High Energy Physics Seminars

The recently discovered Higgs boson is a completely new form of matter-energy and is believed to be a manifestation of the all-penetrating field responsible for generating mass of all elementary particles. It was observed as a resonance with mass near 125 GeV in the decay to a pair of two vector bosons on the ATLAS and CMS experiments at LHC in 2012. It is expected to have the width of about 4 MeV and the quantum numbers of the vacuum (J^PC=0^++). Yet experimental resolution allowed us to set an upper limit on the width of about 3400 MeV and only a limited number of spin-parity assignments were tested until recently. Two recent results from the CMS experiment provided a breakthrough in the study of the H boson properties: one is the measurement of the width from an interplay between the off-shell and on-shell production of the H boson, leading to a 22 MeV limit on the width, and the other is the tensor structure measurement of the H boson interactions with four pairs of vector bosons, leading to constraints on its spin-parity properties. Both results will be discussed.