Reappearance of the pairing correlations at finite temperature

Rotational and deformation dependence of isovector and isoscalar pairing correlations at finite temperature are studied in an exactly solvable cranked deformed shell model Hamiltonian. It is shown that isovector pairing correlations, as expected, decrease with increasing deformation and the isoscalar pairing correlations remain constant at temperature, $T=0$. However, it is observed that at finite temperature both isovector and isoscalar pairing correlations are enhanced with increasing deformation. It is also demonstrated that the pair correlations, which are quenched at $T=0$ and high rotational frequency reappear at finite temperature. The changes in the individual multipole pairing fields as a function of rotation and deformation are analyzed in detail.

Figure 1

(Color online) Results of the total isovector (${\Delta }_{t=1}$) and isoscalar (${\Delta }_{t=0}$) pair gaps are plotted as a function of rotational frequency for three different temperatures of $T=0,3$, and 6 MeV. The results for spherical ($\kappa =0$ MeV) and deformed ($\kappa =3$ MeV) nuclei are shown in upper and lower panels, respectively.

Figure 2

(Color online) Results of the total isovector (${\Delta }_{t=1}$) and isoscalar (${\Delta }_{t=0}$) pair gaps are plotted as a function of temperature for three different rotational frequencies of $\hslash \omega =0,2$, and 4 MeV. The upper panel shown the results for $\kappa =0$ and the lower panel depicts the results for $\kappa =3$ MeV.

Figure 3

(Color online) Results of the individual contributing pair fields of $J=0(1),2(3),4(5)$, and 6(7) for the isovector (isoscalar) are plotted as a function of the rotational frequency for temperature, $T=0$.

Figure 4

(Color online) Results of the individual contributing pair fields of $J=0(1),2(3),4(5)$, and 6(7) for the isovector (isoscalar) are plotted as a function of temperature for the rotational frequency of $\hslash \omega =$ 4 MeV.

Figure 5

(Color online) Deformation dependence of the total isovector and isoscalar pair correlations for three temperatures of $T=0,3$, and 6 MeV, shown by solid, long dashed, and dot-dashed lines, respectively.

Figure 6

(Color online) Deformation dependence of the individual contributing pair fields of $J=0(1),2(3),4(5)$, and 6(7) for the total isovector (isoscalar) correlations at temperatures of $T=0,3$, and 6 MeV. $J=0(1)$ is shown by solid line, $J=2(3)$ by dashed line, $J=4(5)$ by long dashed line, and $J=6(7)$ by dot-dashed line.