Precision Higgs physics at the CEPC *

Abstract

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.

Analytic next-to-leading order calculation of energy-energy correlation in gluon-initiated Higgs decays

“…In our Pythia setup we consider the process e + e − → H → gg at √ s = m H and generate 5000 events, which, according to [113] roughly corresponds to what CEPC expects to collect in the H → gg decay channel over a data taking period of 7 years. The tiny size of the Higgs to electrons coupling is irrelevant here, as the Higgs EEC is obtained from the decay of the Higgs particle at rest and does not depend on its production mechanism.…”

Probing the charm Yukawa coupling at future e−p and e+e−Li1, Wang2, Wang3 et al. 2019Phys. Rev. D9040View full textAdd to dashboardCite

“…We expect real data from the detector in the future will help improve the accuracy of the results. More systematic studies are also needed to better constrain the precision of the charm Yukawa coupling determination [53].…”

“…The CEPC is expected to make an excellent measurement of the charm Yukawa coupling and constrain δy c to ∼2% [53]. In principle, the Higgs-charm Yukawa coupling could be probed in e þ e − collision through two modes: decay and direct production.…”

Precision inclusive Higgs physics at e+e− colliders with tracking detectors and without calorimetry

“…refs. [16,24]), and assumes comparable tracking technology as that envisioned for e.g. the International Linear Detector (ILD) [18,25].…”

“…Deviations in σ Zh can be tied to solutions to the hierarchy problem, dark matter, or new physics predicting a strong first-order electroweak phase transition [8][9][10][11][12][13][14]. Most proposals for future e + e − colliders ultimately aim to achieve (sub)percent-level precision in σ Zh [1,3,5,[15][16][17][18], which would provide unparalleled sensitivity to new physics involving the Higgs boson. It JHEP09(2020)174 Figure 1.…”