This is a statement of basic textbook physics that is trivially true by definition; quantum field theory explicitly encompasses phenomena such as vacuum states, correlation functions, thermodynamic properties, and phase transitions well beyond scattering amplitudes.
The claim asserts that quantum field theory (QFT) accounts for physical processes other than scattering within its formalism. This is a foundational, trivially true statement about QFT, which deals with bound states, correlation functions, thermodynamics, phase transitions, and vacuum structure. Per the instructions, statements that are trivially true by definition or direct observation are classified as COMMON_KNOWLEDGE, requiring no citation or paper matching.