Related papers: Soft Contribution to Quark-Quark Scattering Induce…
It is shown that the quark-gluon interaction induced by instantons leads to the quark anomalous chromomagnetic moment. In the instanton-liquid model for the QCD vacuum, the chromomagnetic moment is $\mu_a=-\frac{\pi f}{2\alpha_s}$, where f…
We present the computation of the soft-parton contribution at low transverse momentum for the production of a heavy quark pair in association with a colour singlet at the next-to-next-to-leading order (NNLO) in the QCD coupling. This paper…
Prompt photon production is sensitive to the anomalous couplings of gluons to quarks, because it is mainly produced by quark-gluon scattering. We will examine the effects of the anomalous chromoelectric and chromomagnetic dipole moment…
The role of the QCD vacuum effects in high energy diffractive quark-quark and quark-antiquark scattering is studied with the Instanton Liquid Model. The special attention is given to the problem of formation of the soft Pomeron. We show…
We consider elastic quark-quark scattering at high energy with fixed momentum transfer $t$ and perform factorization of soft-gluon exchanges into a vacuum expectation value of Wilson lines. Taking into account nonperturbative corrections…
Instanton-induced deep-inelastic processes are considered. Unlike previous results we calculate nonzero quark modes contribution.
It is shown that existence of a large anomalous chromomagnetic moment of quark induced by non-perturbative structure of QCD leads to the additional contribution to exclusive $\rho$-meson electroproduction off proton target. The significant…
The nonperturbative effects in the high-energy processes involving strongly interacting particles are studied within the instanton liquid model of the QCD vacuum (ILM) by using the Wilson integral framework. The detailed analysis of…
The effect of perturbative QCD interactions on the high energy scattering of electroweak vector bosons, when the exchanged channel has pion quantum numbers, is considered. The chiral anomaly is shown to appear in the couplings of particular…
We discuss the hadronic contributions to the muon anomalous magnetic moment. They are dominated by light quark contributions which are constrained by the mechanism of chiral symmetry breaking. Using the leading order result based on $e^+…
The role of transverse momentum of quarks in semi-inclusive leptoproduction will be discussed. It involves generalized distribution and fragmentation functions which depend on both the longitudinal lightcone momentum fraction of the quarks…
We disscuss a new nonperturbative mechanism for spin effects in high energy reactions with hadrons. This mechanism is based on the existence of a large anomalous quark chromomagnetic moment (AQCM) induced by the nontrivial topological…
We discuss a method for calculating the heavy quark vacuum polarisation contribution to the muon anomalous magnetic moment, $a_\mu$, using perturbative QCD. This approach is independent of $e^+e^-$ cross-section data allowing a fully…
The analysis of nonperturbative effects in high energy asymptotics of the electomagnetic quark form factor is presented. It is shown that the nonperturbative effects determine the initial value for the perturbative evolution of the quark…
The hadronic light-by-light scattering contribution to the muon anomalous magnetic moment can be estimated by computing constituent quark loops. Such an estimate is very sensitive to the numerical values of the constituent quark masses.…
We consider QCD radiative corrections to the production of a heavy-quark pair in hadronic collisions. We present the computation of the soft-parton contributions at low transverse momentum of the heavy-quark pair up to second order in the…
We compute the one-loop QCD correction to the photon-quark-antiquark vertex in an extremely strong magnetic background, i.e., one in which $\sqrt{eB}$ is much larger than all other mass scales. We resort to the lowest-Landau level…
We study the contribution to the proton's magnetic moment from a heavy quark sea in quantum chromodynamics. The heavy quark is integrated out perturbatively to obtain an effective dimension-6 magnetic moment operator composed of three gluon…
We estimate the contribution of nonperturbative quark-gluon chromomagnetic interaction to the high energy elastic proton-proton cross section at large momentum transfer. It is shown that this contribution is very large in the accessible…
We study light quark interactions in the instanton liquid at finite quark/baryon number density analyzing chiral and diquark condensates and investigate the behaviors of quark dynamical mass and both condensates together with instanton…