A continuous one-parameter family of holographic geometries interpolates between confining and deconfined phases, with string tension and chiral condensate vanishing smoothly at the black hole endpoint.
Unsal,Magnetic bion condensation: A New mechanism of confinement and mass gap in four dimensions, Phys
4 Pith papers cite this work. Polarity classification is still indexing.
abstract
In recent work, we derived the long-distance confining dynamics of certain QCD-like gauge theories formulated on small $S^1 \times \R^3$ based on symmetries, an index theorem, and Abelian duality. Here, we give the microscopic derivation. The solution reveals a new mechanism of confinement in QCD(adj) in the regime where we have control over both perturbative and nonperturbative aspects. In particular, consider SU(2) QCD(adj) theory with $1 \leq n_f \leq 4$ Majorana fermions, a theory which undergoes gauge symmetry breaking at small $S^1$. If the magnetic charge of the BPS monopole is normalized to unity, we show that confinement occurs due to condensation of objects with magnetic charge 2, not 1. Because of index theorems, we know that such an object cannot be a two identical monopole configuration. Its net topological charge must vanish, and hence it must be topologically indistinguishable from the perturbative vacuum. We construct such non-self-dual topological excitations, the magnetically charged, topologically null molecules of a BPS monopole and ${\bar{\rm KK}}$ antimonopole, which we refer to as magnetic bions. An immediate puzzle with this proposal is the apparent Coulomb repulsion between the BPS-${\bar{\rm KK}}$ pair. An attraction which overcomes the Coulomb repulsion between the two is induced by $2n_f$-fermion exchange. Bion condensation is also the mechanism of confinement in $\N=1$ SYM on the same four-manifold. The SU(N) generalization hints a possible hidden integrability behind nonsupersymmetric QCD of affine Toda type, and allows us to analytically compute the mass gap in the gauge sector. We currently do not know the extension to $\R^4$.
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The local moduli space of self-dual fractional instantons (Q = r/N) on a twisted four-torus is the Higgs branch of an N=2 supersymmetric theory, obtained via wrapped intersecting D-brane configurations.
Simulations of a partially reduced twisted Eguchi-Kawai model with one adjoint Dirac fermion show the Polyakov loop remains near zero for periodic boundary conditions as the compactified circle shrinks, supporting adiabatic continuity of the confined phase.
Extended lattice simulations yield continuum-limit anomalous dimensions γ* = 0.170(6) for Nf=1 and γ* = 0.291(9) for Nf=2 adjoint SU(2), with chiral perturbation theory ruling out spontaneous chiral symmetry breaking.
citing papers explorer
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Confinement and chiral symmetry breaking in holography: a smooth switch-off
A continuous one-parameter family of holographic geometries interpolates between confining and deconfined phases, with string tension and chiral condensate vanishing smoothly at the black hole endpoint.
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D-branes and fractional instantons on a twisted four torus: the moduli space as an N=2 supersymmetric Higgs branch
The local moduli space of self-dual fractional instantons (Q = r/N) on a twisted four-torus is the Higgs branch of an N=2 supersymmetric theory, obtained via wrapped intersecting D-brane configurations.
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Adiabatic continuity in a partially reduced twisted Eguchi-Kawai model with one adjoint Dirac fermion
Simulations of a partially reduced twisted Eguchi-Kawai model with one adjoint Dirac fermion show the Polyakov loop remains near zero for periodic boundary conditions as the compactified circle shrinks, supporting adiabatic continuity of the confined phase.
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SU(2) gauge theory with one and two adjoint fermions towards the continuum limit
Extended lattice simulations yield continuum-limit anomalous dimensions γ* = 0.170(6) for Nf=1 and γ* = 0.291(9) for Nf=2 adjoint SU(2), with chiral perturbation theory ruling out spontaneous chiral symmetry breaking.