32 research outputs found
The open XXZ and associated models at q root of unity
The generalized open XXZ model at root of unity is considered. We review
how associated models, such as the harmonic oscillator, and the lattice
sine-Gordon and Liouville models are obtained. Explicit expressions of the
local Hamiltonian of the spin XXZ spin chain coupled to dynamical
degrees of freedom at the one end of the chain are provided. Furthermore, the
boundary non-local charges are given for the lattice sine Gordon model and the
harmonic oscillator with open boundaries. We then identify the spectrum and
the corresponding Bethe states, of the XXZ and the q harmonic oscillator in the
cyclic representation with special non diagonal boundary conditions. Moreover,
the spectrum and Bethe states of the lattice versions of the sine-Gordon and
Liouville models with open diagonal boundaries is examined. The role of the
conserved quantities (boundary non-local charges) in the derivation of the
spectrum is also discussed.Comment: 31 pages, LATEX, minor typos correcte
Gold-plated Mode of CP-Violation in Decays of B_c Meson from QCD Sum Rules
The model-independent method based on the triangle ideology is implemented to
extract the CKM-matrix angle gamma in the decays of doubly heavy long-lived
meson B_c. We analyze a color structure of diagrams and conditions to
reconstruct two reference-triangles by tagging the flavor and CP eigenstates of
D^0 meson in the fixed exclusive channels. The characteristic branching ratios
are evaluated in the framework of QCD sum rules.Comment: 11 pages, RevTeX4 file, 4 eps-figure
Doubly heavy baryons Omega_QQ' vs. Xi_QQ' in sum rules of NRQCD
In the framework of two-point sum rules of NRQCD, the masses and couplings of
doubly heavy baryons to the corresponding quark currents are evaluated with
account of coulomb-like corrections in the system of doubly heavy diquark as
well as the contribution of nonperturbative terms determined by the quark,
gluon, mixed condensates and the product of gluon and quark condensates. The
introduction of nonzero light quark mass destroys the factorization of baryon
and diquark correlators even at the perturbative level and provides the better
convergency of sum rules. We estimate the difference M_Omega - M_Xi = 100+/- 10
MeV. The ratio of baryonic constants |Z_Omega|^2/|Z_Xi|^2 is equal to 1.3+/-0.2
indicating the violation of SU(3) flavor symmetry for the doubly heavy baryons.Comment: 18 pages, ReVTeX file, 7 eps-figures, references adde