The SM Higgs searching in the H->cc decay channel


  Tingting Cao  
Tel Aviv University

In the Standard Model of particle physics (SM), the Higgs boson results from the Brout- Englert-Higgs mechanism, which is needed to give mass to the W and Z gauge bosons and to the fermions. During the Run-1 of the LHC, a Higgs boson-like particle was discovered by the ATLAS and CMS collaborations. Since the discovery, the ATLAS and CMS experiments have precisely measured the new boson properties. The mass, obtained by combining the ATLAS and CMS Run-1 measurements, is equal to 125.09 ± 0.24 GeV. The measured spin- parity is consistent with the SM Higgs boson expectation of JP = 0+. The production and decay rates, and coupling to bosons and fermions were also recently measured by the ATLAS and CMS collaborations, and are in agreement with the predictions for a SM Higgs boson: significant Higgs boson signals decaying to a pair of photons, Z and W bosons, and τ leptons, were observed in Run-1. However, in the H b ̄b decay channel, with the large branching ratio (58%), the Higgs boson has not yet been observed. An observed of significance of 2.6 standard deviations (and an expected significance of 3.7 σ) is obtained at the end of Run-1. An observation of the decay to a pair of b-quarks is still one of the milestones of the LHC experiments physics programme during Run-2. Besides, the more challenging work is to search the Higgs in the H cc ̄ decay channel with branch ration 3%. This work was completely missed for the whole Run-1. The new technique achievement of c-tagging, similarly with b-tagging, provides a chance to make an observation of the decay to a pair of c-quarks. This talk will show that how to use the similar method in the H b ̄b decay channel, to search the Higgs boson in the H cc ̄ decay channel in Run-2.