Abstract
Different heavy flavour production mechanisms are competing in hadronic collisions. Charm and bottom quark cross-sections are dominated by the pure QCD type of processes in which O({alpha}{sub s}{sup 2}) and O({alpha}{sub s}{sup 3}) diagrams are equally important. In the case of top quarks or members of families appearing in extensions of the minimal Standard Model, couplings of these particles may give rise to non-negligible contributions to heavy flavour production through weak currents. An `improved` tree level description of the calculation of the O({alpha}{sup 2}{alpha}{sub s}) boson-gluon fusion processes is presented, focussing on heavy fermions in the final state and the singular structure of expression for the matrix squared is analyzed in detail. At lowest order, that is O({alpha}{sup 2}) contributions from for instance W-bottom scattering, where the bottom quark flux is taken from the bottom quark distribution function in the proton, are deemed to give non-negligible contributions to the heavy flavour cross-sections. Adding O({alpha}{sup 2}) and O({alpha}{sup 2}{alpha}{sub s}) cross-sections will lead to a typical double counting of Feynman graphs and a solution to this problem is presented by subtracting the collinear singularity in the W-gluon fusion process. The results obtained are finite and, although virtual corrections have not explicitly
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Anselmo, F;
Eijk, B van;
[1]
Bordes, G
[2]
- European Organization for Nuclear Research, Geneva (Switzerland)
- College de France, 75 - Paris (France). Lab. de Physique Corpusculaire
Citation Formats
Anselmo, F, Eijk, B van, and Bordes, G.
On the factorisation theorem in boson-gluon fusion at hadron colliders.
Netherlands: N. p.,
1991.
Web.
Anselmo, F, Eijk, B van, & Bordes, G.
On the factorisation theorem in boson-gluon fusion at hadron colliders.
Netherlands.
Anselmo, F, Eijk, B van, and Bordes, G.
1991.
"On the factorisation theorem in boson-gluon fusion at hadron colliders."
Netherlands.
@misc{etde_10145392,
title = {On the factorisation theorem in boson-gluon fusion at hadron colliders}
author = {Anselmo, F, Eijk, B van, and Bordes, G}
abstractNote = {Different heavy flavour production mechanisms are competing in hadronic collisions. Charm and bottom quark cross-sections are dominated by the pure QCD type of processes in which O({alpha}{sub s}{sup 2}) and O({alpha}{sub s}{sup 3}) diagrams are equally important. In the case of top quarks or members of families appearing in extensions of the minimal Standard Model, couplings of these particles may give rise to non-negligible contributions to heavy flavour production through weak currents. An `improved` tree level description of the calculation of the O({alpha}{sup 2}{alpha}{sub s}) boson-gluon fusion processes is presented, focussing on heavy fermions in the final state and the singular structure of expression for the matrix squared is analyzed in detail. At lowest order, that is O({alpha}{sup 2}) contributions from for instance W-bottom scattering, where the bottom quark flux is taken from the bottom quark distribution function in the proton, are deemed to give non-negligible contributions to the heavy flavour cross-sections. Adding O({alpha}{sup 2}) and O({alpha}{sup 2}{alpha}{sub s}) cross-sections will lead to a typical double counting of Feynman graphs and a solution to this problem is presented by subtracting the collinear singularity in the W-gluon fusion process. The results obtained are finite and, although virtual corrections have not explicitly been taken into account, are expected to be valid for almost full phase space. Similar conclusions can be drawn in the case where the charged weak current is replaced by the neutral weak current. {gamma}/Z{sup 0} interference is taken into account as well. (author). 17 refs., 5 figs., 4 tabs.}
place = {Netherlands}
year = {1991}
month = {Dec}
}
title = {On the factorisation theorem in boson-gluon fusion at hadron colliders}
author = {Anselmo, F, Eijk, B van, and Bordes, G}
abstractNote = {Different heavy flavour production mechanisms are competing in hadronic collisions. Charm and bottom quark cross-sections are dominated by the pure QCD type of processes in which O({alpha}{sub s}{sup 2}) and O({alpha}{sub s}{sup 3}) diagrams are equally important. In the case of top quarks or members of families appearing in extensions of the minimal Standard Model, couplings of these particles may give rise to non-negligible contributions to heavy flavour production through weak currents. An `improved` tree level description of the calculation of the O({alpha}{sup 2}{alpha}{sub s}) boson-gluon fusion processes is presented, focussing on heavy fermions in the final state and the singular structure of expression for the matrix squared is analyzed in detail. At lowest order, that is O({alpha}{sup 2}) contributions from for instance W-bottom scattering, where the bottom quark flux is taken from the bottom quark distribution function in the proton, are deemed to give non-negligible contributions to the heavy flavour cross-sections. Adding O({alpha}{sup 2}) and O({alpha}{sup 2}{alpha}{sub s}) cross-sections will lead to a typical double counting of Feynman graphs and a solution to this problem is presented by subtracting the collinear singularity in the W-gluon fusion process. The results obtained are finite and, although virtual corrections have not explicitly been taken into account, are expected to be valid for almost full phase space. Similar conclusions can be drawn in the case where the charged weak current is replaced by the neutral weak current. {gamma}/Z{sup 0} interference is taken into account as well. (author). 17 refs., 5 figs., 4 tabs.}
place = {Netherlands}
year = {1991}
month = {Dec}
}