Exploring the role of intermediate nucleus spectrum on pairing enhancement in a two-nucleon transfer process

Abstract While forming an ( A +2) nucleus from a nucleus A via a two-neutron transfer reaction, pairing through the continuum of the intermediate ( A +1) nucleus causes the constructive interference of the many possible reaction channels resulting in significant pairing enhancement of cross-sections. This work analyses the situation in more generality, from the point of view of a varying pairing field and different continua leading to the formation of ( A +2) nucleus. I consider $$^6$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mrow/> <mml:mn>6</mml:mn> </mml:mmultiscripts> </mml:math> He and $$^{22}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mrow/> <mml:mn>22</mml:mn> </mml:mmultiscripts> </mml:math> C, described as housing two-neutrons in orbitals of $$^5$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mrow/> <mml:mn>5</mml:mn> </mml:mmultiscripts> </mml:math> He and $$^{21}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mrow/> <mml:mn>21</mml:mn> </mml:mmultiscripts> </mml:math> C, respectively. The different possible situations examined here (including hypothetically bound nuclear systems) manifest that the continuum correlations are extremely crucial to the extension of the pairing enhancement observed in the system.