E-Thesis 253 views 74 downloads
Meson Masses in the Unquenched Quark Model / JACK KENNELLY
Swansea University Author: JACK KENNELLY
Abstract
A novel approach to calculating coupled-channel effects for bottomonium in the 3P0 framework using realistic wavefunctions is introduced in which the physical state is expanded in a basis set of harmonic oscillators. Other techniques of solving the unquenched system are also presented including pertu...
| Published: |
Swansea
2022
|
|---|---|
| Institution: | Swansea University |
| Degree level: | Master of Research |
| Degree name: | MSc by Research |
| Supervisor: | Burns, Timothy |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa59927 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Abstract: |
A novel approach to calculating coupled-channel effects for bottomonium in the 3P0 framework using realistic wavefunctions is introduced in which the physical state is expanded in a basis set of harmonic oscillators. Other techniques of solving the unquenched system are also presented including perturbative, simple harmonic oscillator and unique valence approximations. The resulting (spin-averaged) mass shifts are calculated for an nS → 1S +1S transition and compared across the separate methods. It is determined that the largest effect on the mass shift across the various approaches is the accu-rate treatment of the wavefunction, which causes significant deviations from the simple harmonic oscillator approximation near threshold. It is also found that the inclusion of mixing between valence states due to meson loops has no effect at ground state energies but induces small differences at higher lying states. While conclusions are drawn about the relative effect each of the methods presented have on determining the mass shift due to unquench-ing, further research is suggested for other transitions to be assured in such conclusions. |
|---|---|
| Keywords: |
Meson, Quark, Unquenched, Harmonic Oscillator |
| College: |
Faculty of Science and Engineering |