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

Motivated by the recent observation of double charm quark pair production bythe Belle Collaboration, we calculate the complete ${\cal O}(\alpha_{s}^{2})$inclusive production cross sections for $\eta_{c}$, $J/\psi$, and$\chi_{cJ}$(J=0, 1, 2) plus $c\bar{c}$ in $e^+ e^-$ annihilation through avirtual photon. We consider both color-singlet and color-octet contributions,and give the analytical expressions for these cross sections. The completecolor-singlet calculations are compared with the approximate fragmentationcalculations as functions of the center-of-mass energy $\sqrt{s}$. We find thatmost of the fragmentation results substantially overestimate the cross sections(e.g. by a factor of $\sim$4 for $\chi_{c1}$ and $\chi_{c2}$) at the Belle andBaBar energy $\sqrt{s}=10.6$GeV. The fragmentation results become a goodapproximation only when $\sqrt{s}$ is higher than about 100GeV. We furthercalculate the color-octet contributions to these cross sections with analyticalexpressions. We find that while the color-octet contribution to $J/\psi$inclusive production via double charm is negligible (only about 3%), thecolor-octet contributions to $\chi_{c1}$ and $\chi_{c2}$ can be significant.Comment: 23 pages, 9 figures; color-octet contributions to the double charm  inclusive production of J/psi and chi_{cJ} (J=0,1,2) are added; references  are added; No change for the color-singlet par

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

Inclusive charmonium production via double<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>c</mml:mi><mml:mrow><mml:mrow><mml:mover><mml:mrow><mml:mi>c</mml:mi></mml:mrow><mml:mrow><mml:mi>¯</mml:mi></mml:mrow></mml:mover></mml:mrow></mml:mrow></mml:math>in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup></mml:mrow><mml:mrow><mml:…

Inclusive charmonium production via doublecc¯ine+