  Recently, there are two hints arising from physics beyond the standard model.
One is a possible energy loss mechanism due to emission of very weakly
interacting light particles from white dwarf stars, with a coupling strength ~
0.7x10^{-13}, and another is the high energy positrons observed by the PAMELA
satellite experiment. We construct a supersymmetric flipped-SU(5) model,
SU(5)xU(1)_X with appropriate additional symmetries,
[U(1)_H]_{gauge}x[U(1)_RxU(1)_\Gamma]_{global}xZ_2, such that these are
explained by a very light electrophilic axion of mass 0.5 meV from the
spontaneously broken U(1)_\Gamma and two component cold dark matters from Z_2
parity. We show that in the flipped-SU(5) there exists a basic mechanism for
allowing excess positrons through the charged SU(2) singlet leptons, but not
allowing anti-proton excess due to the absence of the SU(2) singlet quarks. We
show the discovery potential of the charged SU(2) singlet E at the LHC
experiments by observing the electron and positron spectrum. With these
symmetries, we also comment on the mass hierarchy between the top and bottom
quarks.
