Spin structure of heavy-quark hybrids

Abstract

A unique feature of quantum chromodynamics (QCD), the theory of strong interactions, is the possibility for gluonic degrees of freedom to participate in the construction of physical hadrons, which are color singlets, in an analogous manner to valence quarks. Hadrons with no valence quarks are called glueballs, while hadrons where both gluons and valence quarks combine to form a color singlet are called hybrids. The unambiguous identification of such states among the experimental hadron spectrum has been thus far not possible. Glueballs are particularly difficult to establish experimentally since the lowest lying ones are expected to strongly mix with conventional mesons. On the other hand, hybrids should be easier to single out because the set of quantum numbers available to their lowest excitations may be exotic, i.e., not realized in conventional quark-antiquark systems. Particularly promising for discovery appear to be heavy hybrids, which are made of gluons and a heavy-quark-antiquark pair (charm or bottom). In the heavy-quark sector systematic tools can be used that are not available in the light-quark sector. In this paper we use a nonrelativistic effective field theory to uncover for the first time the full spin structure of heavy-quark hybrids up to $1/m^2$-terms in the heavy-quark-mass expansion. We show that such terms display novel characteristics at variance with our consolidated experience on the fine and hyperfine splittings in atomic, molecular and nuclear physics. We determine the nonperturbative contributions to the matching coefficients of the effective field theory by fitting our results to lattice-QCD determinations of the charmonium hybrid spectrum and extrapolate the results to the bottomonium hybrid sector where lattice-QCD determinations are still challenging.

arXiv comment10 pages, 3 figures. Updated version including the corrections in the erratum of Journal version. Two additional operators included, figures and analysis updated

References in corpus (47)

• Observation of a narrow charmonium-like state in exclusive B+ -> K+ pi+pi- J/psi decays
• Observation of a New Narrow Charmonium State in Exclusive B+-->K+ pi+pi- J/psi Decays
• Heavy quarkonium: progress, puzzles, and opportunities
• Heavy-Quark QCD Exotica
• Potential NRQCD: an effective theory for heavy quarkonium
• Effective field theories for heavy quarkonium
• QCD and strongly coupled gauge theories: challenges and perspectives
• Observation of String Breaking in QCD
• Physics Opportunities with the 12 GeV Upgrade at Jefferson Lab
• Excited and exotic charmonium spectroscopy from lattice QCD
• Fine Structure of the QCD String Spectrum
• Static potentials and glueball masses from QCD simulations with Wilson sea quarks
• Ab Initio Study of Hybrid b-bar-gb Mesons
• Born-Oppenheimer Approximation for the XYZ Mesons
• Charmonium excited state spectrum in lattice QCD
• Determination of the bottom quark mass from the ${\rm Y}(1S)$ system
• Gluon excitations of the static quark potential and the hybrid quarkonium spectrum
• The QCD Potential at $O(1/m)$
• QCD phenomenology of static sources and gluonic excitations at short distances
• Quarkonium Hybrids with Nonrelativistic Effective Field Theories
• Hadrons with a heavy colour-adjoint particle
• Excited and exotic charmonium, $D_s$ and $D$ meson spectra for two light quark masses from lattice QCD
• Heavy quarkonium hybrids from Coulomb gauge QCD
• A New Hadron Spectroscopy
• String breaking by light and strange quarks in QCD
• Heavy Quarkonium Hybrids: Spectrum, Decay and Mixing
• Issues and Opportunities in Exotic Hadrons
• Measurements of $\psi (2S)$ and $X(3872)\to J/\psi {\pi }^{+}{\pi }^{-}$ production in $pp$ collisions at $\sqrt{s}=8$ TeV with the ATLAS detector
• Precision computation of hybrid static potentials in SU(3) lattice gauge theory
• Poincare' invariance constraints on NRQCD and potential NRQCD
• The Born-Oppenheimer approximation in an effective field theory language
• Hadro-quarkonium from Lattice QCD
• Charmonium spectroscopy and mixing with light quark and open charm states from nF=2 lattice QCD
• On two- and three-body descriptions of hybrid mesons
• Semirelativistic potential model for glueball states
• Mass Spectrum of Heavy Quarkonium Hybrids
• Effective string theory constraints on the long distance behavior of the subleading potentials
• Heavy Hybrids with Constituent Gluons
• Selection Rules for Hadronic Transitions of XYZ Mesons
• Axial Vector $J^{PC}=1^{++}$ Charmonium and Bottomonium Hybrid Mass Predictions with QCD Sum-Rules
• Mass Predictions for Pseudoscalar $J^{PC}=0^{-+}$ Charmonium and Bottomonium Hybrids in QCD Sum-Rules
• The Hadronic Transitions $Upsilon(2S)\to Upsilon(1S)$
• Coulomb energy and gluon distribution in the presence of static sources
• Novel implementation of the multipole expansion to quarkonium hadronic transitions
• Quarkonium Decays and Light Quark Masses
• More nonperturbative corrections to the fine and hyperfine splitting in the heavy quarkonium
• Contents of LAT97 Proceedings

Cited by in corpus (39)

• The $XYZ$ states: experimental and theoretical status and perspectives
• 50 Years of Quantum Chromodynamics
• Precision computation of hybrid static potentials in SU(3) lattice gauge theory
• Masses of Doubly Heavy Tetraquarks with Error Bars
• QCD spin effects in the heavy hybrid potentials and spectra
• Novel approaches in Hadron Spectroscopy
• Exotic to standard bottomonium transitions
• Nonrelativistic effective field theory for heavy exotic hadrons
• One Born$-$Oppenheimer Effective Theory to rule them all: hybrids, tetraquarks, pentaquarks, doubly heavy baryons and quarkonium
• Hybrid static potentials in SU(3) lattice gauge theory at small quark-antiquark separations
• Bottomonium resonances with $I=0$ from lattice QCD correlation functions with static and light quarks
• The Dynamical Diquark Model: Fine Structure and Isospin
• Excited and exotic bottomonium spectroscopy from lattice QCD
• Effective field theory for double heavy baryons at strong coupling
• Towards the discovery of novel $B_c$ states: radiative and hadronic transitions
• Tetraquark systems $\bar{b}b\bar{d}u$ in the static limit and lattice QCD
• Effective QCD string and doubly heavy baryons
• Lattice gauge theory computation of the static force
• Heavy hybrid decays to quarkonia
• Heavy Hybrid Decays in a Constituent Gluon Model
• Hyperfine splittings of heavy quarkonium hybrids
• Conventional and Hybrid $B_c$ Mesons in an Extended Potential Model
• Novel implementation of the multipole expansion to quarkonium hadronic transitions
• QCD Static Force in Gradient Flow
• Why quarkonium hybrid coupling to two S-wave heavy-light mesons is not suppressed
• The nature of ${\chi }_{c1}\left(3872\right)$ and $T_{cc}^{+}\left(3875\right)$
• Substructure of Multiquark Hadrons (Snowmass 2021 White Paper)
• Unravelling Pentaquarks with Born--Oppenheimer effective theory
• Born-Oppenheimer Potentials for $SU(3)$ Gauge Theory
• Baryons, multi-hadron systems, and composite dark matter in non-relativistic QCD
• Narrow exotic hadrons in the heavy quark limit of QCD
• Effect of continuum states on the double-heavy hadron spectra
• Hybrid static potentials in SU(2) lattice gauge theory at short quark-antiquark separations
• Mass spectrum of the hidden-charm hybrid states via the QCD sum rules
• Hybrid to Quarkonia transitions
• QCD confronts heavy-flavor and exotic hadrons
• QCD static force in gradient flow
• Lattice spectroscopy with focus on exotics
• Doubly heavy baryons in Born-Oppenheimer EFT