Symmetries of hadrons after unbreaking the chiral symmetry

Abstract

We study hadron correlators upon artificial restoration of the spontaneously broken chiral symmetry. In a dynamical lattice simulation we remove the lowest lying eigenmodes of the Dirac operator from the valence quark propagators and study evolution of the hadron masses obtained. All mesons and baryons in our study, except for a pion, survive unbreaking the chiral symmetry and their exponential decay signals become essentially better. From the analysis of the observed spectroscopic patterns we conclude that confinement still persists while the chiral symmetry is restored. All hadrons fall into different chiral multiplets. The broken U(1)_A symmetry does not get restored upon unbreaking the chiral symmetry. We also observe signals of some higher symmetry that includes chiral symmetry as a subgroup. Finally, from comparison of the Δ- N splitting before and after unbreaking of the chiral symmetry we conclude that both the color-magnetic and the flavor-spin quark-quark interactions are of equal importance.

12 pages, 14 figures; final version

References in corpus (9)

• Chiral symmetry breaking and the Banks--Casher relation in lattice QCD with Wilson quarks
• Restoration of chiral and $U(1{)}_A$ symmetries in excited hadrons
• Local coherence and deflation of the low quark modes in lattice QCD
• Highly Excited Mesons, Linear Regge Trajectories and the Pattern of the Chiral Symmetry Realization
• Hadron Spectroscopy with Dynamical Chirally Improved Fermions
• Chirally symmetric but confining dense and cold matter
• Parity Doubling Among the Baryons
• Derivative sources in lattice spectroscopy of excited light-quark mesons
• Effective chiral restoration in the hadronic spectrum and QCD

Cited by in corpus (10)

• An effective model for the QCD phase transitions at finite baryon density
• Isoscalar mesons upon unbreaking of chiral symmetry
• SU(4) symmetry of the dynamical QCD string and genesis of hadron spectra
• Relation between Confinement and Chiral Symmetry Breaking in Temporally Odd-number Lattice QCD
• Overlap Quark Propagator in Coulomb Gauge QCD and the Interrelation of Confinement and Chiral Symmetry Breaking
• Baryon and chiral symmetry breaking in holographic QCD
• Selected Issues in Thermal Field Theory
• Proton Mass, Topology Change and Tensor Forces in Compressed Baryonic Matter
• Effective Chiral Symmetry Restoration for Heavy-Light Mesons
• Mesons upon low-lying Dirac mode exclusion