# Relativistic Few-Body Hadronic Physics Calculations

## Abstract

The goal of this research proposal was to use ``few-body'' methods to understand the structure and reactions of systems of interacting hadrons (neutrons, protons, mesons, quarks) over a broad range of energy scales. Realistic mathematical models of few-hadron systems have the advantage that they are sufficiently simple that they can be solved with mathematically controlled errors. These systems are also simple enough that it is possible to perform complete accurate experimental measurements on these systems. Comparison between theory and experiment puts strong constraints on the structure of the models. Even though these systems are ``simple'', both the experiments and computations push the limits of technology. The important property of ``few-body'' systems is that the ``cluster property'' implies that the interactions that appear in few-body systems are identical to the interactions that appear in complicated many-body systems. Of particular interest are models that correctly describe physics at distance scales that are sensitive to the internal structure of the individual nucleons. The Heisenberg uncertainty principle implies that in order to be sensitive to physics on distance scales that are a fraction of the proton or neutron radius, a relativistic treatment of quantum mechanics is necessary. The research supported by this grant involvedmore »

- Authors:

- Univ. of Iowa, Iowa City, IA (United States)

- Publication Date:

- Research Org.:
- Univ. of Iowa, Iowa City, IA (United States)

- Sponsoring Org.:
- USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)

- OSTI Identifier:
- 1257842

- Report Number(s):
- DOE-IOWA-40286-1

- DOE Contract Number:
- FG02-86ER40286

- Resource Type:
- Technical Report

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 73 NUCLEAR PHYSICS AND RADIATION PHYSICS

### Citation Formats

```
Polyzou, Wayne.
```*Relativistic Few-Body Hadronic Physics Calculations*. United States: N. p., 2016.
Web. doi:10.2172/1257842.

```
Polyzou, Wayne.
```*Relativistic Few-Body Hadronic Physics Calculations*. United States. doi:10.2172/1257842.

```
Polyzou, Wayne. Mon .
"Relativistic Few-Body Hadronic Physics Calculations". United States.
doi:10.2172/1257842. https://www.osti.gov/servlets/purl/1257842.
```

```
@article{osti_1257842,
```

title = {Relativistic Few-Body Hadronic Physics Calculations},

author = {Polyzou, Wayne},

abstractNote = {The goal of this research proposal was to use ``few-body'' methods to understand the structure and reactions of systems of interacting hadrons (neutrons, protons, mesons, quarks) over a broad range of energy scales. Realistic mathematical models of few-hadron systems have the advantage that they are sufficiently simple that they can be solved with mathematically controlled errors. These systems are also simple enough that it is possible to perform complete accurate experimental measurements on these systems. Comparison between theory and experiment puts strong constraints on the structure of the models. Even though these systems are ``simple'', both the experiments and computations push the limits of technology. The important property of ``few-body'' systems is that the ``cluster property'' implies that the interactions that appear in few-body systems are identical to the interactions that appear in complicated many-body systems. Of particular interest are models that correctly describe physics at distance scales that are sensitive to the internal structure of the individual nucleons. The Heisenberg uncertainty principle implies that in order to be sensitive to physics on distance scales that are a fraction of the proton or neutron radius, a relativistic treatment of quantum mechanics is necessary. The research supported by this grant involved 30 years of effort devoted to studying all aspects of interacting two and three-body systems. Realistic interactions were used to compute bound states of two- and three-nucleon, and two- and three-quark systems. Scattering observables for these systems were computed for a broad range of energies - from zero energy scattering to few GeV scattering, where experimental evidence of sub-nucleon degrees of freedom is beginning to appear. Benchmark calculations were produced, which when compared with calculations of other groups provided an essential check on these complicated calculations. In addition to computing bound state properties and scattering cross section, we also computed electron scattering cross sections in few-nucleon and few-quark systems, which are sensitive to the electric currents in these systems. We produced the definitive review on article on relativistic quantum mechanics, which and been used by many groups. In addition we developed and tested many computational techniques are used by other groups. Many of these techniques have applications in other areas of physics. The research benefited by collaborations with physicists from many different institutions and countries. It also involved working with seventeen undergraduate and graduate students.},

doi = {10.2172/1257842},

journal = {},

number = ,

volume = ,

place = {United States},

year = {Mon Jun 20 00:00:00 EDT 2016},

month = {Mon Jun 20 00:00:00 EDT 2016}

}