Is it conceivable at all that the standard model of physics can outperform a quantum computer in any sense?
If quantum computers can simulate in polynomial time the Standard Model, which is a quite complicated quantum field theory, then probably the Standard Model does not provide any extra computational power beyond BQP. Simulating quantum field theories with a quantum computer is not an easy task, but a start has been made by this paper by Jordan, Lee, and Preskill, which shows how to simulate in polynomial time a much simpler quantum field theory than the Standard Model.