Stratified Identity Theory (SIT): A Layered Framework for Particle Identity in Quantum Field Theory

We present Stratified Identity Theory (SIT), a four-layer symbolic framework designed to clarify and formalise the concept of particle identity within Quantum Field Theory (QFT). Rather than treating identity as a single binary property, SIT reformulates the question by asking at which structural layer two excitations or fields share specific, empirically decidable properties. The four layers — the quantum field substrate (L1), fixed species-defining invariants (L2), variable configurational state (L3), and emergent identity (L4) — are interconnected and derived directly from the formalism of QFT. This work does not seek to predict new physical phenomena or modify existing mathematical formulations of particle physics. Instead, it offers a structural and conceptual reorganisation of established QFT concepts, aiming to provide a precise, empirically grounded taxonomy for particle identity. The primary goal of this preprint is to present the foundational core of this symbolic framework, in the hope of inviting community discussion, conceptual feedback, and further collaborative development AI Disclosure: Claude(Anthropic) was utilized solely to refine phrasing, correct grammar, and assist with formatting and structuring author's original thoughts into an academic style. All core concepts, research logic, methodologies, and conclusions are entirely the original work of the author.