CEPC Z-pole polarization design studies

2021 ◽  
pp. 2142003
Author(s):  
Wenhao Xia ◽  
Jie Gao ◽  
Yiwei Wang ◽  
Dou Wang
Keyword(s):  
Beam Energy ◽  
Center Of Mass ◽  
Transverse Polarization ◽  
Beam Polarization ◽  
Energy Measurement ◽  
Design Studies ◽  
Electron Positron ◽  
Polarized Beam ◽  
Different Types ◽  
Schematic Design

In this paper, we give preliminary designs of beam polarization manipulations by inserting three different types of insertions in the Circular Electron–Positron Collider (CEPC) at center-of-mass energies of 91 GeV (Z-pole). With the wigglers in the collider ring, we can obtain 5% transverse polarization in 1.1 h for the precise energy measurement. To overcome depolarization effects as the beam energy rises from 10 GeV to 45.5 GeV in the booster ring, Siberian snakes based on helical magnets are adopted. Finally, for longitudinally polarized beam collisions, a schematic design of spin rotators based on solenoids in the collider ring is studied.

scholarly journals The measurement of the $$H\rightarrow \tau \tau $$ signal strength in the future $$e^{+}e^{-}$$ Higgs factories

2020 ◽  
Vol 80 (1) ◽  
Author(s):  
Dan Yu ◽  
Manqi Ruan ◽  
Vincent Boudry ◽  
Henri Videau ◽  
Jean-Claude Brient ◽  
...  
Keyword(s):  
Linear Collider ◽  
Simulation Analysis ◽  
Center Of Mass ◽  
International Linear Collider ◽  
Signal Strength ◽  
Relative Accuracy ◽  
Hadronic Decay ◽  
Beam Polarization ◽  
Baseline Design ◽  
Electron Positron

AbstractThe Circular Electron Positron Collider and the International Linear Collider are two electron-positron Higgs factories. They are designed to operate at a center-of-mass energy of 240 and 250 GeV and accumulate 5.6 and 2 $$ab^{-1}$$ab-1 of integrated luminosity. This paper estimates their performance on the $$H \rightarrow \tau ^{+}\tau ^{-}$$H→τ+τ- benchmark measurement. Using the full simulation analysis, the CEPC is expected to measure the signal strength to a relative accuracy of 0.8%. Extrapolating to the ILC setup, we conclude the ILC can reach a relative accuracy of 1.1% or 1.2%, corresponding to two benchmark beam polarization setups. The physics requirement on the mass resolution of the Higgs boson with hadronic decay final states is also discussed, showing that the CEPC baseline design and reconstruction fulfill the accuracy requirement of the $$H\rightarrow \tau ^{+}\tau ^{-}$$H→τ+τ- signal strength.

The beam energy measurement system for the Beijing electron-positron collider

2012 ◽  
Vol 225-227 ◽  
pp. 309-314 ◽  
Author(s):  
J.Y. Zhang ◽  
E.V. Abakumova ◽  
M.N. Achasov ◽  
V.E. Blinov ◽  
X. Cai ◽  
...  
Keyword(s):  
Measurement System ◽  
Beam Energy ◽  
Energy Measurement ◽  
Electron Positron

The circular electron–positron collider beam energy measurement with Compton scattering and beam tracking method

2020 ◽  
Vol 91 (3) ◽  
pp. 033109
Author(s):  
Guangyi Tang ◽  
Shanhong Chen ◽  
Yuan Chen ◽  
Zhe Duan ◽  
Manqi Ruan ◽  
...  
Keyword(s):  
Compton Scattering ◽  
Beam Energy ◽  
Energy Measurement ◽  
Tracking Method ◽  
Electron Positron ◽  
Beam Tracking

scholarly journals Circular electron-positron collider beam energy measurement scheme based on microwave-electronic Compton backscattering

2021 ◽  
Vol 70 (13) ◽  
pp. 131301-131301
Author(s):  
Dong Xu ◽  
◽  
Huang Yong-Sheng ◽  
Tang Guang-Yi ◽  
Chen Shan-Hong ◽  
...  
Keyword(s):  
Beam Energy ◽  
Energy Measurement ◽  
Measurement Scheme ◽  
Electron Positron ◽  
Compton Backscattering ◽  
Microwave Electronic

scholarly journals Probe of the Anomalous Quartic Couplings with Beam Polarization at the CLIC

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
A. Senol ◽  
M. Köksal ◽  
S. C. İnan
Keyword(s):  
Confidence Level ◽  
Semileptonic Decay ◽  
Linear Collider ◽  
Decay Channel ◽  
Center Of Mass ◽  
Positron Beam ◽  
Beam Polarization ◽  
Electron Positron ◽  
Integrated Luminosity

We have investigated the anomalous quartic couplings defined by the dimension-8 operators in semileptonic decay channel of thee+e-→νeW-W+ν-eprocess for unpolarized and polarized electron (positron) beam at the Compact Linear Collider. We give the 95% confidence level bounds on the anomalousfS0/Λ4,fS1/Λ4, andfT0/Λ4couplings for various values of the integrated luminosities and center-of-mass energies. The best sensitivities obtained on anomalousfS0/Λ4,fS1/Λ4, andfT0/Λ4couplings through the processe+e-→νeW-W+ν-ewith beam polarization ats=3 TeV and an integrated luminosity ofLint=2000 fb-1are[-4.05;3.67]×10-12 GeV-4,[-3.08;2.12]×10-12 GeV-4, and[-1.98;0.64]×10-13 GeV-4, which show improvement over the current bounds.

scholarly journals Indirect measurement of triple-Higgs coupling at an electron–positron collider with polarized beams

2020 ◽  
Vol 35 (04) ◽  
pp. 2050011
Author(s):  
Saurabh D. Rindani ◽  
Balbeer Singh
Keyword(s):  
Center Of Mass ◽  
Indirect Measurement ◽  
Higgs Production ◽  
Beam Polarization ◽  
Higgs Coupling ◽  
Mass Energy ◽  
Polarized Beams ◽  
Center Of Mass Energy ◽  
Electron Positron ◽  
Dominant Process

We examine the possibility of using single-Higgs production at an [Formula: see text] collider with polarized beams to measure, or constrain, indirectly a possible anomalous triple-Higgs coupling, which can contribute to the process via one-loop diagrams. In the dominant process [Formula: see text], longitudinally polarized beams can lead to an improvement in the cross-section by 50% for [Formula: see text] and [Formula: see text] polarizations of [Formula: see text] and [Formula: see text], respectively. This corresponds to an improvement in the sensitivity to the triple-Higgs coupling of about 18% for a center-of-mass energy of 250 GeV and an integrated luminosity of 2 ab[Formula: see text], making a strong case of beam polarization. This also implies that with polarized beams, the luminosity needed to get a particular sensitivity is less by about 33% as compared to that needed with unpolarized beams. Even when only the [Formula: see text] beam is polarized [Formula: see text], the improvement in the sensitivity is about 8%. We also study the effect of longitudinal beam polarization on the sensitivity to the triple-Higgs coupling of Higgs production through the subdominant process [Formula: see text] occurring through [Formula: see text] fusion.

CEPC booster design study

2017 ◽  
Vol 32 (34) ◽  
pp. 1746009
Author(s):  
Tianjian Bian ◽  
Jie Gao ◽  
Chuang Zhang ◽  
Xiao-Hao Cui ◽  
Yi-Wei Wang ◽  
...  
Keyword(s):  
Beam Energy ◽  
Center Of Mass ◽  
High Energy ◽  
Low Energy ◽  
Mass Energy ◽  
Dipole Magnet ◽  
Center Of Mass Energy ◽  
The Earth ◽  
Electron Positron ◽  
Normal Ring

In September 2012, Chinese scientists proposed a Circular Electron Positron Collider (CEPC) in China at 240 GeV center-of-mass energy for Higgs studies. The booster provides 120 GeV electron and positron beams to the CEPC collider for top-up injection at 0.1 Hz. The design of the full energy booster ring of the CEPC is a challenge. The ejected beam energy is 120 GeV and the injected beam energy is 6 GeV. In this paper we describe two alternative schemes, the wiggler bend scheme and the normal bend scheme. For the wiggler bend scheme, we propose to operate the booster ring as a large wiggler at low energy and as a normal ring at high energy to avoid the problem of very low dipole magnet fields. For the normal bend scheme, we implement the orbit correction to correct the earth field.

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