Polaronic neutron in dilute alpha matter: A $p$-wave Bose polaron
| Autor: | Tajima, Hiroyuki, Moriya, Hajime, Naito, Tomoya, Horiuchi, Wataru, Nakano, Eiji, Iida, Kei |
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| Rok vydání: | 2024 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | We theoretically investigate quasiparticle properties of a neutron immersed in an alpha condensate, which is one of the possible states of dilute symmetric nuclear matter. The resonant $p$-wave neutron-alpha scattering, which plays a crucial role in forming halo nuclei, is considered. This system is similar to a Bose polaron near the $p$-wave Feshbach resonance that can be realized in cold-atomic experiments. Calculating the low-momentum self-energy within the field-theoretical approach, we give an analytical formula for the effective mass of a polaronic neutron as a function of alpha condensation density. Two adjacent neutrons in a medium, each of which behaves like a stable polaron having an enhanced effective mass, can form a bound dineutron, with the help of $^1S_0$ neutron-neutron attraction. This is in contrast to the case of the vacuum, where a dineutron is known to be unbound. Moreover, adding an impurity-like neutron to symmetric nuclear matter can be regarded as a perturbation accompanied by an explicit breaking of Wigner's $ SU \left( 4 \right) $ symmetry. The relationship between the polaron energy and the Wigner term in nuclear mass formulas is discussed in the low-density limit. Our result would be useful for understanding many-body physics in astrophysical environments as well as the formation of multi-nucleon clusters in neutron-halo nuclei. Comment: 13 pages, 6 figures |
| Databáze: | arXiv |
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