The universal size compression effect of nucleon pair in finite nuclei

Abstract

We systematically investigate the size evolution of the di-neutron (2n), di-proton (2p), and deuteron (d) in 6He, 14Be, 17B, 6Be, 17Ne, and 6Li using microscopic calculations. Remarkably, all nucleon pairs exhibit a universal size compression at the nuclear surface, regardless of their species and binding energies. These features correspond to the BCS- and BEC-like nucleon pairs, which recent experimental techniques can further investigate.

Figures (4)

• Figure 1: The RWAs of all types of nucleon pair in $^6$He, $^{14}$Be, $^{17}$B, $^6$Be, $^{17}$Ne, and $^6$Li with different size parameter $s$.
• Figure 2: The RMS distances $d_\text{rms}$ of $2n$ in $^6$He, $^{14}$Be, and $^{17}$B along with the radius $a$, respectively.
• Figure 3: The RMS distance $d_\text{rms}$ of $2p$ in $^{6}$Be and $^{17}$Ne along with the radius $a$.
• Figure 4: The RMS distance $d_\text{rms}$ of $d$ in $^6$Li along with the radius $a$.