Collective interaction of QCD strings and early stages of high multiplicity pA collisions

Understand

We study the early stages of "central" pA and peripheral AA collisions.

• Several observables indicate that at a sufficiently large number of participant nucleons the system undergoes a transition into a new "explosive" regime.
• By defining a string-string interaction through the sigma meson exchange and performing molecular dynamics simulation, we argue that one should expect a strong collective implosion of the multi-string "spaghetti" state, creating significant compression of the system in the transverse plane.
• Another consequence is the collectivization of the "sigma clouds" of all strings into a chirally symmetric fireball.