U.P.B. Sci. Bull., Series A, Vol. 82, Iss. 3, 2020 ISSN 1223-7027 APPEARANCE OF I=1 STAGGERING EFFECTS IN SIGNATURE PARTNERS OF ODD SUPERDEFORMED Tl AND Pb NUCLEI A.M. KHALAF 1 , M.KOTB 2 , Asmaa ABDELSALAM 3 , M.D.OKASHA 4 , Saddon T. AHMAD 5 , Hewa Y. ABDULLAH 6,7* The transition energies of super deformed rotational bands in five pairs of signature partners of 191,193,195 Tl and 193,195 Pb odd-A nuclei are calculated using a proposed energy formula, depending on mixing of rotational and vibrational modes and perturbation term. The level spins of the super deformed band have been estimated with a fit of the Harris expansion to the measured dynamic moment of inertia values as a function of frequency. The model parameters are determined by using a simulated-fitting search program. An excellent agreement between the calculated transition energies and the observed ones supports the model well. Dynamic and kinematic moments of inertia have been calculated, and their dependence on rotational frequency is discussed. The I = 1 staggering splitting in the studied signature partner pairs has been examined through three staggering functions, depending on the dipole and quadrupole -ray transition, linking the two signature partner bands and quadrupole transition within each band. For these signature partner pairs, band head moments of inertia and the intrinsic structure of each pair have been found as almost identical and show a large amplitude staggering pattern. Keywords: Energy Staggering; Signature Partners; Nuclear Superdeformed Bands 1 Prof., Department of physics, Faculty of Science, Al-Azhar University, Cairo, Egypt, e-mail: alikhalaf@azhar.edu.eg 2 Assist. Prof., Department of physic, Faculty of Science, Al-Azhar University, Cairo, Egypt, e-mail: mahmoudkottb@gmail.com Azhar University, - Department of physics, Faculty of Science (Girls branch), Al , PhD, Dept. 3 Cairo, Egypt, e-mail: dr_asmaa_abdelsalam@yahoo.com Azhar University, - of Science (Girls branch), Al , Faculty Department of physics Assist. Prof., 4 Cairo, Egypt, e-mail: mady200315@yahoo.com 5 Assist. Prof., School of Medicine, Koya University, Koya KOY45, Kurdistan Region – F. R. Iraq, e-mail: saddon.taha@koyauniversity.org 6 Assist. Prof., Division of Nuclear Physics, Advanced Institute of Materials Science, Ton Duc Thang University, Ho Chi Minh City, Vietnam, e-mail: hewa.abdullah@tdtu.edu.vn 7 Assist. Prof., Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam, e-mail: (*Corresponding author: hewa.abdullah@tdtu.edu.vn)