861 research outputs found
The magnetic moments of 'Lambda_b' and 'Lambda_c' baryons in light cone QCD sum rules
Using the most general form of the interpolating currents of heavy baryons,
the magnetic moments of heavy baryons "Lambda_Q (Q=b,c)" are calculated in
framework of the light cone QCD sum rules. A comparison of our results on
magnetic moments with the existing theoretical results calculated in various
other frameworks are presented.Comment: 14 pp, 6 figures (postscript formatted), LaTex formatte
Calculation of Chirality Violating Proton Structure Function h(x) in QCD
The twist-two chirality violating proton structure function
measurable in the polarized Drell-Yan process is calculated by means of QCD sum
rules at intermediate , and .Comment: 12 pages + 6 figures , LaTeX, preprint LMU-01-94. a few additions to
the text; the figures have been added as uuencoded fil
On the Strength Calculation of the Rotating parts
AbstractThe existing solutions of differential equations of equilibrium of an infinitesimal element of the rotating parts of an isotropic elastic solid known as the Navier equilibrium equations are considered. Examples of the flat disk calculation by solving the differential equilibrium equations by the sweep method and the finite element method in the modern program “Autodesk Simulation Multiphysics” are represented; paradoxical changes of radial and hoop stresses are revealed. An original method of derivation formulas based only on the principle of d’Alembert to calculate radial and hoop stresses in parts that operate under centrifugal (inertial) forces is proposed. The solution for rotating disks of any profile that corrects unnatural classical solutions is obtained. Analysis of the obtained new formulas for calculating stresses shows that it is necessary to reject the concept of “equal-strength disk” because of the inability to provide the equality of the hoop and radial stress in all sections of the disk. A new method of the optimum strength disk profile calculation, which requires a restriction of outer radius disk, is suggested. In designing of optimum strength rotating parts is recommended to limit outer disk radius of where [σ] − the allowable stress, ρ − density of the disk material; ω − angular velocity of disk rotation
Phenomenology of the Heavy Flavored spin 3/2 Baryons in Light Cone QCD
Motivated by the results of the recent experimental discoveries for charm and
bottom baryons, the masses and magnetic moments of the heavy baryons with
containing a single heavy quark are studied within light cone QCD
sum rules method. Our results on the masses of heavy baryons are in good
agreement with predictions of other approaches, as well as with the existing
experimental data.Comment: 12 Pages, 18 Figures and 3 Tables. Based on: arXiv:0807.3481v2
[hep-ph](Nucl.Phys.B808:137-154,2009). To be Published in the Proceeding of
the International Conference on New Trends in High Energy Physics, 27 Sept.-4
Oct. 2008, Yalta, Crimea, Ukrain
g_{rho sigma gamma} coupling constant in light cone QCD
The coupling constant g_{rho sigma gamma} is determined from light cone QCD
sum rules. A comparison of our result with the ones existing in literature is
presented.Comment: 7 pp, 2 figures (postscript formatted), LaTex formatte
Twist-3 Distribute Amplitude of the Pion in QCD Sum Rules
We apply the background field method to calculate the moments of the pion
two-particles twist-3 distribution amplitude (DA) in QCD sum
rules. In this paper,we do not use the equation of motion for the quarks inside
the pion since they are not on shell and introduce a new parameter to
be determined. We get the parameter in this approach. If
assuming the expansion of in the series in Gegenbauer polynomials
, one can obtain its approximate expression which can be
determined by its first few moments.Comment: 12 pages, 3 figure
The (Sigma_Q-Lambda_Q) transition magnetic moments in light cone QCD sum rules
Using the general form of (Sigma_Q) and (Lambda_Q) (Q=b or c) currents,
(Sigma_Q-Lambda_Q) transition magnetic moments are calculated in framework of
the light cone QCD sum rules method. In this approach nonperturbative effects
are described by the photon wave functions and only two-particle photon wave
functions are taken into account. Our predictions on transition magnetic
moments are (mu_{Sigma_c Lambda_c} = - (1.5 pm 0.4) mu_N) and (mu_{Sigma_b
Lambda_b} = - (1.6 pm 0.4) mu_N). A comparison of our results with the ones
existing in the literature is given.Comment: 15 pp, 6 figures (postscript formatted), LaTex formatte
Neutron EDM from Electric and Chromoelectric Dipole Moments of Quarks
Using QCD sum rules, we calculate the electric dipole moment of the neutron
d_n induced by all CP violating operators up to dimension five. We find that
the chromoelectric dipole moments of quarks \tilde d_i, including that of the
strange quark, provide significant contributions comparable in magnitude to
those induced by the quark electric dipole moments d_i. When the theta term is
removed via the Peccei-Quinn symmetry, the strange quark contribution is also
suppressed and d_n =(1\pm 0.5)[1.1e(\tilde d_d + 0.5\tilde
d_u)+1.4(d_d-0.25d_u)].Comment: 4 pages, revtex, v2: missing overall factor of two reinstate
Phase of the Wilson Line at High Temperature in the Standard Model
We compute the effective potential for the phase of the Wilson line at high
temperature in the standard model to one loop order. Besides the trivial vacua,
there are metastable states in the direction of hypercharge. Assuming
that the universe starts out in such a metastable state at the Planck scale, it
easily persists to the time of the electroweak phase transition, which then
proceeds by an unusual mechanism. All remnants of the metastable state
evaporate about the time of the phase transition.Comment: 4 pages in ReVTeX plus 1 figure; Columbia Univ. preprint CU-TP-63
Radiative and decays in light cone QCD sum rules
The radiative decays are investigated
in the framework of light cone QCD sum rules. The transition amplitude and
decay rates are estimated.It is shown that our results on branching ratios of D
meson decays are in good agreement with the existing experimental data.Comment: 13 pages, Latex, 3 figure
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