In quantum theory, and especially quantum field theory, the nature of quantum states is transformed if the particles are identical. In fact, the impact of particles (or better quanta) being identical is more profound in quantum theory than in classical mechanics. Their identity has direct experimental consequences over and above those related to the occupation of states. Over the next couple of chapters, we will explore the quantum theory of identical particles to draw out the impact on the entropy of a collection of such particles .
Scattering is an important phenomenon of microscopic particle's interaction. The identical particles are the particles with inherent identical character in mass,electric charge,spin,etc. They show some special characteristic in their scattering. In this paper,the identical particles' scattering has been analysed from the symmetry of wave function, scattering cross - section and probabiliy. A comparison is made betwwen scattering of the identical particles and that of the non - identical particles.
The mathematical rules used to handle systems of identical quantum particles bring into question whether the elementary constituents of matter, such as electrons, have the fundamental characteristics of persistence and reidentifiability that are usually attributed to classical particles. However, despite considerable philosophical debate, the metaphysical profile of these entities remains elusive.
Previous debates have taken the mathematical rules, and the language in which these are usually couched, as a starting point. Here, we argue that this methodology is inherently limited, and develop a new conception of identical particles based on a recent mathematical reconstruction of these rules. Using this reconstruction, we demonstrate that the special behaviour of identical particles originates in the confluence of identicality and the active nature of the quantum measurements. We propose that identical particles are appropriately viewed as potential parts of a whole, and show how this leads to striking consequences such as restricted transtemporal identity.
If, in a system of identical particles, the one particle state is defined by the partial trace to one of the component spaces of the total Hilbert space, then all one particle states are identical. The particles are indistinguishable. This is often thought to be a typical quantum mechanical phenomenon. I will show however that an analogous procedure to define particle states exists in classical mechanics, which results in classical indistinguishable identical particles. From this analogy it follows that the indistinguishability of identical particles depends on how we define particle states. It is not an inevitable result of the symmetry postulate. Indeed, if particles are defined by partial traces, consistent use of the symmetry postulate leads to the conclusion that all identical particles in the universe are indistinguishable, so that particles can never be pointed at, not even in the classical limit. This does not correspond to the way the term particle is actually used in practice. I will argue that a particle should be defined in such a way that in the classical limit the quantum particle state becomes the state of a classical particle. This will lead us to a definition of particles which is in line with the way the term particle is actually used by physicists.