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S. S. Agaev

Publications and source records attributed to S. S. Agaev.

93 records · Page 6Linked to original sources

Power corrections to the space-like transition form factor F_{η^{\prime}g^{*}g^{*}}(Q^2,ω)

Employing the standard hard-scattering approach (HSA) in conjunction with the running-coupling (RC) method, the latter joined with the infrared-renormalon calculus, we compute power-suppressed corrections $\sim 1/Q^{2n}, n=1, 2,...$ to the massless $η^{\prime}$ meson - virtual gluon transition form factor (FF) $Q^2F_{η^{\prime}g^{*}g^{*}}(Q^2,ω)$. Contributions to the form factor from the quark and gluon components of the $η^{\prime}$ meson are taken into account. Analytic expressions for the FF's $F_{η^{\prime}gg^{*}}(Q^2,ω=\pm 1)$ and $F_{η^{\prime}g^{*}g^{*}}(Q^2,ω=0)$ are also presented, as well as Borel transforms $B[Q^{2}F_{η^{\prime}g^{*}g^{*}}](u)$ and resummed expressions. It is shown that except for $ω=\pm 1, 0$, the Borel transform contains an infinite number of infrared renormalon poles. It is demonstrated that in the explored range of the total gluon virtuality $1 \rm {GeV}^{2} \leq Q^2 \leq 25 \rm {GeV}^{2}$, power corrections found with the RC method considerably enhance the FF $F_{η^{\prime}g^{*}g^{*}}(Q^{2}, ω)$ relative to results obtained only in the context of the standard HSA with a ``frozen'' coupling.

hep-ph↗

Light Mesons elm Form Factor and Running Coupling Effects

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 computations dependence of the meson 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. The effect of the next-to-leading order term in expansion of $α_{S}(λQ^2)$ in terms of $α_{S}(Q^2)$ on the pion form factor $F_π(Q^2)$ is discussed, comparison is made with the infrared matching scheme's result.

hep-ph↗

Single Meson Photoproduction via Higher Twist Mechanism and IR Renormalons

Single pseudoscalar and vector mesons hard semi-inclusive photoproduction $γh \to MX" via higher twist (HT) mechanism is calculated using the QCD running coupling constant method. The structure of infrared renormalon singularities of the HT subprocess cross section and the Borel sum for it are found. The problem of normalization of HT process cross section in terms of the meson elm form factor is discussed.

hep-ph↗