Isoscalar mesons upon unbreaking of chiral symmetry

Abstract

In a dynamical lattice simulation with the overlap Dirac operator and $N_f=2$ mass degenerate quarks we study all possible $J=0$ and $J=1$ correlators upon exclusion of the low lying "quasi-zero" modes from the valence quark propagators. After subtraction of a small amount of such Dirac eigenmodes all disconnected contributions vanish and all possible point-to-point $J=0$ correlators with different quantum numbers become identical, signaling a restoration of the $SU(2{)}_L\times SU(2{)}_R\times U(1{)}_A$. The original ground state of the $\pi$ meson does not survive this truncation, however. In contrast, in the $I=0$ and $I=1$ channels for the $J=1$ correlators the ground states have a very clean exponential decay. All possible chiral multiplets for the $J=1$ mesons become degenerate, indicating a restoration of an $SU(4)$ symmetry of the dynamical QCD-like string.

10 pages, 13 figures

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• Two-flavor QCD simulation with exact chiral symmetry
• Symmetries of hadrons after unbreaking the chiral symmetry
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Cited by in corpus (6)

• Symmetries of spatial meson correlators in high temperature QCD
• SU(4) symmetry of the dynamical QCD string and genesis of hadron spectra
• Fluctuations of conserved charges, chiral spin symmetry and deconfinement in an SU(2)_color subgroup of SU(3)_color above T_c
• Chiral-spin symmetry emergence in baryons and eigenmodes of the Dirac operator
• Mesons upon low-lying Dirac mode exclusion
• $SU(4)$-Ward identities for QCD with restored chiral symmetry