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

Area of Science:

• Particle Physics
• Accelerator Physics
• Metrology

Background:

• Precise measurement of Higgs, W, and Z boson masses requires sub-MeV beam energy accuracy at colliders.
• Current methods face limitations in achieving the necessary precision for future collider upgrades.

Purpose of the Study:

• To develop and validate a novel method for precise beam energy measurement at a circular electron-positron collider.
• To reduce the uncertainty in Higgs/W/Z boson mass measurements by improving beam energy determination.

Main Methods:

• Utilizing inverse Compton scattering between a lepton bunch and an Yttrium-Aluminum-Garnet laser pulse.
• Analyzing the deflection of scattered and main beams in a precisely calibrated magnetic field.
• Detecting beam deflections with micron-level spatial resolution.

Main Results:

• Achieved a beam energy uncertainty of approximately 2 MeV in the Higgs mode.
• Detailed analysis of systematic uncertainties including detector alignment, magnetic field, beam angle, and synchrotron radiation.
• Monte Carlo simulations confirmed statistical error estimations.

Conclusions:

• The developed method provides a precise and applicable technique for beam energy measurement in circular electron-positron colliders.
• This technique is adaptable to various collider operating modes, enhancing its utility.
• The achieved precision contributes significantly to reducing uncertainties in fundamental particle mass measurements.