Consider one particle traveling at a relativistic velocity in 3-space. Then the configuration space of the system consisting of that one particle would have 3 degrees of freedom – 1 particle times 3 dimensions. Because of its high energy, the particle decays into, say, 2 particles. Now the configuration space of the system has 6 degrees of freedom. Is the above correct? But, the 2 particles are now entangled in position (as well as momentum). So does the configuration space truly have 6 degrees of freedom, or something less than that due to position correlation between the 2 particles? Thanks in advance.