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Related papers: Nucleon QCD sum rules in instanton vacuum

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We calculate the electromagnetic pion form factor at intermediate space-like momentum transfer from the QCD sum rule for the correlation function of two {\it pseudoscalar } interpolating fields and the electromagnetic current. This…

High Energy Physics - Phenomenology · Physics 2009-10-28 Hilmar Forkel , Marina Nielsen

We investigate the contribution of instantons to the eigenvalue spectrum of the Dirac operator in quenched QCD. The instanton configurations that we use have been derived, elsewhere, from cooled SU(3) lattice gauge fields and, for…

High Energy Physics - Lattice · Physics 2016-08-25 U. Sharan , M. Teper

We perform a mutual analysis of the topological and chiral vacuum structure of four-dimensional QCD on the lattice at finite temperature. We demonstrate that at the places where instantons are present, amplified production of quark…

High Energy Physics - Lattice · Physics 2009-10-30 Markus Feurstein , Harald Markum , Stefan Thurner

The light scalar nonets are studied using the QCD sum rules for the tetraquark operators. The operator product expansion for the correlators is calculated up to dimension 12 and this enables us to perform analyses retaining sufficient…

High Energy Physics - Phenomenology · Physics 2008-11-26 Toru Kojo , Daisuke Jido

Using the framework of QCD sum rules we predict the twist-3 contribution to the second moment of the polarized nucleon structure function $g_2(x)$. As the relevant local operator depends explicitely on the gluon field, we employ a recently…

High Energy Physics - Phenomenology · Physics 2011-08-11 E. Stein , P. Gornicki , L. Mankiewicz , A. Schaefer , W. Greiner

Standard QCD sum-rule analyses of the nucleon mass give results that are inconsistent with chiral perturbation theory due to an overly simple continuum ansatz on the phenomenological side of the sum rule. We show that a careful treatment of…

High Energy Physics - Phenomenology · Physics 2009-10-28 Su Houng Lee , Seungho Choe , Thomas D. Cohen , David K. Griegel

We use the method of QCD sum rules in the presence of an external pion field to investigate isospin symmetry breakings in pion-nucleon couplings. Possible manifestations of such isospin symmetry breaking are examined in the context of…

Nuclear Theory · Physics 2009-09-25 W-Y. P. Hwang , Ze-sen Yang , Y. S. Zhong , Z. N. Zhou , Shi-lin Zhu

The QCD sum rule approach to the in-medium behavior of hadrons is discussed for omega meson, nucleon and D meson. Emphasis is devoted to the impact of four-quark condensates and to order parameters of spontaneous symmetry breaking.

High Energy Physics - Phenomenology · Physics 2008-11-26 R. Thomas , T. Hilger , B. Kampfer

We compute the nucleon matrix elements of QCD operators of twist 3 and 4 in the instanton vacuum. We consider the operators determining 1/Q^2-power corrections to the Bjorken, Ellis-Jaffe and Gross-Llewellyn-Smith sum rules. The nucleon is…

High Energy Physics - Phenomenology · Physics 2009-10-30 J. Balla , M. V. Polyakov , C. Weiss

Based on the diquark configuration, we construct the diquark-antidiquark interpolating tetraquark currents with $J^{PC}=1^{-\pm}$ and $1^{+\pm}$, which can couple to the scalar and pseudoscalar tetraquark states respectively, since they are…

High Energy Physics - Phenomenology · Physics 2018-06-25 Zun-Yan Di , Zhi-Gang Wang

Using the Local Composite Operator formalism, we analytically study the dimension two gluon condensate in the presence of instantons. We first use the dilute gas approximation and partially solve the infrared problem of instanton physics.…

High Energy Physics - Theory · Physics 2011-04-01 David Vercauteren , Henri Verschelde

We review our current understanding of instanton effects in the large N_c limit of QCD. We argue that the instanton liquid can have a smooth large N_c limit which is in agreement with scaling relations derived from Feynman diagrams. We also…

High Energy Physics - Phenomenology · Physics 2017-08-23 Thomas Schaefer

QCD sum rules for D and B mesons embedded in cold nuclear matter are evaluated. We quantify the mass splitting of D - D-bar and B - B-bar mesons as a function of the nuclear matter density; extrapolated to saturation density it is in the…

Nuclear Theory · Physics 2009-09-29 T. Hilger , R. Thomas , B. Kampfer

We discuss a calculation of large-Nc masses of light scalar mesons from the QCD sum rules. Two methods based on the use of linear radial Regge trajectories are presented. We put a special emphasis on the appearance of pole near 0.5 GeV in…

High Energy Physics - Phenomenology · Physics 2018-05-30 S. S. Afonin , T. D. Solomko

An introduction to the method of QCD sum rules is given for those who want to learn how to use this method. Furthermore, we discuss various applications of sum rules, from the determination of quark masses to the calculation of hadronic…

High Energy Physics - Phenomenology · Physics 2016-11-23 Pietro Colangelo , Alexander Khodjamirian

The QCD sum rules in the large-$N_c$ limit for the light non-strange vector, axial and scalar mesons are considered assuming a string-like linear spectrum for the radially excited states. We propose a improved method for combined analysis…

High Energy Physics - Phenomenology · Physics 2016-12-13 S. S. Afonin , T. D. Solomko

The behavior of the action of the instantons describing vacuum decay in a de Sitter is investigated. For a near-to-limit instanton (a Coleman-de Luccia instanton close to some Hawking-Moss instanton) we find approximate formulas for the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 V. Balek , M. Demetrian

We suggest a constrained instanton (CI) solution in the physical QCD vacuum which is described by large-scale vacuum field fluctuations. This solution decays exponentially at large distances. It is stable only if the interaction of the…

High Energy Physics - Phenomenology · Physics 2011-09-13 A. E. Dorokhov , S. V. Esaibegyan , A. E. Maximov , S. V. Mikhailov

Numerical and anaytical studies of the instanton liquid model have allowed the determination of many hadronic parameters during the last 13 years. Most part of this thesis is devoted to the extension of the analytical methods. The meson…

High Energy Physics - Phenomenology · Physics 2007-05-23 Marcus Hutter

QCD sum rules are overviewed with an emphasize on the practical applications of this method to the physics of light and heavy hadrons.

High Energy Physics - Phenomenology · Physics 2017-08-23 Alexander Khodjamirian