1. LPTHE, Department of Physics Faculty of Sciences, Ibn Zohr University PO Box 8106 Agadir Morocco
2. School of Physics University of Chinese Academy of Science Yuquan Road 19A Beijing 100049 China
3. Faculty of Applied Sciences Ibn Zohr University BP 6146 City of Azrou Aït‐Melloul 86150 Morocco
4. Abdus Salam International Centre for Theoretical Physics Strada Costiera, 11 34151 Trieste Italy