Colour flow connections within CMS detector at LHC collider

Full text: The search of the standard model low mass Higgs boson with the CMS detector at the proton-proton collider LHC at √s=7 TeV is very challenging.Thanks to the very reliable b-tagging and the recent studies of boosted topology, the H→bb-bar channel is getting within reach. Since the Higgs boson is a colour-singlet the two bs of its decay can only exchange colour flow between each other. On the other hand during the hadronization process of the decay products of coloured objects,such as gluons or quarks, the colour flow can be exchanged with the whole event. Properties of the colour connection between the jets can be used to distinguish the two bs of H→bb-bar from the two of the gluon splitting process (g→bb-bar), one of its most important backgrounds. A new event-by-event variable is shown to be able to distinguish signal-like and background-like events improving the signal over background ratio. (author)