Related papers: Instantons, Spin Crisis and High $Q^2$ Anomaly at …
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…
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…
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…
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…
It is shown that the contribution of the instantons to the fragmentation of quarks leads to the appearance of a imaginary part in diagrams of quark-quark scattering at large transfer momentum. The imaginary part comes from the analytical…
It is by now well understood that spin asymmetry in deep inelastic scattering (DIS) can appear if two things are both present: (i) a chirality flip of the struck quark; (ii) a nonzero T-odd phase due to its final state interaction. So far…
We compute the decay rate for the process $\eta_c\to p\bar p$ using an effective helicity-flipping proton-antiproton-gluon vertex which incorporates nonperturbative chiral symmetry breaking effects induced by instantons. We fix the strength…
The contribution of the anomalous quark-gluon interaction induced by instantons to the polarized and unpolarized gluon distributions in nucleon is estimated. It is shown that this interaction leads to negative gluon polarization in nucleon.
In quantum chromodynamics (QCD), the role which topologically non-trivial configurations play in splitting the singlet pseudo-Goldstone meson, the $\eta^\prime$, from the octet is familiar. In addition, such configurations contribute to…
The drastic rise of the proton structure function F_2(x,Q^2) when the Bj\"orken variable x decreases, seen at HERA for a large span of Q^2, negative values for the 4-momentum transfer, may be damped when Q^2 increases beyond several…
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…
The spin structure function $g_1^p$ of the proton is studied in a two component framework, where the perturbative evolution of parton distributions and nonperturbative vector meson dominance model are used. We predict the $g_1^p$ asymmetric…
QCD instantons generate non-perturbative spin- and flavor- dependent forces between quarks. We review the results of a series of studies on instanton-induced correlations in hadrons. We first present some evidence for instanton-mediated…
We phenomenologically study whether partonic collisions responsible for the growth of hadron-hadron cross sections at high energy can be ascribed to instanton-induced processes. Although non-perturbative in nature, these interactions occur…
We present a first status report on a broad and systematic study of possible manifestations of QCD-instantons at HERA. Considerable motivation comes from the close analogy between instanton-induced $B+L$ violation in electroweak processes…
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…
We show that the rise in $F_2^p$ at small $x$ and large $Q^2$ seen at HERA is indeed the non-Regge double asymptotic scaling behaviour expected from the perturbative emission of strongly ordered hard gluons. An alternative explanation, in…
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…
Signals of QCD instanton-induced processes are searched for in neutral current deep-inelastic scattering at the electron-proton collider HERA in the kinematic region defined by the Bjorken-scaling variable $x > 10^{-3}$, the inelasticity…
After a brief introduction into the phenomenology of instantons, results from instanton perturbation theory applied to deep-inelastic electron proton scattering are summarized. Based on event signatures derived from Monte Carlo studies,…