  New experimental data about proton-proton collisions obtained atthe LHC allow
to widen strongly the energy interval where one gets some knowledge about the
structure of their interaction region. Using the unitarity relation in
combination with experimental data about the elastic scattering in the
diffraction cone, it is shown how the shape and the darkness of the interaction
region of colliding protons change with increase of their energies. In
particular, the collisions become fully absorptive at small impact parameters
at LHC energies that results in some special features of inelastic processes as
well. Possible evolution of the shape from the dark core at the LHC to the
fully transparent one is discussed that implies the terminology of the black
disk would be replaced by the black torus. The parameter which determines the
opacity of central collisions also plays a crucial role in the behavior of the
differential cross section of elastic scattering outside the diffraction cone
where the predictions of all phenomenological models failed at LHC energies.
The role of the ratio of real to imaginary part of the elastic scattering
amplitude at non-forward scattering becomes decisive there as seen from the
unitarity condition. The obtained results allow to estimate this ratio outside
the diffraction cone for the first time by comparison with experiment at LHC
energies which happens to be drastically different from its values measured at
forward scattering. Moreover, the behaviors of the real and imaginary parts
separately differ in different phenomeno- logical models and in the approach
based on the unitarity condition. This problem is still waiting for its
resolution. All the conclusions are only obtained in the framework of the
indubitable unitarity condition using experimental data about the elastic
scattering.
