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 \sim 0.7 \times 10 ^ { -13 } , and another is the high energy positrons observed by the PAMELA satellite experiment .
We construct a supersymmetric flipped-SU ( 5 ) model , SU ( 5 ) \times U ( 1 ) _ { X } with appropriate additional symmetries , [ U ( 1 ) _ { H } ] _ { gauge } \times [ U ( 1 ) _ { R } \times U ( 1 ) _ { \Gamma } ] _ { global } \times Z _ { 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 ( 5 ) singlet leptons , but not allowing anti-proton excess due to the absence of the SU ( 5 ) singlet quarks .
We show the discovery potential of the charged SU ( 5 ) 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 .