https://doi.org/10.1140/epja/i2017-12313-7
Regular Article - Theoretical Physics
Dipole-dipole dispersion interactions between neutrons
1
ITAMP, Harvard-Smithsonian Center for Astrophysics, MS 14, 60 Garden St., 02138, Cambridge, MA, USA
2
Instituto de Física, Universidade de São Paulo, R. do Matão 1371, 05508-090, São Paulo, S.P., Brazil
3
Instituto de Estudos Avançados, Universidade de São Paulo, C.P. 72012, 05508-970, São Paulo, S.P., Brazil
4
Departamento de Física, Instituto Tecnológico de Aeronáutica, CTA, São José dos Campos, S.P., Brazil
* e-mail: hussein@if.usp.br
Received:
19
December
2016
Accepted:
8
May
2017
Published online:
15
June
2017
We investigate the long-range interactions between two neutrons utilizing recent data on the neutron static and dynamic electric and magnetic dipole polarizabilities. The resulting long-range potentials are used to make quantitative comparisons between the collisions of a neutron with a neutron and a neutron with a proton. We also assess the importance of the first pion production threshold and first excited state of the nucleon, the -resonance (
, I = 3/2). We found both dynamical effects to be quite relevant for distances r between
fm up to
fm in the nn system, the neutron-wall system and in the wall-neutron-wall system, reaching the expected asymptotic limit beyond that. Relevance of our findings to the confinement of ultra cold neutrons inside bottles is discussed.
© SIF, Springer-Verlag GmbH Germany, 2017