattering amplitude at
LHC, because a deviation from existing theoretical predictions could be a
strong sign for new physics.
