Speaker
Description
One of the challenges faced while studying the nuclear many-body problem is the nature of the nucleon-nucleon interaction. In recent decades, models for the nucleon-nucleon interaction were produced from a power counting expansion in Chiral Effective Field theory (EFT). As a result, these modern nuclear interactions have an advantage over previously used phenomenological potentials, since they have a connection to the symmetries of the underlying theory of QCD [1]. To investigate the nuclear many-body problem, we employ an ab initio approach. Quantum Monte Carlo (QMC) consists of a family of powerful stochastic methods for solving the many-body Schrodinger equation [2]. QMC methods provide very accurate results, at the cost of being computationally expensive. In addition to their accuracy, QMC methods have the benefit that we can build the appropriate physics, such as pairing, directly into them. Combining these two tools, non-perturbative QMC methods and the perturbative Chiral-EFT derived nucleon-nucleon interaction, leads to an obvious contradiction. Historically it has been very difficult to calculate perturbative corrections higher than first order in most ab initio methods. However, our recent work [3] has made significant progress in calculating the second-order perturbative correction in a QMC context. To show this, we explore a variety of low-density neutron matter systems that have a direct application to neutron-rich systems such as the inner crust of neutron stars. In addition, we also apply this new method to probe the perturbativeness of modern chiral EFT potentials and discuss the implications for nuclear many-body physics.
[1] R. Machleidt and D.R. Entem, Chiral Effective Field Theory and Nuclear Forces, Phys. Rep. 503, 1 (2011).
[2] J. Carlson et al., Quantum Monte Carlo Methods for Nuclear Physics, Rev. Mod. Phys. 87, 1067 (2015).
[3] R. Curry et al., Second-Order Perturbation Theory in Continuum Quantum Monte Carlo Calculations, arXiv:2302.07285, (2023).
| Keyword-1 | Quantum Monte Carlo |
|---|---|
| Keyword-2 | Chiral Effective Field Theory |
| Keyword-3 | Neutron Stars |
