Measurement of Charm Meson Pair Cross Sections


We present a study of prompt charm meson pair production in p p collisions at a center-of-mass energy of 1.96 TeV. Both charm mesons of the pair are fully reconstructed in hadronic decay modes. Correlations of the two charm mesons are used to study heavy-quark production dynamics. Collionear production is found to be as important as back-to-back production. The measured pair cross sections are compared to a leading order matrix element plus parton shower model (Pythia Tune A), which gives a fair estimate of the absolute pair cross section, but underestimates (overestimates) collinear (back-to-back) production of charm meson pairs.

A brief summary writeup of the double charm analysis (Beauty06 Proceedings) is here

This result has been first presented on the Beauty 2006 Conference at Oxford, UK.
The pdf file of the talk is available here .

More details of this analysis can by found in this talk
at the Particle Physics Seminar at the University of Bonn, Germany.


Figures

Below are the eps and gif versions of the most interesting figures:
  • Charm meson pair cross sections
  • Inclusive charm meson yields
  • Yields of charm meson pairs
  • Variables separating prompt from secondary pairs
  • Data Monte Carlo Comparisons
    • These figures superseed the PR plots of D0D*- pairs for L = 370 pb-1



    Cross Sections

    Integrated Cross Sections

    Integrated D0D*- cross section vs ΔφThe D0D*- pair cross section as function of Δφ. The transverse momentum , pT, and pseudo rapidity, y,  ranges are given on the plot.

    The measurements (points) are compared to the leading order matrix element plus parton shower event generator Pythia (Tune A ) (black line). Also shown are the contributions of the leading order production mechanisms flavor creation (red), flavor excitation (green) and gluon splitting (blue).

    Click here to retrieve  the eps or the gif file of the plot. Back to list of figures.
    Integrated D+D*- cross section vs ΔφThe D+D*- pair cross section as function of Δφ The transverse momentum , pT, and pseudo rapidity, y,  ranges are given on the plot.

    The measurements (points) are compared to the leading order matrix element plus parton shower event generator Pythia (Tune A ) (black line). Also shown are the contributions of the leading order production mechanisms flavor creation (red), flavor excitation (green) and gluon splitting (blue).

    Click here to retrieve  the eps or the gif file of the plot. Back to list of figures.

    An additional plot of the D0D*- pair cross section with the same trigger side D pT range as for D+D*- pair cross section the is available in eps and gif format.


    Differential Cross Sections

    D0D*- cross section vs Δφ in bins of trigger side PTThe D0D*- pair cross section
    as function of Δφ in bins
    of trigger side D0 pT.

    The transverse momentum , pT, and pseudo rapidity, y,  ranges are given on the plot.

    The measurements (points) are compared to the leading order matrix element plus parton shower event generator Pythia (Tune A ) (black line).

    Click here to retrieve  the eps or the gif file of the plot. Back to list of figures.
    Integrated D+D*- cross section vs ΔφThe D+D*- pair cross section
    as function of Δφ in bins
    of trigger side D+ pT.

    The transverse momentum , pT, and pseudo rapidity, y,  ranges are given on the plot.

    The measurements (points) are compared to the leading order matrix element plus parton shower event generator Pythia (Tune A ) (black line).
    Click here to retrieve  the eps or the gif file of the plot. Back to list of figures.


    Burkard Reisert
    Last modified: Wed Sep 22 21:02:18 CST 2006