  A relativistic diffusion model with cylindrical symmetry, which propagates an
initial state based on quantum chromodynamics in time towards a thermal
equilibrium limit, is derived from nonequilibrium-statistical considerations:
Adapting an existing framework for Markovian stochastic processes representing
relativistic phase-space trajectories, a Fokker-Planck equation is obtained for
the time evolution of particle-number distribution functions with respect to
transverse and longitudinal rapidity. The resulting partially-evolved
distribution functions are transformed to transverse-momentum and
pseudorapidity space, and compared with charged-hadron data from the CERN Large
Hadron Collider (LHC).
