nucl-th digest · Sep 15, 2022

[Submitted on 14 Sept 2022]

Posterior predictive distributions of neutron-deuteron cross sections

Sean B. S. Miller · Andreas Ekström · Christian Forssén

We quantify the posterior predictive distributions (PPDs) of elastic neutron-deuteron ( $n d$ ) scattering cross sections using nucleon-nucleon ( $N N$ ) interactions from chiral effective field theory ( $χ$ EFT) up to and including next-to-next-to-next-to-leading order (N $^{3}$ LO). These PPDs quantify the spread in $n d$ predictions due to the variability of the low-energy constants (LECs) inferred from $N N$ scattering data. We use the wave-packet continuum discretization method to solve the Alt-Grassberger-Sandhas form of the Faddeev equations for elastic scattering. We draw 100 samples from the PPDs of $n d$ cross sections up to 67 MeV in scattering energy, i.e., in the energy region where the effects of three-nucleon forces are expected to be small. We find that the uncertainty about $N N$ LECs inferred from $N N$ scattering data, when assuming uncorrelated errors, does not translate to significant uncertainty in the low-energy $n d$ continuum. Based on our estimates, the uncertainty of $n d$ predictions are dominated by the $χ$ EFT truncation error, at least below N $^{3}$ LO. At this order, the 90% credible interval of the PPD and the truncation error are comparable, although both are very small on an absolute scale.

Comments:: 10 pages, 6 figures
Subjects:: Nuclear Theory (nucl-th)
arXiv:: 2209.06501 [pdf]

PRC(2023)·3 citations

Probing

Ξ N

interaction through inversion of spin-doublets in

Ξ N α α

nuclei

A new way to study the spin-isospin dependence of the

Ξ N

interaction is explored through the energy levels of

Ξ N α

and

Ξ N α α

systems with

α

being a spectator to attract the

Ξ N

pair without changing its spin-isospin structure. By using the Gaussian expansion method (GEM) with the state-of-the-art

Ξ N

potential obtained from lattice QCD calculations, it is found that

Ξ N α α

has spin-doublet bound states with

J^{π} = 1^{-}

and

2^{-}

in both isospin triplet and singlet channels. The inversion of the

1^{-}

2^{-}

spin-doublet between the iso-triplet and the iso-singlet is found to be strongly correlated with the relative strengths of the

Ξ N

interaction in the

^{11} S_{0},^{13} S_{1},^{31} S_{0}

and

^{33} S_{1}

channels. The

(K^{-}, K^{+})

and

(K^{-}, K^{0})

reactions on the

^{10}

B target are proposed to produce those bound states.

Comments:: 5pages, 5figures
Subjects:: Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:: 2209.06711 [pdf]

PRC(2022)·20 citations

Thursday·September 15, 2022

Posterior predictive distributions of neutron-deuteron cross sections

Probing $Ξ N$ interaction through inversion of spin-doublets in $Ξ N α α$ nuclei

Affiliations

Posterior predictive distributions of neutron-deuteron cross sections

Probing ΞN interaction through inversion of spin-doublets in ΞNαα nuclei

Affiliations

Probing $Ξ N$ interaction through inversion of spin-doublets in $Ξ N α α$ nuclei