Doctor of Philosophy (Ph.D.)
In the present work, spectroscopy and interactions of hadrons containing heavy quarks is investigated. In particular, a focus is placed on properties of exotic heavy hadronic states, including doubly and triply heavy baryons and doubly heavy tetraquark states. The framework in which these calculations are carried out is provided by lattice quantum chromodynamics, a discrete formulation of the modern theory of the strong interaction. The main body of the thesis had two main project focuses. For the first project, an extensive calculation of the mass spectrum of doubly and triply heavy baryons including both charm and bottom quarks is carried out. The wide range of quark masses in these systems require that the various flavors of quarks be treated with different lattice actions. We use domain wall fermions for 2+1 flavors (up down and strange) of sea and valence quarks, a relativistic heavy quark action for the charm quarks, and non-relativistic QCD for the heavier bottom quarks. The calculation of the ground state spectrum is presented and compared to recent models. For the second project, the interaction potential of two heavy-light mesons in lattice QCD is used to study the existence of tetraquark bound states. The interaction potential of the tetraquark system is calculated on the lattice with 2+1 flavors of dynamical fermions with lattice interpolating fields constructed using colorwave propagators. These propagators provide a method for constructing all-to-all spatially smeared the interpolating fields, a technique which allows for a better overlap with the ground state wavefunction as well as reduced statistical noise. Potentials are extracted for 24 distinct channels, and are fit with a phenomenological non-relativistic quark model potential, from which a determination of the existence of bound states is made via numerical solution of the two body radial Schrodinger equation.
© The Author
Brown, Zachary S., "Heavy flavor interactions and spectroscopy from lattice quantum chromodynamics" (2015). Dissertations, Theses, and Masters Projects. Paper 1539623998.