Study of piN->pipiN processes on polarized targets: Quantum environment and its dephasing interaction with particle scattering

Unitary evolution law describes isolated particle scattering processes in an empty Minkowski spacetime. We put forward a hypothesis that the physical Universe includes a quantum environment that interacts with particle scattering processes. While the scattering process is governed by the S-matrix the interaction evolves the produced state rho_f(S) to observed state rho_f(O). To be consistent with the Standard Model this new interaction must be a pure dephasing interaction governed by a non-unitary evolution law modifying the phases of the amplitudes. We present the first test of the unitary evolution law in particle scattering. The unitary evolution law evolves pure initial states into pure final states in exclusive processes. This fact leads to 9 independent constraints on 16 components of angular intensities in piN->pipiN processes. When expressed in terms of P-parity conserving transversity amplitudes all 9 constraints are identities provided a single constrain on the transversity amplitudes holds true. The constraint implies that the relative phases between transverity amplitudes of the same naturality and transversity must be 0 or +/- pi. All previous amplitude analyses of the piN->pipiN processes found non-unitary relative phases in an apparent violation of the unitary evolution law. The contrast between the predicted and the observed relative phases presents an unambigous evidence for the existence of the quantum environment and its pure dephasing interaction with particle scattering processes.