6,257 research outputs found
Mixing Angle of Hadrons in QCD: A New View
A new method for calculation of the mixing angle between the hadrons within
QCD sum rules is proposed. In this method, the mixing is expressed in terms of
quark and gluon degrees of freedom. As an application, the detailed calculation
of the mixing angle between heavy cascade baryons Xi_Q and Xi_Q', Q=c,~b is
presented and it is found that the mixing angle between Xi_b (Xi_c) and Xi_b'
(Xi_c') is given by theta_b = 6.4^\circ \pm 1.8 ^\circ (theta_c = 5.5^\circ \pm
1.8^\circ).Comment: 10 pages, 4 figures, 1 table, Changes in the text onl
Double-lepton polarizations in (B -> l^+ l^- gamma) decay
Double-lepton polarization asymmetries in the (B -> l^+ l^- gamma) decay are
calculated using the most general, model independent form of the effective
Hamiltonian including all possible forms of the interaction. The dependencies
of the asymmetries on new Wilson coefficients are investigated. The
detectability the averaged double-lepton polarization asymmetries at LHC is
also discussed.Comment: 20 pages, 7 PostScript figures, LaTeX formatte
Light vector meson octet-decuplet baryon vertices in QCD
The strong coupling constants between light vector mesons and octet-decuplet
baryons are calculated in framework of the light cone QCD sum rules, taking
into account SU(3) flavor symmetry breaking effects. It is shown that all
strong coupling constants can be represented in terms of a single universal
function. Size of the SU(3) symmetry breaking effects are estimated.Comment: 27 pages, 6 figures, LaTeX formatte
Vector meson dominance and radiative decays of heavy spin-3/2 baryons to heavy spin--1/2 baryons
Using the calculated values of the strong coupling constants of the heavy
sextet spin-3/2 baryons to sextet and antitriplet heavy spin-1/2 baryons with
light mesons within the light cone QCD sum rules method, and vector meson
dominance assumption, the radiative decay widths are calculated. These widths
are compared with the "direct" radiative decay widths predicted in the
framework of the light cone QCD sum rules.Comment: 8 pages, no figures, LaTeX formatte
Unitary Structure of the QCD Sum Rules and KYN and KY\Xi Couplings
New relations between QCD Borel sum rules for strong coupling constants of
K-mesons to baryons are derived. It is shown that starting from the sum rule
for the coupling constants and it
is straightforward to obtain corresponding sum rules for the , couplings, .Comment: 7 pages, 2 tables, International Workshop on Quantum
Chromodynamics:Theory and Experiment, QCD@Work-2005, Coversano(Bari, Italy),
16-20 June, 200
Magnetic Moments of Heavy Baryons in Light Cone QCD Sum Rules
The magnetic moments of heavy baryons containing a single charm or
bottom quark are calculated in the framework of light cone QCD sum rules
method. A comparison of our results with the predictions of the quark models is
presented.Comment: 26 Pages, 8 Figures and 1 Tabl
Electromagnetic form factors of the (rho) meson in light cone QCD sum rules
We investigate the electromagnetic form factors of the (rho) meson in light
cone QCD sum rules. We find that the ratio of the magnetic and charge form
factors is larger than two at all values of Q^2, (Q^2 >= 0.5 GeV^2). The values
of the individual form factors at fixed values of Q^2 predicted by the light
cone QCD sum rules are quite different compared to the results of other
approaches. These results can be checked in future, when more precise data on
(rho) meson form factors is available.Comment: 12 pages, 6 figures, LaTeX formatte
Scalar form factor of the nucleon and nucleon--scalar meson coupling constant in QCD
Scalar form factor of the nucleon is calculated in the framework of light
cone QCD sum rules, using the most general form of the baryon current. Using
the result on scalar form factor of the nucleon, the nucleon-scalar "sigma" and
"a_0" meson coupling constants are estimated. Our results on these couplings
are in good agreement with the prediction of the external field QCD sum rules
method.Comment: 20 pages, 12 figures, LaTeX formatte
Broadband probing magnetization dynamics of the coupled vortex state permalloy layers in nanopillars
Broadband magnetization response of coupled vortex state magnetic dots in
layered nanopillars was explored as a function of in-plane magnetic field and
interlayer separation. For dipolarly coupled circular Py(25 nm)/Cu(20 nm)/Py(25
nm) nanopillars of 600 nm diameter, a small in-plane field splits the
eigenfrequencies of azimuthal spin wave modes inducing an abrupt transition
between in-phase and out-of-phase kinds of the low-lying coupled spin wave
modes. The critical field for this splitting is determined by antiparallel
chiralities of the vortices in the layers. Qualitatively similar (although more
gradual) changes occur also in the exchange coupled Py(25 nm)/Cu(1 nm)/Py(25
nm) tri-layer nanopillars. These findings are in qualitative agreement with
micromagnetic dynamic simulations
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