Particles themselves are fundamentally indistinguishable from one another, regardless of whether they are entangled or not. This concept is a fundamental principle in quantum mechanics known as the "indistinguishability of identical particles." According to this principle, particles of the same type cannot be uniquely identified or labeled based on their intrinsic properties alone.
Entanglement, on the other hand, is a quantum phenomenon that can occur between particles. When particles become entangled, their quantum states become correlated in such a way that the state of one particle is dependent on the state of the other, even if they are physically separated. This correlation exists between the entangled particles, but it does not make them individually unique.
In the case of entangled particles, their "flavor" or the specific quantum properties that are entangled, such as spin or polarization, become interconnected. However, this entanglement does not alter the fundamental indistinguishability of the particles themselves. It simply means that the measurement or observation of one particle can provide information about the state of the other particle, without revealing any unique individuality or identity.
So, while entanglement allows for a correlation between particles' quantum states, it does not impart uniqueness or individuality to the particles themselves. The indistinguishability of identical particles remains a fundamental principle of quantum mechanics.