551 research outputs found
Chiral doublings of heavy-light hadrons: New charmed mesons discovered by BABAR,CLEO and BELLE
We remind the chiral doubling scenario [1,2] for hadrons built of heavy and
light quarks. Then we recall arguments why new states
D_s(2317),D_s(2460),D_0(2308) and D_1^'(2427) should be viewed as chiral
partners of D_s,D_s^*,D and D^*,respectively. We summarize with the list of
predictions based on chiral doubling scenario for other heavy-light hadrons.Comment: Talk at Hadron'03, Aschaffenburg, Germany, August 31st - September
6th, 2003. (5 pages, 1 figure
Probing non-orthogonality of eigenvectors in non-Hermitian matrix models: diagrammatic approach
Using large arguments, we propose a scheme for calculating the two-point
eigenvector correlation function for non-normal random matrices in the large
limit. The setting generalizes the quaternionic extension of free
probability to two-point functions. In the particular case of biunitarily
invariant random matrices, we obtain a simple, general expression for the
two-point eigenvector correlation function, which can be viewed as a further
generalization of the single ring theorem. This construction has some striking
similarities to the freeness of the second kind known for the Hermitian
ensembles in large . On the basis of several solved examples, we conjecture
two kinds of microscopic universality of the eigenvectors - one in the bulk,
and one at the rim. The form of the conjectured bulk universality agrees with
the scaling limit found by Chalker and Mehlig [JT Chalker, B Mehlig, PRL,
\textbf{81}, 3367 (1998)] in the case of the complex Ginibre ensemble.Comment: 20 pages + 4 pages of references, 12 figs; v2: typos corrected, refs
added; v3: more explanator
Spectra of large time-lagged correlation matrices from Random Matrix Theory
We analyze the spectral properties of large, time-lagged correlation matrices
using the tools of random matrix theory. We compare predictions of the
one-dimensional spectra, based on approaches already proposed in the
literature. Employing the methods of free random variables and diagrammatic
techniques, we solve a general random matrix problem, namely the spectrum of a
matrix , where is an Gaussian random
matrix and is \textit{any} , not necessarily symmetric
(Hermitian) matrix. As a particular application, we present the spectral
features of the large lagged correlation matrices as a function of the depth of
the time-lag. We also analyze the properties of left and right eigenvector
correlations for the time-lagged matrices. We positively verify our results by
the numerical simulations.Comment: 44 pages, 11 figures; v2 typos corrected, final versio
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
Chiral Random Matrix Model at Finite Chemical Potential: Characteristic Determinant and Edge Universality
We derive an exact formula for the stochastic evolution of the characteristic
determinant of a class of deformed Wishart matrices following from a chiral
random matrix model of QCD at finite chemical potential. In the WKB
approximation, the characteristic determinant describes a sharp droplet of
eigenvalues that deforms and expands at large stochastic times. Beyond the WKB
limit, the edges of the droplet are fuzzy and described by universal edge
functions. At the chiral point, the characteristic determinant in the
microscopic limit is universal. Remarkably, the physical chiral condensate at
finite chemical potential may be extracted from current and quenched lattice
Dirac spectra using the universal edge scaling laws, without having to solve
the QCD sign problem.Comment: 16 pages, 4 figure
Disorder in the Sachdev-Yee-Kitaev Model
We give qualitative arguments for the mesoscopic nature of the
Sachdev-Yee-Kitaev (SYK) model in the holographic regime with with
Majorana particles coupled by antisymmetric and random interactions of
range . Using a stochastic deformation of the SYK model, we show that its
characteristic determinant obeys a viscid Burgers equation with a small
spectral viscosity in the opposite regime with , in leading order. The
stochastic evolution of the SYK model can be mapped onto that of random matrix
theory, with universal Airy oscillations at the edges. A spectral
hydrodynamical estimate for the relaxation of the collective modes is made.Comment: 7 pages, 1 figur
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