In the forthcoming high-luminosity phase at the LHC many of the most interesting measurements for precision QCD studies are hampered by conditions of large pile-up, particularly at not very high transverse momenta. We study observables based on measu
ring ratios of color-singlet currents via Higgs boson and Drell-Yan production, which may be accessed also at large pile-up, and used for an experimental program on QCD physics of gluon fusion processes in the LHC high-luminosity runs. We present results of Monte Carlo calculations for a few specific examples.
If large-angle multigluon radiation contributes significantly to parton showers associated with heavy boson production at the LHC, appropriate parton branching methods are required for realistic Monte Carlo simulations of final states. We report on a
study illustrating such effects in the case of central scalar-boson production. We comment on the possible impact of such studies on the modeling of multi-parton interactions.
