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 Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

When the allowed range of an observable grows order-by-order in perturbationtheory, its perturbative expansion can have discontinuities (as in the $C$parameter) or discontinuities in its derivatives (as in thrust or heavy jetmass) called Sudakov shoulders. We explore the origin of these logarithms usingboth perturbation theory and effective field theory. We show that for thrustand heavy jet mass, the logarithms arise from kinematic configurations withnarrow jets and deduce the next-to-leading logarithmic series. Theleft-shoulder logarithms in heavy jet mass ($\rho$) of the form $r\ \alpha_s^n\ln^{2n}r $ with $r=\frac{1}{3}-\rho$ are particularly dangerous, because theyinvalidate fixed order perturbation theory in regions traditionally used toextract $\alpha_s$. Although the factorization formula shows there are nonon-global logarithms, we find Landau-pole like singularities in the resummeddistribution associated with the cusp anomalous dimension, and that powercorrections are exceptionally important.

Sudakov Shoulder Resummation for Thrust and Heavy Jet Mass