This paper presents the prospects of measuring σ(e^(+)e^(-)→ZH)× Br(H→γγ) in three Z decay channels Z→qq/μ^(+)μ^(-)/vv using the baseline detector with √s=240GeV at the Circular Electron Positron Collide...This paper presents the prospects of measuring σ(e^(+)e^(-)→ZH)× Br(H→γγ) in three Z decay channels Z→qq/μ^(+)μ^(-)/vv using the baseline detector with √s=240GeV at the Circular Electron Positron Collider(CEPC).Simulated Monte Carlo events were generated and scaled to an integrated luminosity of 5.6 ab^(-1) to mimic the data.Extrapolated results to 20 ab^(-1) are also reported.The expected statistical precision of these measurements after combining three channels of Z boson decay was 7.7%.With some preliminary estimation on the systematical uncertainties,the total precision is 7.9%.The performance of the CEPC electro-magnetic calorimeter(ECAL) was studied by smearing the photon energy resolution in simulated events in the e^(+)e^(-)→ZH→qqγγ channel.In the present ECAL design,the stochastic term in resolution plays the dominant role in the precision of Higgs measurements in the H→γγ channel.The impact of the resolution on the measured precision of σ(ZH)×Br(ZH→qqγγ) as well as the optimization of the ECAL constant and stochastic terms were studied for further detector design.展开更多
The discovery of the Higgs boson with its mass around 125 GeV by the ATLAS and CMS Collaborations marked the beginning of a new era in high energy physics.The Higgs boson will be the subject of extensive studies of th...The discovery of the Higgs boson with its mass around 125 GeV by the ATLAS and CMS Collaborations marked the beginning of a new era in high energy physics.The Higgs boson will be the subject of extensive studies of the ongoing LHC program.At the same time,lepton collider based Higgs factories have been proposed as a possible next step beyond the LHC,with its main goal to precisely measure the properties of the Higgs boson and probe potential new physics associated with the Higgs boson.The Circular Electron Positron Collider(CEPC)is one of such proposed Higgs factories.The CEPC is an e^+e^- circular collider proposed by and to be hosted in China.Located in a tunnel of approximately 100 km in circumference,it will operate at a center-of-mass energy of 240 GeV as the Higgs factory.In this paper,we present the first estimates on the precision of the Higgs boson property measurements achievable at the CEPC and discuss implications of these measurements.展开更多
基金Supported by the IHEP Innovative Project on Sciences and Technologies (E2545AU210)。
文摘This paper presents the prospects of measuring σ(e^(+)e^(-)→ZH)× Br(H→γγ) in three Z decay channels Z→qq/μ^(+)μ^(-)/vv using the baseline detector with √s=240GeV at the Circular Electron Positron Collider(CEPC).Simulated Monte Carlo events were generated and scaled to an integrated luminosity of 5.6 ab^(-1) to mimic the data.Extrapolated results to 20 ab^(-1) are also reported.The expected statistical precision of these measurements after combining three channels of Z boson decay was 7.7%.With some preliminary estimation on the systematical uncertainties,the total precision is 7.9%.The performance of the CEPC electro-magnetic calorimeter(ECAL) was studied by smearing the photon energy resolution in simulated events in the e^(+)e^(-)→ZH→qqγγ channel.In the present ECAL design,the stochastic term in resolution plays the dominant role in the precision of Higgs measurements in the H→γγ channel.The impact of the resolution on the measured precision of σ(ZH)×Br(ZH→qqγγ) as well as the optimization of the ECAL constant and stochastic terms were studied for further detector design.
基金Supported by the National Key Program for S&T Researh and Development(2016YFA0400400)CAS Center for Excellence in Particle Physics+12 种基金Yifang Wang’s Science Studio of the Ten Thousand Talents Projectthe CAS/SAFEA International Partnership Program for Creative Research Teams(H751S018S5)IHEP Innovation Grant(Y4545170Y2)Key Research Program of Frontier Sciences,CAS(XQYZDY-SSW-SLH002)Chinese Academy of Science Special Grant for Large Scientific Project(113111KYSB20170005)the National Natural Science Foundation of China(11675202)the Hundred Talent Programs of Chinese Academy of Science(Y3515540U1)the National 1000 Talents Program of ChinaFermi Research Alliance,LLC(DE-AC02-07CH11359)the NSF(PHY1620074)by the Maryland Center for Fundamental Physics(MCFP)Tsinghua University Initiative Scientific Research Programthe Beijing Municipal Science and Technology Commission project(Z181100004218003)
文摘The discovery of the Higgs boson with its mass around 125 GeV by the ATLAS and CMS Collaborations marked the beginning of a new era in high energy physics.The Higgs boson will be the subject of extensive studies of the ongoing LHC program.At the same time,lepton collider based Higgs factories have been proposed as a possible next step beyond the LHC,with its main goal to precisely measure the properties of the Higgs boson and probe potential new physics associated with the Higgs boson.The Circular Electron Positron Collider(CEPC)is one of such proposed Higgs factories.The CEPC is an e^+e^- circular collider proposed by and to be hosted in China.Located in a tunnel of approximately 100 km in circumference,it will operate at a center-of-mass energy of 240 GeV as the Higgs factory.In this paper,we present the first estimates on the precision of the Higgs boson property measurements achievable at the CEPC and discuss implications of these measurements.
