Chiral effective theory of diquarks and the U_A(1) anomaly

Abstract

The diquark is a strongly correlated quark pair that plays an important role in hadrons and hadronic matter. In order to treat the diquak as a building block of hadrons, we formulate an effective theory of diquark fields with $SU(3{)}_R\times SU(3{)}_L$ chiral symmetry. We concentrate on the scalar ($0^{+}$) and pseudoscalar ($0^{-}$) diquarks and construct a linear-sigma-model Lagrangian. It is found that the effective Lagrangian contains a new type of chirally symmetric meson-diquark-diquark coupling that breaks axial $U_A(1)$ symmetry. We discuss consequences of the $U_A(1)$ anomaly term to the diquark masses as well as to the singly heavy baryon spectrum, which is directly related to the diquark spectrum. We find an inverse mass ordering between strange and nonstrange diquarks. The parameters of the effective theory can be determined by the help of lattice QCD calculations of diquarks and also from the mass spectrum of the singly heavy baryons. We determine the strength of the $U_A(1)$ anomaly term, which is found to give a significant portion of the diquark masses.

10 pages, 1 figure

References in corpus (10)

• Pentaquark and Tetraquark states
• Charmed bottom baryon spectroscopy from lattice QCD
• New Critical Point Induced by the Axial Anomaly in Dense QCD
• Evidence for diquarks in lattice QCD
• Phase structure, collective modes, and the axial anomaly in dense QCD
• Diquark correlations in baryons on the lattice with overlap quarks
• Single heavy baryons with chiral partner structure in a three-flavor chiral model
• Diquark effects in light baryon correlators from lattice QCD
• Chiral Properties of Baryon Interpolating Fields
• Excitation energy spectra of the Lambda_c and Lambda_b baryons in a finite-size diquark model

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• Probing the hadron mass spectrum in dense two-color QCD with the linear sigma model
• Novel pentaquark picture for singly heavy baryons from chiral symmetry
• Suppression of decay widths in singly heavy baryons induced by the $U_A(1)$ anomaly
• Decays of Roper-like singly heavy baryons in a chiral model
• Strong decays of singly heavy baryons from a chiral effective theory of diquarks
• Axial anomaly effect to the chiral-partner structure of diquarks at high temperature
• Hunting for the prospective $T_{cc}$ family based on the diquark-antidiquark configuration
• Chiral effective model of cold and dense two-color QCD: The linear sigma model approach
• Axial anomaly effect on three-quark and five-quark singly heavy baryons
• Fate of ${\Sigma }_c$, ${\Xi }_c^{\prime }$ and ${\Omega }_c$ baryons at high temperature with chiral restoration
• Enhancement of axial anomaly effects in hot two-color QCD: FRG approach in the linear sigma model
• The $Z_{cs}$ states and the mixture of hadronic molecule and diquark-anti-diquark components within effective field theory
• Chiral effective theory of scalar and vector diquarks revisited
• Roles of $U(1)$ axial anomaly effects in cold and dense two-color QCD with $2+2$ flavors