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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We implement a Monte Carlo sampling strategy to extract helicity partondensities and their uncertainties from a reference set of longitudinallypolarized scattering data, chosen to be that used in the DSSV14 globalanalysis. Instead of adopting the simplest possible functional forms for thehelicity parton distributions and imposing certain restrictions on theirparameter space in order to constrain them, we employ redundant, flexibleparametrizations and fit them to a large number of Monte Carlo replicas of theexisting data. The optimum fit and its uncertainty estimates are then assumedto be given by the statistical average of the obtained ensemble of replicas ofhelicity parton densities and their corresponding variance, respectively. Wecompare our results to those obtained by the traditional fitting approach andto the uncertainty estimates derived with the robust Lagrange multipliermethod, finding good agreement. As a first application of our new set ofreplicas, we discuss the impact of the recent STAR dijet data in furtherconstraining the elusive gluon helicity density through the reweighting method.

Monte Carlo sampling variant of the DSSV14 set of helicity parton densities