Higgs boson production at hadron colliders with soft gluon effects: Backgrounds

The gold-plated discovery mode of a standard model like Higgs boson at the CERN Large Hadron Collider (LHC) is the $\overrightarrow{H}{Z}^0{Z}^0$ decay mode. To find and then measure the properties of the Higgs boson, it is crucial to have the most precise theoretical prediction both for the signal and the QCD background in this mode. In this work we calculate the effects of the initial-state multiple soft-gluon emission on the kinematic distributions of $Z^0$ boson and photon pairs produced in hadron collisions. The Collins-Soper-Sterman formalism is extended to resum the large logarithmic terms due to soft gluons. The resummed total rates, the invariant mass, transverse momentum, and rapidity distributions of the $Z^0$ and photon pairs, and the transverse momentum distributions of the individual vector bosons are presented and compared to the fixed order predictions in the whole kinematic range, for the LHC energies and for the upgraded Fermilab Tevatron. Our conclusion is that the resummed predictions should be used when extracting the Higgs signal at the LHC.