In this seminar we report on our work on explaining the phenomenon of "stopping" of protons and neutrons, or the puzzle of nuclear stopping power, by a new model of color octet (gluon) exchange in high energy proton-proton and proton-nucleus reactions.
Our results indicate that proton and neutron spectra are governed by color configurations of valence and sea quarks. They also point at the presence of a qualitative difference between single and multiple proton-nucleon collisions, that is, between p-p and p-A reactions.
The encoding of "knowledge" on the number of nucleons which the proton collides with proceeds through the constituent (valence and sea) quark structure of the proton. The increase of the nuclear stopping power in p-A reactions is driven by the emergence of new color configurations with disintegration of the valence "diquark", and the appearance of new "effective diquarks" which contain sea quarks.