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Instanton effects can give large contribution to strong interacting processes, especially at the energy scale where perturbative QCD is no longer valid. However instanton contribution to the gluon contribution in constituent quark and…

High Energy Physics - Phenomenology · Physics 2018-08-01 Baiyang Zhang , Nikolai Kochelev , Hee-Jung Lee , Pengming Zhang

QCD suggests that gluons in the nucleon play an important role in {\it so-called} ``the proton spin problem''. In this talk, the behavior of the polarized gluon distribution in the nucleon is discussed by using the positivity condition of…

High Energy Physics - Phenomenology · Physics 2009-09-25 T. Morii , S. Tanaka , T. Yamanishi

Instantons are the natural mechanism in non-perturbative QCD to remove helicity from valence quarks and transfer it to gluons and quark-antiquark pairs. To understand the extent to which instantons explain the so-called "spin crisis" in the…

High Energy Physics - Lattice · Physics 2008-11-26 D. Dolgov , R. Brower , J. W. Negele , A. Pochinsky

Based on both the constituent quark picture and the instanton model for QCD vacuum, we calculate the unpolarized and polarized gluon distributions in the constituent quark and in the nucleon. Our approach consists of the two main steps. At…

High Energy Physics - Phenomenology · Physics 2016-05-04 Nikolai Kochelev , Hee-Jung Lee , Baiyang Zhang , Pengming Zhang

We calculate the spin density matrix of a back-to-back quark-antiquark pair inclusively produced in electron-nucleus scattering, taking into account the gluon saturation effect and the linearly polarized gluon distribution. We then…

High Energy Physics - Phenomenology · Physics 2026-04-14 Michael Fucilla , Yoshitaka Hatta , Bo-Wen Xiao

A new mechanism for single spin asymmetries in strong interaction is proposed. It is based on instanton-induced nonperturbative chromomagnetic quark-gluon interaction. We estimate the contribution of this interaction to single spin…

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

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 contribution of the nonperturbative quark-gluon interaction induced by the instantons to $g_1^p(x,Q^2)$ and $F_2^p(x,Q^2)$ structure functions is estimated. It is shown that nontrivial $Q^2$ dependence of the instanton contribution to…

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

We calculate the contribution arising from nonperturbative quark-gluon chromomagnetic interaction to the high energy total quark-quark cross section and to gluon distributions in nucleon. The estimation obtained within the instanton model…

High Energy Physics - Phenomenology · Physics 2014-11-20 Nikolai 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

The instanton-induced multiple events in high energy collisions are considered in nonperturbative quantum chromodynamics. Here we obtained unusual behaviour of ratio of correlation moments Hq for such processes which can be used for…

High Energy Physics - Phenomenology · Physics 2011-03-17 V. Kuvshinov , R. Shulyakovsky

We study how gluons carrying linear polarization inside an unpolarized hadron contribute to the transverse momentum distribution of Higgs bosons produced in hadronic collisions. They modify the distribution produced by unpolarized gluons in…

High Energy Physics - Phenomenology · Physics 2012-01-20 Daniel Boer , Wilco J. den Dunnen , Cristian Pisano , Marc Schlegel , Werner Vogelsang

This contribution to CIPANP 2012 highlights what we have learned about the asymmetric parton distributions of the nucleon over the past 20 years. These distributions include the transverse momentum dependent parton distributions describing…

High Energy Physics - Phenomenology · Physics 2015-06-11 Daniel Boer

Linear polarization of gluons inside unpolarized hadrons affects the transverse momentum distribution of produced spin-0 particles, such as of the Higgs or (pseudo-)scalar quarkonium states at LHC. Despite the currently unknown amount of…

High Energy Physics - Phenomenology · Physics 2015-10-21 Daniël Boer

It is shown that the amplitude for the scattering of a heavy quarkonium system from a nucleon near threshold is completely determined by the fraction of angular momentum, as well as linear momentum, carried by gluons in the nucleon. A form…

High Energy Physics - Phenomenology · Physics 2009-10-31 Pervez Hoodbhoy

Linearly polarized gluons inside an unpolarized proton contribute to the transverse momentum distributions of (pseudo)scalar particles produced in hadronic collisions, such as Higgs bosons and quarkonia with even charge conjugation…

High Energy Physics - Phenomenology · Physics 2015-06-23 Cristian Pisano

It is shown that the instanton-induced interaction in qq pairs, iterated in t-channel, leads to a meson-exchange interactions between quarks. In this way one can achieve a simultaneous understanding of low-lying mesons, baryons and the…

High Energy Physics - Phenomenology · Physics 2009-10-31 L. Ya. Glozman , K. Varga

We report on a calculation of one-loop weak corrections to polarized quark-gluon scattering and the corresponding crossed channels. Such contributions are suppressed formally by one power of alpha_s relative to W- or Z-mediated quark-quark…

High Energy Physics - Phenomenology · Physics 2009-11-07 John Ellis , Stefano Moretti , Douglas Ross

The distribution of the spin of the nucleon among its constituents can be parametrized in the form of polarized parton distribution functions for quarks and gluons. Using all available data on the polarized structure function $g_1(x,Q^2)$,…

High Energy Physics - Phenomenology · Physics 2014-11-17 T. Gehrmann , W. J. Stirling

We show that the instanton-induced inelastic processes, leading to multi-gluon production in in high-energy parton-parton scattering, are considerably enhanced over the quasi-elastic ones, by a factor of 100. The basic instanton-induced…

High Energy Physics - Phenomenology · Physics 2009-10-31 Maciek A. Nowak , Edward V. Shuryak , Ismail Zahed
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