  If an Unruh-DeWitt detector operates for an infinite proper time along the
trajectory of a uniformly accelerated observer in Fock space then induced
transition rate of the detector is proportional to Planck distribution. For a
realistic detector which operates only for a finite period, the instantaneous
transition rate contains both transient and non-transient terms. In particular,
the non-transient term contains a residue evaluated at the pole of the
two-point function. We show here by considering a massless scalar field that
unlike in Fock quantization, the short-distance two-point function contains no
pole in polymer quantization, the quantization techniques used in loop quantum
gravity. Consequently, corresponding transition rate of the Unruh-DeWitt
detector contains only transient terms. Thus, the result presented here
provides an alternative evidence for absence of Unruh effect in polymer
quantization which was shown earlier by the authors using methods of Bogoliubov
transformation and Kubo-Martin-Schwinger condition.
