Eur. Phys. J. A (2015) 51: 7
https://doi.org/10.1140/epja/i2015-15007-2

Regular Article - Theoretical Physics

Low-density homogeneous symmetric nuclear matter: Disclosing dinucleons in coexisting phases

¹ Department of Physics, University of Chile, Av. Blanco Encalada 2008, Santiago, Chile
² CEA, DAM, F-91297, Arpajon, France

^* e-mail: arellano@dfi.uchile.cl

Received: 27 October 2014
Revised: 12 January 2015
Accepted: 14 January 2015
Published online: 28 January 2015

Abstract

The effect of in-medium dinucleon bound states on self-consistent single-particle fields in Brueckner, Bethe and Goldstone theory is investigated in symmetric nuclear matter at zero temperature. To this end, dinucleon bound state occurences in the ¹ S ₀ and ³ SD ₁ channels are explicitly accounted for --within the continuous choice for the auxiliary fields-- while imposing self-consistency in Brueckner-Hartree-Fock approximation calculations. Searches are carried out at Fermi momenta in the range fm^-1, using the Argonne bare nucleon-nucleon potential without resorting to the effective-mass approximation. As a result, two distinct solutions meeting the self-consistency requirement are found with overlapping domains in the interval 0.130 fm^-1 0.285 fm^-1, corresponding to mass densities between and g cm^-3. Effective masses as high as three times the nucleon mass are found in the coexistence domain. The emergence of superfluidity in relationship with BCS pairing gap solutions is discussed.