Search for a Higgs boson decaying into γ∗γ → eeγ in pp collisions at √s = 8 TeV with the CMS detector

• Main Authors: Chiu-Ping Chang, 張秋萍
• Other Authors: Chia-Ming Kuo
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/pmc38s

碩士 === 國立中央大學 === 物理學系 === 104 === A search is described for a Higgs boson decaying into two photons, one of which has an internal conversion to an electron pair (eeγ). The analysis is performed using proton-proton collision data recorded with the CMS detector at the LHC at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.7/fb. The events selected have a merged electron caused by two close-by electrons from low mass γ* decay and a high transverse momentum photon. The results are combined with H ->γ*γ -> μμγ final state, where dimuon mass below 20 GeV. No excess above background has been found in the three-body invariant mass range 120 < m(llγ) < 150 GeV. The observed (expected) limit for Higgs mass = 125 GeV is about 7.62(9.97+4.81-3.10) times the SM prediction for H ->γ*γ -> eeγ, 10.79(7.59+3.78-2.36) times the SM prediction for H ->γ*γ -> μμγ and 6.7(5.9+2.8-1.8) times the SM prediction for combined channel.