Over the past twenty years, one has seen remarkable progress in ab initio studies of nuclear structure and reactions with chiral nuclear forces. In a series of recent studies [1-5], we have shown that it is possible to construct chiral nuclear forces using covariant baryon chiral perturbation theory, which enjoy a number of appealing features. For instance, they are manifestly covariant and therefore can be applied in ab initio studies based on covariant frameworks, such as the Dirac-Brueckner Hartree-Fock approach. Second, they converge relatively faster than their non-relativistic counterparts both in the two-body [1-5] and in the three-body sector [6]. In this talk, we explain in detail how they are built from covariant baryon chiral perturbation theory [1,2], highlight their applications to lattice QCD simulations in the hyperon-nucleon/hyperon sector [3,4], and show the recent progress in going to higher chiral orders in this endeavor [5,7].
References:
1) Leading order relativistic chiral nucleon-nucleon interaction, Xiu-Lei Ren, Kai-Wen Li, Li-Sheng Geng, Bing-Wei Long, Peter Ring, Jie Meng, arXiv:1611.08475 [nucl-th], Chin.Phys. C42 (2018), 014103.
2) Leading order relativistic hyperon-nucleon interactions in chiral effective field theory, Kai-Wen Li, Xiu-Lei Ren, Li-Sheng Geng, Bing-Wei Long, arXiv:1612.08482 [nucl-th], Chin.Phys. C42 (2018), 014105.
3) Strangeness S=−1 hyperon-nucleon interactions: Chiral effective field theory versus lattice QCD, Jing Song, Kai-Wen Li, Li-Sheng Geng, arXiv:1802.04433 [nucl-th], Phys.Rev. C97 (2018), 065201.
4) Strangeness $S=-2$ baryon-baryon interactions in relativistic chiral effective field theory, Kai-Wen Li, Tetsuo Hyodo, Li-Sheng Geng, arXiv:1809.03199 [nucl-th], Phys.Rev. C98 (2018), 065203.
5) Covariant chiral nucleon-nucleon contact Lagrangian up to order $\mathcal{O}(q^4)$, Yang Xiao, Li-Sheng Geng, Xiu-Lei Ren, arXiv:1812.03005 [nucl-th].
6) Short-range three-nucleon interaction from A=3 data and its hierarchical structure, L. Girlanda, A. Kievsky, M. Viviani, L.E. Marcucci, arXiv:1811.09398 [nucl-th].
7）Meson-baryon scattering up to the next-to-next-to-leading order in covariant baryon chiral perturbation theory, Jung-Xu Lu, Li-Sheng Geng, Xiu-Lei Ren, Meng-Lin Du, arXiv:1812.03799 [nucl-th], Phys.Rev. D99 (2019) 054024.