| Abstract: |
In quantum information theory, the evolution of an open quantum system -- a unitary evolution with the environment followed by a measurement -- is described by a Quantum Channel or, more generally, a Quantum Instrument. In this talk, I will formulate spin and flavour measurements in collider experiments as a Quantum Instrument. We demonstrate that the Choi matrix, which completely determines input-output transitions, can be both theoretically computed from a given theoretical model (e.g. the Standard Model) and experimentally reconstructed from a set of final state measurements (quantum state tomography) using varied input states. The reconstruction of the Choi matrix, known as quantum process tomography, offers a powerful new approach for probing potential extensions of the Standard Model within the QFT framework and also provides a fundamental test of Quantum Mechanics itself. As an example, I will outline a quantum process tomography approach applied to the e+ e- -> t tbar process at a polarized lepton collider. |
