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Title: Final Report for Nuclear Lattice Simulations with Chiral Effective Field Theory

Abstract

The nuclear lattice program at North Carolina State University addresses the nuclear many-body problem by applying non-perturbative lattice methods directly to hadrons. In this approach nucleons are treated as point particles on a lattice with a lattice spacing between 1 and 4 fm. The low energy interactions of the nucleons are governed by effective field theory and the unknown operator coefficients are determined by fitting to few-body scattering data. By using hadronic degrees of freedom and concentrating on low-energy physics, it is possible to probe larger volumes, lower temperatures, and far greater numbers of nucleons than in lattice QCD. In some cases the sign/complex phase problem can even be completely eliminated.

Authors:
Publication Date:
Research Org.:
North Carolina State University
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
899857
DOE Contract Number:
FG02-04ER41335
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; DEGREES OF FREEDOM; HADRONS; MANY-BODY PROBLEM; NUCLEONS; PHYSICS; PROBES; QUANTUM CHROMODYNAMICS; SCATTERING; nuclear lattice simulation effective field theory nuclear matter neutron matter unitary limit

Citation Formats

Dean Lee. Final Report for Nuclear Lattice Simulations with Chiral Effective Field Theory. United States: N. p., 2007. Web. doi:10.2172/899857.
Dean Lee. Final Report for Nuclear Lattice Simulations with Chiral Effective Field Theory. United States. doi:10.2172/899857.
Dean Lee. Mon . "Final Report for Nuclear Lattice Simulations with Chiral Effective Field Theory". United States. doi:10.2172/899857. https://www.osti.gov/servlets/purl/899857.
@article{osti_899857,
title = {Final Report for Nuclear Lattice Simulations with Chiral Effective Field Theory},
author = {Dean Lee},
abstractNote = {The nuclear lattice program at North Carolina State University addresses the nuclear many-body problem by applying non-perturbative lattice methods directly to hadrons. In this approach nucleons are treated as point particles on a lattice with a lattice spacing between 1 and 4 fm. The low energy interactions of the nucleons are governed by effective field theory and the unknown operator coefficients are determined by fitting to few-body scattering data. By using hadronic degrees of freedom and concentrating on low-energy physics, it is possible to probe larger volumes, lower temperatures, and far greater numbers of nucleons than in lattice QCD. In some cases the sign/complex phase problem can even be completely eliminated.},
doi = {10.2172/899857},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Feb 26 00:00:00 EST 2007},
month = {Mon Feb 26 00:00:00 EST 2007}
}

Technical Report:

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  • We study nuclear and neutron matter by combining chiral effective field theory with nonperturbative lattice methods. In our approach, nucleons and pions are treated as point particles on a lattice. This allows us to probe larger volumes, lower temperatures, and greater nuclear densities than in lattice QCD. The low-energy interactions of these particles are governed by chiral effective theory, and operator coefficients are determined by fitting to zero temperature few-body scattering data. The leading dependence on the lattice spacing can be understood from the renormalization group and absorbed by renormalizing operator coefficients. In this way, we have a realistic simulationmore » of many-body nuclear phenomena with no free parameters, a systematic expansion, and a clear theoretical connection to QCD. We present results for hot neutron matter at temperatures 20-40 MeV and densities below twice the nuclear matter density.« less
  • The research supported by this grant is aimed at probing the limits of the Standard Model through precision low-energy nuclear physics. The work of the PI (AWL) and additional personnel is to provide theory input needed for a number of potentially high-impact experiments, notably, hadronic parity violation, Dark Matter direct detection and searches for permanent electric dipole moments (EDMs) in nucleons and nuclei. In all these examples, a quantitative understanding of low-energy nuclear physics from the fundamental theory of strong interactions, Quantum Chromo-Dynamics (QCD), is necessary to interpret the experimental results. The main theoretical tools used and developed in thismore » work are the numerical solution to QCD known as lattice QCD (LQCD) and Effective Field Theory (EFT). This grant is supporting a new research program for the PI, and as such, needed to be developed from the ground up. Therefore, the first fiscal year of this grant, 08/01/2014-07/31/2015, has been spent predominantly establishing this new research effort. Very good progress has been made, although, at this time, there are not many publications to show for the effort. After one year, the PI accepted a job at Lawrence Berkeley National Laboratory, so this final report covers just a single year of five years of the grant.« less
  • The first successful application of a microscopic analogy to create a skeleton cellular automaton and analyze it with statistical mechanical tools, was the work of Frisch, Hasslacher and Pomeau on the Navier-Stokes equation in two and three dimensions. This has become a very large research area with lattice gas models and methods being used for both fundamental investigations into the foundations of statistical mechanics and a large number of diverse applications. This present research was devoted to enlarging the fundamental scope of lattice gas models and proved successful. Since the beginning of this proposal, cellular automata have been constructed formore » statistical mechanical models, fluids, diffusion and shock systems in fundamental investigations. In applied areas, there are now excellent lattice gas models for complex flows through porous media, chemical reaction and combustion dynamics, multiphase flow systems, and fluid mixtures with natural boundaries. With extended cellular fluid models, one can do problems with arbitrary pairwise potentials. Recently, these have been applied to such problems as non-newtonian or polymeric liquids and a mixture of immiscible fluids passing through fractal or spongelike media in two and three dimensions. This proposal has contributed to and enlarged the scope of this work.« less
  • The first successful application of a microscopic analogy to create a skeleton cellular automaton and analyze it with statistical mechanical tools, was the work of Frisch, Hasslacher and Pomeau on the Navier-Stokes equation in two and three dimensions. This has become a very large research area with lattice gas models and methods being used for both fundamental investigations into the foundations of statistical mechanics and a large number of diverse applications. This present research was devoted to enlarging the fundamental scope of lattice gas models and proved quite successful. Since the beginning of this proposal, cellular automata have been constructedmore » for statistical mechanical models, fluids, diffusion and shock systems in fundamental investigations. In applied areas, there are now excellent lattice gas models for complex flows through porous media, chemical reaction and combustion dynamics, multiphase flow systems, and fluid mixtures with natural boundaries. With extended cellular fluid models, one can do problems with arbitrary pairwise potentials. Recently, these have been applied to such problems as non-newtonian or polymeric liquids and a mixture of immiscible fluids passing through fractal or spongelike media in two and three dimensions. This proposal has contributed to and enlarged the scope of this work.« less
  • The VIBRA-6 computer program is a digital computer program developed to deter the response of aircraft to nuclear explosions when flying at subsonic speeds. It is similar to the VIBRA-4 program but uses the latest Doublet-Lattice Method for obtaining subsonic aerodynamic forces for arbitrary lifting surface-body configurations. The Doublet-Lattice procedure has been extended to account for the moving blast wave by considering it as a traveling gust. The nuclear blast representation remains the same as that used in the VIBRA-4 program but the method of solution of the equations of motion has been changed from that of numerical integration ofmore » quasi-steady equations of motion to a Fourier transform procedure to move from frequency domain solutions to time history solutions. The concept of dynamic core has been introduced to the program thus removing any restrictions on the size of the aircraft idealization which can be analyzed.« less