  We investigate a chiral d-density wave (CDDW) mean field model Hamiltonian in
the momentum space suitable for the hole-doped cuprates, such as YBCO, in the
pseudo-gap phase to obtain the Fermi surface(FS)topologies, including the
anisotropy parameter(\'Epsilon) and the elastic scattering by disorder
potential (|v0|). For \'Epsilon = 0, the chemical potential {\mu} = - 0.27 eV
for 10% doping level, and |v0| \geq |t| (where |t| = 0.25 eV is the first
neighbor hopping), at zero/non-zero magnetic field (B), the FS on the first
Brillouin zone are found to correspond to Fermi pockets around anti-nodal
regions and barely visible patches around nodal regions. For \'Epsilon \neq 0,
we find Pomeranchuk distortion of FS. We next relate our findings regarding FS
to the magneto-quantum oscillations in the electronic specific heat. Since the
nodal quasi-particle energy values for B = 0 are found to be greater than {\mu}
for |v0| \geq |t|, the origin of the oscillations for non-zero B corresponds to
the Fermi pockets around anti-nodal regions. The oscillations are shown to take
place for 17 T \leq B \leq 53 T and beyond in the weak disorder regime
(|v0|=0.25eV) only.
