English
Related papers

Related papers: Vacuum QCD and new information on nucleon structur…

200 papers

The contribution of the quark-quark and quark-gluon interaction induced by instantons to the valence quark and proton spin-dependent structure functions $g_1(x,Q^2)$ is estimated within the instanton liquid model for QCD vacuum. It is…

High Energy Physics - Phenomenology · Physics 2009-10-30 N. I. Kochelev

The instanton contribution to the quark distribution functions in the nucleon is estimated. It is shown, that taking into account the instanton induced interaction between quarks allows to explain the anomalous violation of the Ellis-Jaffe…

High Energy Physics - Phenomenology · Physics 2007-05-23 N. I. Kochelev

It is shown, that specific properties of the instanton induced interaction between quarks leads to the anomalous violation of the OZI-rule in the $N\bar N\to \Phi\Phi$, $N\bar N\to \Phi\gamma$ reactions. In the framework of instanton model…

High Energy Physics - Phenomenology · Physics 2011-04-15 N. I. Kochelev

We study isospin breaking instanton corrections to the operator product expansion of the nucleon correlation functions. After a comparison with quark model calculations based on the 't Hooft interaction, we examine the role of instantons in…

High Energy Physics - Phenomenology · Physics 2014-11-17 Hilmar Forkel , Marina Nielsen

It is shown that specific spin-flavour properties of the nonperturbative interaction between quarks induced by instantons allow us to explain the peculiarities of the OZI rule violation in $N \bar N$ annihilation. New experiments to test…

High Energy Physics - Phenomenology · Physics 2016-09-01 N. I. Kochelev

We construct improved QCD sum rules for the nucleon magnetic moments by implementing direct-instanton contributions to the operator product expansion of the nucleon correlator in a magnetic background field. The instanton contributions are…

High Energy Physics - Phenomenology · Physics 2017-08-23 Hilmar Forkel

We present a study of the QCD interactions which do not conserve the chirality of quarks. These non-perturbative forces are responsible for the violation of the U_A(1) charge conservation and for the breaking of chiral symmetry. From a…

High Energy Physics - Phenomenology · Physics 2007-05-23 P. Faccioli

We are discussing the influence of the complex structure of the QCD vacuum on the properties of the exotic multiquark states, specially the possibility for the existence of a deeply bound pentaquark. We show that the specific spin-flavor…

High Energy Physics - Phenomenology · Physics 2007-05-23 Hee-Jung Lee

Based on simulations of the interacting instanton liquid model (IILM) with three-flavor quarks, we compute the free energy density of the QCD vacuum as a function of the quark condensate. We then evaluate the second derivative of the free…

High Energy Physics - Phenomenology · Physics 2025-02-21 Yamato Suda , Daisuke Jido

We compute the vacuum energy density as a function of the quark condensate in the interacting instanton liquid model (IILM) and examine the pattern of dynamical chiral symmetry breaking from its behavior around the origin. This evaluation…

High Energy Physics - Phenomenology · Physics 2024-12-31 Yamato Suda , Daisuke Jido

We calculate the contribution of the instanton -- anti-instanton ($I\bar I$) pairs to the vacuum energy of QCD-like theories with $N_f$ light fermions using the saddle point method. We find a qualitative change of the behavior: for $N_f \ge…

High Energy Physics - Phenomenology · Physics 2009-10-30 M. Velkovsky , E. Shuryak

We calculate the leading direct-instanton contributions to the operator product expansion of the nucleon correlator in a magnetic background field and set up improved QCD sum rules for the nucleon magnetic moments. Remarkably, the instanton…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. Aw , M. K. Banerjee , H. Forkel

We study the role of direct (i.e. small-scale) instantons in QCD correlation functions for the nucleon. They generate sizeable, nonperturbative corrections to the conventional operator product expansion, which improve the quality of both…

High Energy Physics - Phenomenology · Physics 2009-10-22 Hilmar Forkel , Manoj K. Banerjee

We propose a mechanism for instanton induced chiral symmetry breaking in QCD with fundamental scalars. The model Lagragian that we use has the same symmetry properties as QCD. The scalar fields develop vacuum expectation values at a…

High Energy Physics - Phenomenology · Physics 2011-09-13 Rahul Basu , R. Parthasarathy

Instantons generate strong non-perturbative interactions between quarks. In the vacuum, these interactions lead to chiral symmetry breaking and generate constituent quark masses on the order of 300-400 MeV. The observation that the same…

High Energy Physics - Phenomenology · Physics 2009-10-31 R. Rapp , T. Schaefer , E. V. Shuryak , M. Velkovsky

The detailed analysis of nonperturbative contributions to the electromagnetic quark form factor is performed within the framework of the instanton liquid model (ILM) of the QCD vacuum. The method of the path-ordered Wilson exponentials is…

High Energy Physics - Phenomenology · Physics 2009-11-10 A. E. Dorokhov , I. O. Cherednikov

We discuss the role of instantons in the spectroscopy of ordinary and exotic hadrons as well as in high energy reactions. We argue that the instanton induced flavor- and spin-dependent quark-quark and quark-gluon interactions can explain…

High Energy Physics - Phenomenology · Physics 2008-10-06 N. I. Kochelev

Chiral quark model with a broken-U(3) flavor symmetry can be interpreted as the effective theory of the instanton-dominated non-perturbative QCD. This naturally suggests the possibility of a negative singlet/octet coupling ratio, which has…

High Energy Physics - Phenomenology · Physics 2009-10-31 T. P. Cheng , Ling-Fong Li

A brief summary on the Wigner rotation effect in the understanding of the proton spin ``crisis" related with the Ellis-Jaffe sum rule violation, and on the proton-neutron isospin symmetry breaking explanation of the Gottfried sum rule…

High Energy Physics - Phenomenology · Physics 2007-05-23 Bo-Qiang Ma

The aim of this review is to demonstrate that there exists a coherent picture of strong interactions, based on instantons. Starting from the first principles of QCD - via the microscopic mechanism of spontaneous chiral symmetry breaking -…

High Energy Physics - Phenomenology · Physics 2009-11-07 Dmitri Diakonov
‹ Prev 1 2 3 10 Next ›