  The ground-state spin and parity of a formed daughter in the radioactive
Alpha-emitter is expected to influence the preformation probability of the
Alpha and daughter clusters inside it. We investigate the Alpha and daughter
preformation probability inside odd-A and doubly-odd radioactive nuclei when
the daughter and parent are of different spin and/or parity. We consider only
the ground-state to ground-state unfavored decays. This is to extract precise
information about the effect of the difference in the ground states spin-parity
of the involved nuclei far away any influences from the excitation energy if
the decays are coming from isomeric states. The calculations are done for 161
Alpha-emitters, with Z=65-112 and N=84-173, in the framework of the extended
cluster model, with WKB penetrability and assault frequency. We used a
Hamiltonian energy density scheme based on Skyrme-SLy4 interaction to compute
the interaction potential. The Alpha plus cluster preformation probability is
extracted from the calculated decay width and the experimental half-life time.
We discussed in detailed steps the effect of angular momentum of the emitted
Alpha-particle on the various physical quantities involved in the unfavored
decay process and how it is finally increases the half-life time. We found that
if the ground states spin and/or parity of parent and daughter nuclei are
different, then the preformation probability of the Alpha-cluster inside parent
is less than it would be if they have similar spin-parity. We modified the
formula that gives the Alpha preformation probability in terms of the numbers
of protons and neutrons outside the shell closures of parent, to account for
this hindrance in the preformation probability for the unfavored decays between
ground states.
