  Motivated by a special consideration in quantum measurement, we present a new
improved energy-momentum tensor. The new tensor differs from the traditional
canonical and symmetric ones, and can be derived as Nother current from a
Lagrangian with second derivative. We also attempt to construct a gravitational
coupling in such a way that the new energy-momentum tensor becomes the source
of the gravitational field. The theory we obtain is of an Einstein-Cartan type,
but derived from a minimal coupling of a Lagrangian with second-derivative, and
leads to additional interaction between torsion and matter, including the
scalar field. For the scalar field, the theory can also be derived in the
Riemann space-time by a non-minimal coupling. Our study gives hint on more
general tests of general relativistic effects.
