Seminarium "Teoria cząstek elementarnych i kosmologia"

I will discuss quantum entanglement in high-energy scattering of two particles characterized by an internal quantum number acting like a qubit. Working with a perturbative S-matrix, I will build the reduced density matrix of the final scattered state by tracing out the momentum degrees of freedom. In this construction, unitarity is guaranteed order by order by the optical theorem. I will present a novel analytical formula for the concurrence (qubit entanglement) of a mixed final state and show that, given an initial product state, it depends at the leading order on the real part of the inelastic forward amplitude. I will also address a recent proposal stating that some symmetries of the Lagrangian may emerge from a principle of entanglement minimization. I will show that for “flavored” scalar scattering this does not appear to be the case.

SLIDES