713 research outputs found
Holographic Hadro-Quarkonium
We consider the recently suggested model for some resonances near the open
charm threshold as bound states of charmonium inside excited light mesons. It
is argued in the soft-wall holographic model of QCD that such states of heavy
quarkonium necessarily exist at sufficiently large spin of the light meson. The
bound state is provided by the dilaton exchange through the 5D bulk. We also
argue that the decay of such bound systems into mesons with open heavy flavors
due to splitting of the heavy quarkonium can be treated as semiclassical
tunneling and is suppressed. This behavior is in agreement with the known
relative suppression of the decay of the discussed charmonium-like resonances
into channels with D mesons.Comment: 11 pages, 1 figur
Spontaneous Symmetry Breaking and Phase Coexistence in Two-Color Networks
We have considered an equilibrium ensemble of large Erd\H{o}s-Renyi
topological random networks with fixed vertex degree and two types of vertices,
black and white, prepared randomly with the bond connection probability, .
The network energy is a sum of all unicolor triples (either black or white),
weighted with chemical potential of triples, . Minimizing the system
energy, we see for some positive formation of two predominantly unicolor
clusters, linked by a "string" of black-white bonds. We have
demonstrated that the system exhibits critical behavior manifested in emergence
of a wide plateau on the -curve, which is relevant to a spinodal
decomposition in 1st order phase transitions. In terms of a string theory, the
plateau formation can be interpreted as an entanglement between baby-universes
in 2D gravity. We have conjectured that observed classical phenomenon can be
considered as a toy model for the chiral condensate formation in quantum
chromodynamics.Comment: 9 pages, 4 figure
Dualities in integrable systems and N=2 theories
We discuss dualities of the integrable dynamics behind the exact solution to
the N=2 SUSY YM theory. It is shown that T duality in the string theory is
related to the separation of variables procedure in dynamical system. We argue
that there are analogues of S duality as well as 3d mirror symmetry in the
many-body systems of Hitchin type governing low-energy effective actions.Comment: 16 pages, Latex, Talk given at QFTHEP-99, Moscow, May 27-June
Anomalous Chiral Fermi Surface
We provide a geometrical argument for the emergence of a Wess-Zumino-Witten
(WZW) term for a Fermi surface threaded by a Berry curvature. In the presence
of external fields, the gauged WZW term yields a chiral (triangle) anomaly for
the fermionic current at the edge of the Fermi surface. Fermion number is
conserved though since the Berry curvatures occur always in pairs with opposite
(monopole) charge. The anomalous vector and axial currents for a a fermionic
fluid at low temperature threaded by pairs of Berry curvatures are discussed.
The leading temperature correction to the chiral vortical effect in a slowly
rotating Fermi surface threaded by a Berry curvature maybe tied to the
gravitational anomaly.Comment: 4 pages; version to appear in PR
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