Diffractive dissociation of gluons into heavy quark–antiquark pairs in proton–proton collisions

We discuss 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 β-region. There, it can be understood, with some reservations, in terms of a valence heavy quark content of the Pomeron. The amplitude for the <math altimg="si1.gif" xmlns="http://www.w3.org/1998/Math/MathML"><mi>g</mi><mi>p</mi><mo>→</mo><mi>Q</mi><mover accent="true"><mrow><mi>Q</mi></mrow><mrow><mo>¯</mo></mrow></mover><mi>p</mi></math> is derived in the impact parameter and momentum space. The cross section for single diffractive <math altimg="si2.gif" xmlns="http://www.w3.org/1998/Math/MathML"><mi>p</mi><mi>p</mi><mo>→</mo><mi>Q</mi><mover accent="true"><mrow><mi>Q</mi></mrow><mrow><mo>¯</mo></mrow></mover><mi>p</mi><mi>X</mi></math> is calculated as a convolution of the elementary cross section and gluon distribution in the proton. Integrated cross section and the differential distributions in e.g. transverse momentum and rapidity of the charm and bottom quark and antiquark, as well as the quark–antiquark invariant mass are calculated for the nominal LHC energy for different unintegrated gluon distributions from the literature. The ratio of the bottom-to-charm cross sections are shown and discussed as a function of several kinematical variables