Lattice QCD investigation of the structure of the $a_0(980)$ meson

Abstract

We investigate the quark content of the scalar meson $a_0(980)$ using lattice QCD. To this end we consider correlation functions of six different two- and four-quark interpolating fields. We evaluate all diagrams, including diagrams, where quarks propagate within a timeslice, e.g. with closed quark loops. We demonstrate that diagrams containing such closed quark loops have a drastic effect on the final results and, thus, may not be neglected. Our analysis shows that in addition to the expected spectrum of two-meson scattering states there is an additional energy level around the two-particle thresholds of $K+\bar{K}$ and $\eta +\pi$. This additional state, which is a candidate for the $a_0(980)$ meson, couples to a quark-antiquark as well as to a diquark-antidiquark interpolating field, indicating that it is a superposition of an ordinary $\bar{q}q$ and a tetraquark structure. The analysis is performed using AMIAS, a novel statistical method based on the sampling of all possible spectral decompositions of the considered correlation functions, as well as solving standard generalized eigenvalue problems.

11 pages, 10 figures

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Cited by in corpus (18)

• Semileptonic Decays of Charmed Mesons to Light Scalar Mesons
• Scalar mesons and the fragmented glueball
• Tetraquark interpolating fields in a lattice QCD investigation of the $D_{s0}^{\ast }(2317)$ meson
• Importance of meson-meson and of diquark-antidiquark creation operators for a $\bar{b}\bar{b}ud$ tetraquark
• Hadronic three-body D decays mediated by scalar resonances
• Isovector scalar $a_0(980)$ and $a_0(1450)$ resonances in the $B\to \psi (K\bar{K},\pi \eta )$ decays
• Revisiting the pion Regge trajectories
• $a_0(980)$-meson twist-2 distribution amplitude within the QCD sum rules and investigation of $D\to a_0(980)(\to \eta \pi )e^{+}{\nu }_e$
• The light scalars: four- vs. two-quark states in the complex energy plane from Bethe-Salpeter equations
• Observation of ${\Lambda }_c^{+}\to \Lambda a_0(980{)}^{+}$ and Evidence for $\Sigma (1380{)}^{+}$ in ${\Lambda }_c^{+}\to \Lambda {\pi }^{+}\eta$
• Probing $|V_{cs}|$ and lepton flavor universality through $D\to K_0^{\ast }(1430)\ell {\nu }_{\ell }$ decay
• Elastic Nucleon-Pion scattering amplitudes in the $\Delta$ channel at physical pion mass from Lattice QCD
• Including Tetraquark Operators in the Low-Lying Scalar Meson Sectors in Lattice QCD
• Study of the light scalar $a_0(980)$ through the decay $D^0\to a_0(980{)}^{-}{e}^{+}{\nu }_e$ with $a_0(980{)}^{-}\to \eta {\pi }^{-}$
• Searching for $a_0(980)$-meson parton distribution function
• Investigating the role of tetraquark operators in lattice QCD studies of the $a_0(980)$ and $\kappa$ resonances
• Observation of ${\Lambda }_c^{+}\to n{\pi }^{+}\eta$ and search for ${\Lambda }_c^{+}\to n{a}_0(980{)}^{+}$
• Transition form factors for $D/B$ to $a_0(980)$ from light-cone QCD sum rules