English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We develope the method of improvement of perturbative theory in QCD, appliedto any polarization operator. The case of polarization operator \Pi(q^2),corresponding to the process e^+e^- -> hadrons is considered in details. Usingthe analytical properties of \Pi(q^2) and perturbative expansion of \Pi(q^2) atq^2<0, Im\Pi(q^2) at q^2>0 is determined in such a way, that the infared poleis eliminated. The convergence of perturbative series for R(q^2)=\sigma(e^+e^--> hadrons)/(e^+e^- -> \mu^+\mu^-) is improved. After substitution of R(q^2)into dispersion relation the improved Adler function D(q^2) with no infraredpole and frozen \alpha_s(q^2) has been obtained. A good agreement withexperiment has been achieved.Comment: 4 pages, latex; 2 references are adde

Improvement of perturbation theory in QCD for e + e − →hadrons and the problem of α s freezing