Heavy-Light and Doubly-Strange Diquark Spectrum from QCD Laplace Sum-Rules and Diagrammatic Renormalization Methods
Date
2023-09-14
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
0000-0003-3976-1272
Type
Thesis
Degree Level
Doctoral
Abstract
In addition to the conventional $q\bar{q}$ and $qqq$ bound states of quarks $q$, exotic hadrons, such as the four-quark $q\bar{q}q\bar{q}$ and the five-quark $qqqq\bar{q}$ bound states, can be constructed by assuming colour confinement in strong interactions. In particular, one of the possible internal structure for a four-quark state is the tetraquark $[qq][\bar{q}\bar{q}]$, where diquarks $[qq]$ and antidiquarks $[\bar{q}\bar{q}]$ are bound due to the colour force. In this thesis, heavy-light $[Qq]$, where $Q\in\{c, b\}$ (charm, bottom) and $q\in\{u,d,s\}$ (up, down, strange), and doubly-strange $[ss]$ diquarks are examined using QCD Laplace sum-rules. The diquark two-point correlation function is renormalized using diagrammatic renormalization methods for QCD correlation functions that are developed and compared to the conventional renormalization method. It is shown that the mixing of composite operators induced by the conventional renormalization approach is avoided by the diagrammatic renormalization method. The strange quark condensate parameter $\kappa=\langle\bar{s}s\rangle/\langle\bar{n}n\rangle$, where $n\in\{u,d\}$, is shown to have an important role on the $[Qs]$ and $[Qn]$ diquark mass splitting.
Description
Keywords
diquark, diquark mass splitting, heavy-light diquark, doubly-strange diquark, qcd sum-rules, diagrammatic renormalization
Citation
Degree
Doctor of Philosophy (Ph.D.)
Department
Physics and Engineering Physics
Program
Physics