Continuum Goldstone spectrum of two-color QCD at finite density with staggered quarks

Abstract

We carry out lattice simulations of two-color QCD and spectroscopy at finite density with two flavors of rooted-staggered quarks and a diquark source term. As in a previous four-flavor study, for small values of the inverse gauge coupling we observe a Goldstone spectrum which reflects the symmetry-breaking pattern of a Gaussian symplectic chiral random-matrix ensemble (GSE) with Dyson index ${\beta }_D=4$, which corresponds to any-color QCD with adjoint quarks in the continuum instead of QC${}_2$D wih fundamental quarks. We show that this unphysical behavior occurs only inside of the bulk phase of $SU(2)$ gauge theory, where the density of $Z_2$ monopoles is high. Using an improved gauge action and a somewhat larger inverse coupling to suppress these monopoles, we demonstrate that the continuum Goldstone spectrum of two-color QCD, corresponding to a Gaussian orthogonal ensemble (GOE) with Dyson index ${\beta }_D=1$, is recovered also with rooted-staggered quarks once simulations are performed away from the bulk phase. We further demonstrate how this change of random-matrix ensemble is reflected in the distribution of eigenvalues of the Dirac operator. By computing the unfolded level spacings inside and outside of the bulk phase, we demonstrate that, starting with the low-lying eigenmodes which determine the infrared physics, the distribution of eigenmodes continuously changes from the GSE to the GOE one as monopoles are suppressed.

arXiv comment14 pages

References in corpus (41)

• QCD at finite isospin density
• Random Matrix Theory and Chiral Symmetry in QCD
• QCD-like Theories at Finite Baryon Density
• On two-color QCD with baryon chemical potential
• QCD phase diagram for nonzero isospin-asymmetry
• Numerical Study of Dense Adjoint Matter in Two Color QCD
• Symmetries and spectrum of SU(2) Lattice Gauge Theory at finite chemical potential
• BEC-BCS Crossover in the Nambu--Jona-Lasinio Model of QCD
• Two-colour QCD at non-zero quark-number density
• Deconfinement in dense 2-color QCD
• Quark-meson-diquark model for two-color QCD
• Fluctuations in the quark-meson model for QCD with isospin chemical potential
• Towards the phase diagram of dense two-color matter
• A Quarkyonic Phase in Dense Two Color Matter?
• Lattice QCD at non-zero isospin chemical potential
• Diquark Condensate in QCD with Two Colors at Next-to-Leading Order
• Study of the phase diagram of dense two-color QCD within lattice simulation
• Diquark Condensation at Nonzero Chemical Potential and Temperature
• Singular values of the Dirac operator in dense QCD-like theories
• Lattice QCD with 8 Light Quark Flavors
• Polyakov-Quark-Meson-Diquark Model for two-color QCD
• Breakdown of staggered fermions at nonzero chemical potential
• Nambu-Jona-Lasinio model description of weakly interacting Bose condensate and BEC-BCS crossover in dense QCD-like theories
• Chiral Lagrangian and spectral sum rules for dense two-color QCD
• Chiral random matrix theory for two-color QCD at high density
• Phase-diagram of two-color lattice QCD in the chiral limit
• Observation of deconfinement in a cold dense quark medium
• The phase diagram of a gauge theory with fermionic baryons
• The pseudo-Goldstone spectrum of 2-colour QCD at finite density
• Lattice Study of Dense Matter with Two Colors and Four Flavors
• Lattice study of static quark-antiquark interactions in dense quark matter
• SU(3) Lattice Gauge Theory in the Fundamental--Adjoint Plane and Scaling Along the Wilson Axis
• Bulk first-order phase transition in three-flavor lattice QCD with $O(a)$-improved Wilson fermion action at zero temperature
• On the chiral perturbation theory for two-flavor two-color QCD at finite chemical potential
• Hadron masses and baryonic scales in $G_2$-QCD at finite density
• Sarma phase in relativistic and non-relativistic systems
• Polyakov loops and spectral properties of the staggered Dirac operator
• Two-color QCD at high density
• Baryonic Matter Onset in Two-Color QCD with Heavy Quarks
• SO(3) vs. SU(2) Yang-Mills theory on the lattice: an investigation at non-zero temperature
• Generalised Wigner surmise for 2x2 random matrices

Cited by in corpus (19)

• Dense 2-color QCD towards continuum and chiral limits
• Lattice study of thermodynamic properties of dense QC${}_2$D
• Electric conductivity in finite-density SU(2) lattice gauge theory with dynamical fermions
• Dense two-color QCD from Dyson-Schwinger equations
• Effects of Dense Quark Matter on Gluon Propagators in Lattice QC${}_2$D
• Thermal quarks and gluon propagators in two-color dense QCD
• Numerical Study of the Chiral Separation Effect in Two-Color QCD at Finite Density
• Probing the hadron mass spectrum in dense two-color QCD with the linear sigma model
• Fate of the topological susceptibility in two-color dense QCD
• Entropy and Temperature in finite isolated quantum systems
• Sound velocity peak induced by the chiral partner in dense two-color QCD
• Study of two color QCD on large lattices
• Fluctuation-induced higher-derivative couplings and infrared dynamics of the Quark-Meson-Diquark Model
• When cold, dense quarks in 1+1 and 3+1 dimensions are not a Fermi liquid
• QCD Anderson transition with overlap valence quarks on a twisted-mass sea
• Chiral effective model of cold and dense two-color QCD: The linear sigma model approach
• The $\theta$-angle and axion physics of two-color QCD at fixed baryon charge. Part I
• Relative scale setting for two-color QCD with Nf=2 Wilson fermions
• Speed of sound peak in two-color dense QCD: confronting effective models with lattice data