Measurements Of The Decay Branching Fractions Of H?b(?)/c(?)/gg At The CEPC

The Higgs boson is a very important elementary particle in the standard model.The study of the Higgs boson properties is essential to perfecting the standard model and will even open the door to new physics.The measurement on Higgs boson parameters with high precision is one of the primary goals of the high energy Circular Electron Positron Collider(CEPC)The standard model predicts that the mass of 125 GeV Higgs boson will decay into a pair of jets:b-quarks(57.8%),c-quarks(2.7%)or gluons(8.6%).In the separation of these processes,the key step is the flavor tagging.The main research process of this paper can be divided into three stepsFirstly,the inclusive study of ZH production inl+l-Hwas done,and the required lepton pairs are selected by a series of cuts.The ZH events number are extracted by fitting the lepton pair recoil mass spectrumSecondly,the cuts on jets information are applied,to further suppress the backgrounds Finally,a fit was applied on both the flavor tagging information and lepton pair recoil mass,to extract the events number of ZH?ll?b(?)/c(?)/ggA study on the measurements of ZH?l(?)?b(?)/c(?)/gg decay branching ratios in CEPC experiment is presented,in the scenario of an integrated luminosity of 5000 fb-1 is assumed in the analysis,corresponding to 10 years of data taking with nominal luminosity of 2×1034cm-2s-1 at the CEPC.The branch ratio of Higgs decay can be calculated by dividing the individual ZH?ll?b(?)/c(?)/gg number by the inclusive ZH?l+l-H numberIn the study the Higgs boson is produced in association with a pair of leptons,dominantly following the Higgsstrahlung process.The statistic uncertainty is estimated around 1%while the systematic uncertainty are also discussed.This study demonstrate the potential of mearsuring Higgs boson hadronic decay in CEPC,and will provide key information to understand the Yukawa coupling between Higgs and quarks.