Revealing nucleon and nucleus flickering in pA collisions at the LHC

Understand

We analyze $pA$ interactions at ultra-high energies within the semiclassical approximation for high energy processes accounting for the diffractive processes and a rapid increase with the incident energy of the coherence length.

• The fluctuations of the strength of interaction expected in QCD and momentum conservation are taken into account also.
• We evaluate the number of wounded nucleons in soft and hard processes, the multiplicity of jets in the proton fragmentation region as a function of the variance of the distribution over the interaction strengths directly measured in forward diffractive $pN$ scattering for RHIC and LHC energies.
• We argue that these results could be used to test whether parton configurations containing a parton carrying the $x\ge 0.5$ fraction of the projectile momentum interact significantly weaker than on average.