arXiv subjects

Shahin S. Agaev

Publications and source records attributed to Shahin S. Agaev.

4 recordsLinked to original sources

arXiv1998

The running coupling method with next-to-leading order accuracy and pion, kaon elm form factors

The pion and kaon electromagnetic form factors $F_M(Q^2)$ are calculated at the leading order of pQCD using the running coupling constant method. In calculations the leading and next-to-leading order terms in $α_S((1-x)(1-y)Q^2)$ expansion in terms of $α_S(Q^2)$ are taken into account. The resummed expression for $F_M(Q^2)$ is found. Results of numerical calculations for the pion (asymptotic distribution amplitude) are presented.

hep-ph↗

arXiv1998

IR renormalon effects and light mesons' elm form factor

The pion and kaon electromagnetic form factors $F_M(Q^2)$ are calculated at the leading order of pQCD using the running coupling constant method. In calculations a dependence of the mesons distribution amplitudes on the hard scale $Q^2$ is taken into account. The Borel transform and resummed expression for $F_M(Q^2)$ are found.

hep-ph↗

arXiv1996

Single meson photoproduction and IR renormalons

Single pseudoscalar and vector mesons inclusive photoproduction $γh\rightarrow MX$ via higher twist mechanism is calculated using the QCD running coupling constant method. It is proved that in the context of this method a higher twist contribution to the photoproduction cross section cannot be normalized in terms of the meson electromagnetic form factor. The structure of infrared renormalon singularities of the higher twist subprocess cross section and the resummed expression (the Borel sum) for it are found. Comparisons are made with earlier results, as well as with leading twist cross section. Phenomenological effects of studied contributions for $π, K, ρ$-meson photoproduction are discussed.

hep-ph↗

arXiv1996

Resummation of infrared renormalons in the pion electromagnetic form factor calculations

The pion electromagnetic form factor F_π(Q^{2}) is calculated at the leading order of pQCD using the running coupling constant (α_{S}(Q^{2}(1-x)(1-y))) approach. The resummed expression for F_π(Q^{2}) is found. It is shown that the effect of the infrared renormalons can be taken into account by scale-setting procedure $α_{S}(Q^{2}) \rightarrow α_{S}(e^{f(Q^{2})}Q^{2})$ in the leading order expression

hep-ph↗