149 research outputs found
Hydrodynamics of the Polyakov Line in SU Yang-Mills
We discuss a hydrodynamical description of the eigenvalues of the Polyakov
line at large but finite for Yang-Mills theory in even and odd space-time
dimensions. The hydro-static solutions for the eigenvalue densities are shown
to interpolate between a uniform distribution in the confined phase and a
localized distribution in the de-confined phase. The resulting critical
temperatures are in overall agreement with those measured on the lattice over a
broad range of , and are consistent with the string model results at
. The stochastic relaxation of the eigenvalues of the Polyakov line
out of equilibrium is captured by a hydrodynamical instanton. An estimate of
the probability of formation of a Z(N bubble using a piece-wise sound wave
is suggested.Comment: 5 pages, 2 figure
Hydrodynamics of the Chiral Dirac Spectrum
We derive a hydrodynamical description of the eigenvalues of the chiral Dirac
spectrum in the vacuum and in the large (volume) limit. The linearized
hydrodynamics supports sound waves. The stochastic relaxation of the
eigenvalues is captured by a hydrodynamical instanton configuration which
follows from a pertinent form of Euler equation. The relaxation from a phase of
localized eigenvalues and unbroken chiral symmetry to a phase of de-localized
eigenvalues and broken chiral symmetry occurs over a time set by the speed of
sound. We show that the time is with
the spectral density at zero virtuality and for the
three Dyson ensembles that characterize QCD with different quark
representations in the ergodic regime.Comment: 6 page
Causality constraints on TMD soft factors: the exponential regulator without cuts
We show that as a result of causality-constrained coordinate space
analyticity, the Drell-Yan-shape transverse-momentum dependent soft factor in
the exponential regulator allows below-threshold (Euclidean) parametric
representations without cuts, to all orders in perturbation theory. Moreover,
it is identical to another soft factor with natural interpretation as a
space-like form factor and this relation continues to hold for a larger class
of TMD soft factors that interpolate between three different rapidity
regulators: the off-light-cone regulator, the finite light-front length
regulator and the exponential regulator.Comment: 24 pages, 3 figures. Typos related to L^-, L^+ in certain
Wilson-lines are corrected and a new appendix B on path-connectedness of
certain regions is adde
Heavy Holographic Exotics: Tetraquarks as Efimov States
We provide a holographic description of non-strange multiquark exotics as
compact topological molecules by binding heavy-light mesons to a tunneling
configuration in D8-D that is homotopic to the vacuum state with fixed
Chern-Simons number. In the tunneling process, the heavy-light mesons transmute
to fermions. Their binding is generic and arises from a trade-off between the
dipole attraction induced by the Chern-Simons term and the U(1) fermionic
repulsion. In the heavy quark limit, the open-flavor tetraquark exotics and , emerge as bound Efimov states in a degenerate
multiplet with opposite intrinsic Chern-Simons numbers
. The hidden-flavor tetraquark exotics such as ,
and as compact topological molecules are
unbound. Other exotics are also discussed.Comment: 16 pages, 13 figure
Hydrodynamical Description of the QCD Dirac Spectrum at Finite Chemical Potential
We present a hydrodynamical description of the QCD Dirac spectrum at finite
chemical potential as an uncompressible droplet in the complex eigenvalue
space. For a large droplet, the fluctuation spectrum around the hydrostatic
solution is gapped by a longitudinal Coulomb plasmon, and exhibits a
frictionless odd viscosity. The stochastic relaxation time for the
restoration/breaking of chiral symmetry is set by twice the plasmon frequency.
The leading droplet size correction to the relaxation time is fixed by a
universal odd viscosity to density ratio for the
three Dyson ensembles .Comment: 5 page
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