We study all available half-favored inclusive single-particle distributions in terms of a quark recombination model. We found that (i) after subtracting out the contributions from resonance decays and diffractive productions, meson-initiated and proton-initiated processes can be described by the same model, and (ii) the shapes of all inclusive distributions, which are produced via VS or VSS recombinations, in the fragmentation region can be described by a generalized Van Hove-Pokorski model with no free parameter.

The nonequilibrium effective action for a charged particle interacting with the quantized electromag- netic fields is derived within the context of the closed-time-path formalism by integrating out field variables in general covariant gauge. The reduced density matrix of the charged particle is then obtained, thus en- abling us to explore quantum decoherence phenomena of the charged particle in terms of the decoherence functional W by an interference experiment under the influence of electromagnetic quantum fluctuations. The issue of gauge invariance of the decoherence functional is discussed.