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

The double parton distributions (dPDF), both conventional and thosecorresponding to parton splitting, are calculated and compared for differenttwo-parton combinations. The conventional and splitting dPDFs have very similarshape in $x_1$ and $x_2$. We make a first quantitative evaluation of thesingle-ladder-splitting contribution to double parton scattering (DPS)production of two S- or P-wave quarkonia, two Higgs bosons and $c \bar c c \barc$. The ratio of the single-ladder-splitting to conventional contributions isdiscussed as a function of centre-of-mass energy, mass of the produced systemand other kinematical variables. Using a simple model for the dependence of theconventional two-parton distribution on transverse parton separation (Gaussianand independent of $x_i$ and scales), we find that the 2v1 contribution is asbig as the 2v2 contribution discussed in recent years in the literature. Thismeans that the phenomenological analyses of $\sigma_{eff}$ including only theconventional DPS mechanism have to be revised including explicitly thesingle-ladder-splitting contributions discussed here. The differentialdistributions in rapidity and transverse momenta calculated for conventionaland single-ladder-splitting DPS processes are however very similar which causestheir experimental separation to be rather difficult, if not impossible. Thedirect consequence of the existence of the two components (conventional andsplitting) is the energy and process dependence of the empirical parameter$\sigma_{eff}$. This is illustrated in our paper for the considered processes.

physical review. d. particles, fields, gravitation, and cosmology/physical review. d, particles, fields, gravitation, and cosmology

Conventional versus single-ladder-splitting contributions to double  parton scattering production of two quarkonia, two Higgs bosons and $c \bar c  c \bar c$