[1
]Department of Physics, King Fahd University of Petroleum and Minerals, 31261 Dhahran,
Saudi Arabia
[2
]Saudi Center for Theoretical Physics, P.O. Box 32741, Jeddah 21438, Saudi Arabia
[3
]Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp,
Belgium