Measurement of the spin and parity of the new boson discovered in ATLAS experiment at the LHC

par Kirill Prokofiev (New York University - ATLAS)

lundi 28 janv. 2013, 14:00 → 15:00 Europe/Paris

Amphithéâtre (CPPM)

In summer 2012 the CMS and ATLAS experiments at the LHC reached an important milestone. A new boson with a mass around 126 GeV was discovered in the combination of searches for the Higgs boson in H → γγ, H → ZZ (∗) → 4l and H → W W decays. The observed production and decay modes are compatible with those predicted for the Standard Model Higgs boson. However, in order to prove that the newly discovered particle is the Higgs boson responsible for the mechanism of the electroweak symmetry breaking and the mass generation of elementary particles, its quantum numbers should be determined and couplings to other particles and self-couplings measured. In the Standard Model the Higgs boson is a CP-even, spin zero particle. Beyond the Standard Model the electroweak symmetry breaking can lead to multiple Higgs states with even and odd CP quantum numbers. If CP is violated in the Higgs sector then the physical Higgs states with mixed CP could exist. In this presentation the options for spin and parity of the newly observed Higgs-like boson will be discussed. The present status of ATLAS spin and parity measurements will be presented and the prospects for the near future will be given. In addition, the possibility of experimental observation of the CP-violation effects in the Higgs sector with the ATLAS detector will be discussed.

Transparents SeminarSpin_prokofiev.pptx.pdf