Speaker
Antoni Szczurek
(Institute of Nuclear Physics)
Description
We discuss the diffractive dissociation of gluons into heavy quark pairs.
The particular mechanism is similar to the diffractive dissociation
of virtual photons into quarks, which drives diffractive deep inelastic
production of charm in the low-mass diffraction, or large $\beta$-region.
The amplitude for the $g p \to Q \bar Q p$ is derived in the impact
parameter and momentum space. The cross section for single diffractive
$p p \to Q \bar Q p X$ is calculated as a convolution of the elementary
cross section and gluon distribution in the proton.
Both the integrated and the differential distributions in e.g. transverse
momentum and rapidity of the charm and bottom quark and antiquark,
quark-antiquark invariant mass are calculated for the nominal LHC energy
for different unintegrated gluon distributions from the literature.
The model leads to much smaller fractional longitudinal momentum losses
than in the Ingelman-Schlein (IS) model. Quark and antiquark are produced
exclusively either in the $y_1, y_2>$ 0 region or in
the $y_1, y_2<$ 0 region. The gluon dissociation contributes into
the region of very small $x_{IP}$, much smaller than in the
Ingelman-Schlein model with absorption.
These characteristics can be used to separate the present mechanism from
the Ingelman-Schlein one.
The ratio of the bottom-to-charm cross sections are shown and discussed.
Author
Antoni Szczurek
(Institute of Nuclear Physics)
Co-author
Wolfgang Schaefer
(Institute of Nuclear Physics PAN)
