Hypernuclear no-core shell model

0491097 - ÚJF 2019 RIV US eng J - Journal Article
Wirth, R. - Gazda, Daniel - Navratil, P. - Roth, R.
Hypernuclear no-core shell model.
Physical Review C. Roč. 97, č. 6 (2018), č. článku 064315. ISSN 2469-9985. E-ISSN 2469-9993
R&D Projects: GA ČR(CZ) GA15-04301S
Institutional support: RVO:61389005
Keywords : no-core shell model * symmetries * four-body system
OECD category: Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect)
Impact factor: 3.132, year: 2018

We extend the no-core shell model (NCSM) methodology to incorporate strangeness degrees of freedom and apply it to single-Lambda hypernuclei. After discussing the transformation of the hyperon-nucleon (YN) interaction into the harmonic-oscillator (HO) basis and the similarity renormalization group transformation applied to it to improve model-space convergence, we present two complementary formulations of the NCSM, one that uses relative Jacobi coordinates and symmetry-adapted basis states to fully exploit the symmetries of the hypernuclear Hamiltonian and one working in a Slater determinant basis of HO states where antisymmetrization and computation of matrix elements is simple and to which an importance-truncation scheme can be applied. For the Jacobi-coordinate formulation, we give an iterative procedure for the construction of the antisymmetric basis for arbitrary particle number and present the formulas used to embed two-and three-baryon interactions into the many-body space. For the Slater-determinant formulation, we discuss the conversion of the YN interaction matrix elements from relative to single-particle coordinates, the importance-truncation scheme that tailors the model space to the description of the low-lying spectrum, and the role of the redundant center-of-mass degrees of freedom. We conclude with a validation of both formulations in the four-body system, giving converged ground-state energies for a chiral Hamiltonian, and present a short survey of the A <= 7 hyperhelium isotopes.
Permanent Link: http://hdl.handle.net/11104/0285171