  We searched for periodic and quasiperiodic signal in the prompt emission of a
sample of 44 bright short gamma-ray bursts detected with Fermi/GBM, Swift/BAT,
and CGRO/BATSE. The aim was to look for the observational signature of
quasiperiodic jet precession which is expected from black hole-neutron star
mergers, but not from double neutron star systems. Thus, this kind of search
holds the key to identify the progenitor systems of short GRBs and, in the wait
for gravitational wave detection, represents the only direct way to constrain
the progenitors. We tailored our search to the nature of the expected signal by
properly stretching the observed light curves by an increasing factor with
time, after calibrating the technique on synthetic curves. In none of the GRBs
of our sample we found evidence for periodic or quasiperiodic signals. In
particular, for the 7 unambiguously short GRBs with best S/N we obtained
significant upper limits to the amplitude of the possible oscillations. This
result suggests that BH-NS systems do not dominate the population of short GRB
progenitors as described by the kinematic model of Stone, Loeb, & Berger
(2013).
