Frontiers in Nuclear Lattice EFT: From Ab Initio Nuclear Structure to Reactions

In this talk, I will present an overview of recent advances in nuclear lattice simulations, focusing on how the recently developed N3LO lattice action bridges the gap between QCD and nuclear interactions, enabling the formulation of a modern theory of nuclear forces. More specifically, I will discuss the determination of three-nucleon interactions, which has led to highly precise predictions...

I will present the alpha-alpha scattering results using the latest improved NLEFT interaction, including wavefunction matching, at N3LO. This will be an improvement to our previous results, where we had only up to N2LO and with a different interaction.

Big Bang or primordial nucleosynthesis (BBN) provides a fine laboratory for testing theories beyond the standard model. I present recent work on finding constraints on the variation of fundamental parameters like the Higgs VEV and the strange quark condensate from BBN. In order to match the precision set by experiment for primordial abundances, we need to further improve our theoretical...

We introduce a new method, referred to as the persistent state method, for determining few-body resonance poles in a finite volume. The effectiveness of the method is demonstrated through explicit examples covering both continuum and lattice setups, as well as two- and three-body resonance cases.

Nuclear charge radii are among the most fundamental properties of atomic nuclei. In nuclear lattice effective field theory, charge radii are typically calculated using the pinhole method, where an $A$-body density operator ($A$ being the mass number) is inserted at mid-time during the imaginary time evolution. However, this $A$-body density operator introduces significant sign oscillations,...

In this report, we focus on 22Si, likely the lightest bound nucleus with Tz=−3, using Nuclear Lattice Effective Field Theory (NLEFT) with chiral forces. Our calculations agree with existing data and predict it as a proton-dripline nucleus, along with its 2+ state, radius, and spatial properties. Using nucleon ordering operators, we reveal nucleon spatial arrangement and localization, linked to...

We study Carbon and Oxygen isotopes in NLEFT by using Wave Function Matching method with high fidelity Hamiltonian.

We present calculations of nuclear magnetic moments for light nuclei and aluminum isotopes using nuclear lattice effective field theory with the N3LO chiral interaction. Both one- and two-body electromagnetic current effects are included in the calculations. For all nuclei considered, the lattice results are generally consistent with experimental data. We find that the contribution from...

Experimental exploration of neutron dripline is very challenging, and neon is the heaviest nucleus measured neutron dripline experimentally. Prediction of dripline heavier nuclei than neon is currently depends on theoretical approaches. However, there exist strong model-dependence in the prediction of the dripline in theoretical approach. Nuclear Lattice Effective Field Theory is one of the ab...

The equation of state (EoS) of neutron matter plays a decisive role to understand the neutron star properties and the gravitational waves from neutron star mergers. At sufficient densities, the appearance of hyperons generally softens the EoS, leading to a reduction in the maximum mass of neutron stars well below the observed values of about 2 solar masses. Even though repulsive three-body...

Understanding the strong interaction beyond the up and down quark sector is crucial for an accurate and comprehensive description of nuclear forces. The inclusion of hyperons, in particular the $\Lambda$, extends the nuclear chart to a third dimension. We therefore present an extension of the NLEFT framework to the strangeness sector. In particular we focus on light to medium mass hypernuclei...

Chiral interactions provide a systematic approach to baryonic interactions resulting in a high accuracy description of NN and YN interactions [1,2]. For a similar description of many-baryon systems at least 3BFs are necessary which can be consistently obtained using chiral effective field theory. In this contribution, I report on our recent progress to further constrain these interactions...

Quantum Monte Carlo approaches based upon Feynman path integrals are powerful for addressing quantum many-body problems. However, they generally suffer from the “fermion-sign problem” that leads to exponential scaling of the computation effort with system size. As an alternative, the variational Monte Carlo (VMC) approach avoids such sign problems, but the challenge becomes how to construct an...

We employ the nuclear lattice effective field theory (NLEFT), an efficient tool for nuclear ab. initio calculations, to solve the asymmetric multi-hadron systems. We take the DD∗K three-body system as an illustration to demonstrate the capability of the method. Here the two-body chiral interactions between D, D* and K are regulated with a soft lattice regulator and calibrated with the
binding...

How the nuclear magicity emerge from the underlying nuclear forces? Conventional understanding is based on the picture of the mean field, in which the nucleons move individually around onion-like orbits. Such a picture lacks the important many-body correlations and the connection to the bare nucleon-nucleon forces is obscure. We present a lattice nuclear force model capturing the essential...

Constructing fast and accurate surrogate models is a key ingredient for making robust predictions in many topics. We present a new model, the Multiparameter Eigenvalue Problem (MEP) emulator. Our new emulator connects emulators and can make predictions directly from observables to observables. We demonstrate that our MEP emulator can connect both Eigenvector Continuation (EC) and Parametric...

Nucleon pion production is an important process to study the low energy features, especially the chiral behaviours of QCD. The process receive strong attention since 1950s from experimental side, and would still play a crucial role to control the systematic effects in future neutrino-nucleus scattering experiments. Theoretically, though Chiral Perturbation Theory (Chipt) has given fruitful...