Diquark properties from full QCD lattice simulations

Abstract

We study diquarks on the lattice in the background of a static quark, in a gauge-invariant formalism with quark masses down to almost physical $m_{\pi }$. We determine mass differences between diquark channels as well as diquark-quark mass differences. The lightest and next-to-lightest diquarks have "good" scalar, ${\bar{3}}_F$, ${\bar{3}}_c$, $J^P=0^{+}$, and "bad" axial vector, $6_F$, ${\bar{3}}_c$, $J^P=1^{+}$, quantum numbers, and a bad-good mass difference for $ud$ flavors, $198(4)\mathrm{MeV}$, in excellent agreement with phenomenological determinations. Quark-quark attraction is found only in the "good" diquark channel. We extract a corresponding diquark size of $\sim 0.6\mathrm{fm}$ and perform a first exploration of the "good" diquark shape, which is shown to be spherical. Our results provide quantitative support for modeling the low-lying baryon spectrum using good light diquark effective degrees of freedom.

20 pages, 8 figures, 2 tables, published version

References in corpus (14)

• Exotics: Heavy Pentaquarks and Tetraquarks
• Observation of an exotic narrow doubly charmed tetraquark
• Spectroscopy and Regge trajectories of heavy baryons in the relativistic quark-diquark picture
• Discovery of doubly-charmed Xi_{cc} baryon implies a stable (b b ubar dbar) tetraquark
• Heavy-quark symmetry implies stable heavy tetraquark mesons $Q_i{Q}_j{\bar{q}}_k{\bar{q}}_l$
• Lattice QCD investigation of a doubly-bottom $\bar{b}\bar{b}ud$ tetraquark with quantum numbers $I(J^P)=0(1^{+})$
• Evidence for diquarks in lattice QCD
• Masses of ground and excited-state hadrons
• Including heavy spin effects in the prediction of a $\bar{b}\bar{b}ud$ tetraquark with lattice QCD potentials
• On light baryons and their excitations
• Stability of tetrons
• Diquark correlations in baryons on the lattice with overlap quarks
• Fourier Accelerated Conjugate Gradient Lattice Gauge Fixing
• Heavy-Baryon Spectroscopy from Lattice QCD

Cited by in corpus (14)

• Signature of a doubly charm tetraquark pole in $D{D}^{\ast }$ scattering on the lattice
• The doubly charmed strange tetraquark
• Doubly charm tetraquark channel with isospin $1$ from lattice QCD
• The nature of ${\chi }_{c1}\left(3872\right)$ and $T_{cc}^{+}\left(3875\right)$
• Hidden-flavor pentaquarks
• Substructure of Multiquark Hadrons (Snowmass 2021 White Paper)
• $bb\bar{u}\bar{d}$ and $bs\bar{u}\bar{d}$ tetraquarks from lattice QCD using two-meson and diquark-antidiquark variational basis
• Strong decays of singly heavy baryons from a chiral effective theory of diquarks
• Lattice study of $cc\bar{u}\bar{s}$ tetraquark channel in $D^{(\ast )}{D}_s^{(\ast )}$ scattering
• Proton image and momentum distributions from light-front dynamics
• Chiral effective model of cold and dense two-color QCD: The linear sigma model approach
• Exotic Heavy Hadrons
• Chiral effective theory of scalar and vector diquarks revisited
• The chiral limit of a fermion-scalar $(1/2{)}^{+}$ system in covariant gauges