Application of chiral nuclear forces to light nuclei

In these proceedings, we discuss the current status of nuclear bound state predictions based on chiral nuclear interactions. Results of ordinary $s$- and $p$-shell nuclei and light hypernuclei are shown.Comment: 12 pages, 2 figures, corrected typos in Table 5, version as publishe

Solution of the Faddeev-Yakubovsky equations using realistic NN and 3N interaction

We solve the Faddeev-Yakubovsky equations for 3N and 4N bound states based on the most modern realistic nucleon-nucleon interactions. We include different realistic 3N forces. It is shown that all 3N force models can remove the underbinding of the triton and alpha-particle which one obtains with existing NN interactions. The agreement of theoretical predictions and the experimental binding energy is quite good and there is little room left for the action of four-nucleon forces in the alpha-particle. The effect of 3N forces on the wave function is investigated.Comment: 4 pages, to appear in the proceedings of the "European Few-Body Conference", Evora 200

Comparative study of hyperon-nucleon interactions of quark model and chiral effective field theory by low-momentum equivalent interactions and GG matrices

Hyperon-nucleons interactions constructed by two frameworks, the Kyoto-Niigata SU$_6$ quark model and the chiral effective field theory, are compared by investigating equivalent interactions in a low-momentum space and in addition by calculating hyperon single-particle potentials in the lowest-order Brueckner theory in symmetric nuclear matter. Two descriptions are shown to give similar matrix elements in most channels after renormalizing high momentum components. Although the range of the $\Lambda N$ interaction is different in two potentials, the $\Lambda$ single-particle potential in nuclear matter is very similar. The $\Sigma$-nucleus and $\Xi$-nucleus potentials are also found to be similar. These predictions are to be confronted with forthcoming experimental data.Comment: 8 pages, 7 figures. To appear in Phys. Rev.

Permanent Electric Dipole Moments of Single-, Two-, and Three-Nucleon Systems

A nonzero electric dipole moment (EDM) of the neutron, proton, deuteron or helion, in fact, of any finite system necessarily involves the breaking of a symmetry, either by the presence of external fields (i.e. electric fields leading to the case of induced EDMs) or explicitly by the breaking of the discrete parity and time-reflection symmetries in the case of permanent EDMs. We discuss two theorems describing these phenomena and report about the cosmological motivation for an existence of CP breaking beyond what is generated by the Kobayashi-Maskawa mechanism in the Standard Model and what this might imply for the permanent electric dipole moments of the nucleon and light nuclei by estimating a window of opportunity for physics beyond what is currently known. Recent - and in the case of the deuteron even unpublished - results for the relevant matrix elements of nuclear EDM operators are presented and the relevance for disentangling underlying New Physics sources are discussed.Comment: 20 pages, chapter for the memorial book "Gerry Brown 90", final version, some typos correcte

Investigating Neutron Polarizabilities through Compton Scattering on 3^3He

We examine manifestations of neutron electromagnetic polarizabilities in coherent Compton scattering from the Helium-3 nucleus. We calculate $\gamma ^3$He elastic scattering observables using chiral perturbation theory to next-to-leading order (${\mathcal O}(e^2 Q)$). We find that the unpolarized differential cross section can be used to measure neutron electric and magnetic polarizabilities, while two double-polarization observables are sensitive to different linear combinations of the four neutron spin polarizabilities. [Note added in 2018] An erratum for this paper has been posted as arXiv:1804.01206. Overall conclusions are unchanged, but quantitative results are affected appreciably.Comment: 4 pages, 4 figures; version published in Phys. Rev. Let

First-principle calculations of Dark Matter scattering off light nuclei

We study the scattering of Dark Matter particles off various light nuclei within the framework of chiral effective field theory. We focus on scalar interactions and include one- and two-nucleon scattering processes whose form and strength are dictated by chiral symmetry. The nuclear wave functions are calculated from chiral effective field theory interactions as well and we investigate the convergence pattern of the chiral expansion in the nuclear potential and the Dark Matter-nucleus currents. This allows us to provide a systematic uncertainty estimate of our calculations. We provide results for ${}^2$H, ${}^3$H, and ${}^3$He nuclei which are theoretically interesting and the latter is a potential target for experiments. We show that two-nucleon currents can be systematically included but are generally smaller than predicted by power counting and suffer from significant theoretical uncertainties even in light nuclei. We demonstrate that accurate high-order wave functions are necessary in order to incorporate two-nucleon currents. We discuss scenarios in which one-nucleon contributions are suppressed such that higher-order currents become dominant