Glueballs, hybrid and exotic mesons
We review lattice QCD results for glueballs (including a discussion of mixing with scalar mesons), hybrid mesons and exotic mesons (such as $B_s B_s$ molecules).
hep-ph↗
arXiv subjects
Chris Michael
Publications and source records attributed to Chris Michael.
Mixing of scalar glueballs and flavour-singlet scalar mesons
We discuss in detail the extraction of hadronic mixing strengths from lattice studies. We apply this to the mixing of a scalar glueball and a scalar meson in the quenched approximation. We also measure correlations appropriate for flavour-singlet scalar mesons using dynamical quark configurations from UKQCD. This enables us to compare the results from the quenched study of the mixing with the direct determination of the mixed spectrum. Improved methods of evaluating the disconnected quark diagrams are also presented.
hep-lat↗
Glueballs, hybrid and exotic mesons and string breaking
We review lattice QCD results for glueballs (including a discussion of mixing with scalar mesons), hybrid mesons and exotic mesons (such as $B_s B_s$ molecules). We also discuss string breaking as a mixing between colour flux states and $B \bar{B}$ states.
hep-ph↗
Quarkonia and Hybrids from the Lattice
The status of lattice determinations of quarkonia and hybrid meson spectra is presented and compared with experiment. Both quenched and unquenched results are discussed. Hybrid meson decays are considered.
hep-ph↗
Feasibility study of using the overlap-Dirac operator for hadron spectroscopy
We investigate a number of algorithms that calculate the quark propagators for the overlap-Dirac fermion operator. The QCD simulations were performed at beta = 5.9 with a lattice volume of 16**3*32.
hep-lat↗
Hadronic Spectroscopy from the Lattice: Glueballs and Hybrid Mesons
Lattice QCD determinations appropriate to hadron spectroscopy are reviewed with emphasis on the glueball and hybrid meson states in the quenched approximation. Hybrids are discussed for heavy and for light quarks. The effects of sea quarks (unquenching) are explored.
hep-ph↗
Adiabatic surfaces from the lattice: excited gluonic potentials
I describe the results from lattice studies of probing the vacuum with static colour sources. Topics include (i) Twang the flux tube: string models and hybrid mesons. (ii) Charge up the flux tube: adjoint and sextet sources. (iii) Several sources: how does the colour flux get arranged?
hep-ph↗
Hadron Spectroscopy from the Lattice
Lattice QCD determinations appropriate to hadron spectroscopy are reviewed with emphasis on the glueball and hybrid meson states in the quenched approximation. Hybrids are discussed for heavy and for light quarks. The effects of sea quarks (unquenching) are explored. Heavy-light systems are presented - particularly excited B mesons.
hep-ph↗
Hadronic Physics from the Lattice
Topics covered in this review are the lattice gauge theory approach to the evaluation of non-perturbative hadronic interactions from first principles, particularly applications to glueballs, inter-quark potentials, the running coupling constant and hybrid mesons. Also discussed are the limitations of the quenched approximation.
hep-ph↗
Exotic hadronic states and all-to-all quark propagators
We discuss methods to obtain accurate hadronic spectra with propagating quarks. Comparing the determination of masses for spin-exotic hybrid mesons with glueball mass determinations, we conclude that quark propagators from all sites to all other sites would enable great improvement in the errors. Such propagators are achievable by using stochastic estimators. We discuss previous attempts and present our method for maximal variance reduction. This is a very promising technique and we illustrate it by obtaining the spectrum of ground state and excited B mesons in the limit where the $b$ quark is static.
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Glueballs and Hybrid Mesons
The status of non-perturbative QCD calculations for mesons with gluonic excitation is presented. Lattice results for the glueball spectrum are reviewed. For hybrid mesons, the heavy quark results are summarised and new results are presented for light quarks. Preliminary results for the spectrum of light-quark hybrid mesons indicate substantial mixing with quark model states for non-exotic $J^{PC}$. For the exotic $J^{PC}$ hybrid mesons, the $J^{PC}=1^{-+}$, $0^{+-}$ and $2^{+-}$ states are explored.
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Masses and decay constants of the light mesons in the quenched approximation using the tadpole--improved SW-clover action
We present results for the masses and decay constants of the light mesons in quenched QCD using the standard gluon action and a tadpole--improved SW--clover fermionic action to reduce discretisation errors. The calculation has been carried out at fixed volume and three lattice spacings corresponding to $β=5.7$, $6.0$ and $6.2$. We make comparisons with the conventional SW--clover scheme. We use our results to extract continuum limits and to quantify the size of discretisation errors at smaller $β$-values.
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The QCD Spectrum
Recent results in light hadron spectroscopy are reviewed. Attention is given to the requirements of precision determinations in lattice gauge theory. Different methods for extracting the running coupling constant $α_S$ are compared. Some recent results in determining the nature of the interaction between static quarks are also discussed.
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Glueballs and Hybrid Mesons
We discuss states in the meson spectrum which have explicit gluonic components. Glueballs (with no valence quarks) and hybrid mesons (with valence quarks) are both reviewed. We present in some detail lattice simulation results. ( to appear in proceedings of QCD-20 years, Aachen Workshop)
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The Running Coupling from Lattice Gauge Theory
From an accurate determination of the inter-quark potential, one can study the running coupling constant for a range of $R$-values and hence estimate the scale $Λ_{\msbar} $. Detailed results are presented for $SU(2)$ pure gauge theory to illustrate the method.
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