Speaker
Description
The dineutron is a hypothetical bound state of two neutrons in a nuclear medium and a spatially compact pair, different from the one realized by the BCS mechanism[1].The dineutron correlation is expected to appear in various circumstances, such as the surface of weakly bound neutron-rich systems and the inner crust of neutron stars. It has been studied using various approaches, such as the breakup reactions[2,3]. However, previous measurements were insufficient to discuss the magnitude of the dineutron correlation and its density dependence due to the sensitivity of the probe[4].
In the present study, it is found for the first time that the dineutron in the $^{11}$Li nucleus is localized on the surface of the $^{11}$Li nucleus. The use of the quasi-free $(p,pn)$ reaction was essential to extract the radial information of the dineutron and to minimize the effect of the final state interactions[5]. The published results [6] and recent updates will be presented.
References
[1] A. B. Migdal, Soviet J. Nucl. Phys. 16, 238 (1973).
[2] H. Simon et al., Phys. Rev. Lett. 83, 496 (1999).
[3] T. Nakamura et al., Phys. Rev. Lett. 96, 252502 (2006).
[4] Y. Kikuchi et al., Prog. Theor. Exp. Phys. 2016, 103D03 (2016).
[5] Y. Kikuchi et al., Phys. Rev. C 87, 034606 (2013).
[6] Y. Kubota et al., Phys. Rev. Lett. 125 252501 (2020).
