  This proposes a new theory of Quantum measurement; a state reduction theory
in which reduction is to the elements of the number operator basis of a system,
triggered by the occurrence of annihilation or creation (or lowering or
raising) operators in the time evolution of a system. It is from these operator
types that the acronym `LARC' is derived. Reduction does not occur immediately
after the trigger event; it occurs at some later time with probability $P_t$
per unit time, where $P_t$ is very small. Localisation of macroscopic objects
occurs in the natural way: photons from an illumination field are reflected off
a body and later absorbed by another body. Each possible absorption of a photon
by a molecule in the second body generates annihilation and raising operators,
which in turn trigger a probability per unit time $P_t$ of a state reduction
into the number operator basis for the photon field and the number operator
basis of the electron orbitals of the molecule. Since all photons in the
illumination field have come from the location of the first body, wherever that
is, a single reduction leads to a reduction of the position state of the first
body relative to the second, with a total probability of $m\tau_L$, where $m$
is the number of photon absorption events. Unusually for a reduction theory,
the larc theory is naturally relativistic.
