[논문 리뷰] Tests of the Standard Model at the International Linear Collider

H. Fujii, Christophe Grojean외 20명|arXiv (Cornell University)|2019. 08. 29.

Particle physics theoretical and experimental studies참고 문헌 50인용 수 57

한 줄 요약

본 논문은 ILC가 표준 모델에 대한 고정밀 테스트를 어떻게 수행할 수 있는지 조사합니다. 정밀 전기약 측정, SMEFT 힉스 적합, 힉스 자기결합, 그리고 여러 에너지 단계에 걸친 상/하 쿼크 연구를 포함합니다.

ABSTRACT

We present an overview of the capabilities that the International Linear Collider (ILC) offers for precision measurements that probe the Standard Model. First, we discuss the improvements that the ILC will make in precision electroweak observables, both from W boson production and radiative return to the Z at 250 GeV in the center of mass and from a dedicated GigaZ stage of running at the Z pole. We then present new results on precision measurements of fermion pair production, including the production of b and t quarks. We update the ILC projections for the determination of Higgs boson couplings through a Standard Model Effective Field Theory fit taking into account the new information on precision electroweak constraints. Finally, we review the capabilities of the ILC to measure the Higgs boson self-coupling.

연구 동기 및 목표

• Assess how the ILC improves precision electroweak observables via W production, Z-pole running (GigaZ), and radiative return to Z at 250 GeV.
• Update Higgs coupling projections using SMEFT fits with refined electroweak constraints.
• Evaluate capabilities for Higgs self-coupling measurement and top/bottom quark pair production for SMEFT interpretations.
• Outline ILC run plan, beam polarization/energy measurement strategies, and their impact on systematic uncertainties.
• Provide quantified projections for precision measurements across ILC250, ILC350, ILC500, GigaZ, and ILC1000 stages.

제안 방법

• Describe the staged ILC run plan and integrated luminosities at each energy (250, 350, 500 GeV, plus 1 TeV and GigaZ).
• Detail precision requirements and measurement strategies for beam polarization, beam energy, and luminosity.
• Present SMEFT-based Higgs coupling fits using observables from fermion pair production, Higgs production, and precision electroweak data.
• Analyze W mass and width extraction methods from WW events and leptonic/hadronic decays, including systematic uncertainties.
• Incorporate radiative-return Z measurements and GigaZ data to sharpen electroweak constraints and SMEFT fits.
• Discuss top/bottom quark pair production as SMEFT probes and their impact on Yukawa and EW couplings.]
• research_questions.0
• What precision can the ILC achieve for W boson properties (mass, width) and how do systematic errors dominate at each stage?
• How can SMEFT coefficients be constrained by a global fit to ILC observables including Higgs, EW, and fermion-pair processes?
• What is the projected precision on Higgs couplings and self-coupling at various ILC energies, and how does GigaZ improve them?
• How effectively can ILC measurements disentangle top and bottom quark operator effects in SMEFT?
• What are the roles of beam polarization, energy calibration, and luminosity in realizing these precision targets?

실험 결과

연구 질문

• RQ1 What precision can the ILC achieve for W boson properties (mass, width) and how do systematic errors dominate at each stage?
• RQ2 How can SMEFT coefficients be constrained by a global fit to ILC observables including Higgs, EW, and fermion-pair processes?
• RQ3 What is the projected precision on Higgs couplings and self-coupling at various ILC energies, and how does GigaZ improve them?
• RQ4 How effectively can ILC measurements disentangle top and bottom quark operator effects in SMEFT?
• RQ5 What are the roles of beam polarization, energy calibration, and luminosity in realizing these precision targets?

주요 결과

• ILC250 with >10^7 W bosons yields m_W ~ 1.1 MeV statistical uncertainty and Γ_W ~ 3.2 MeV under specified mass resolutions.
• Beam polarisation and energy measurements can reach sub-permille level control, enabling high-precision left-right asymmetry and EW observables.
• SMEFT fits at ILC can push Higgs coupling uncertainties below the 1% level across 250–1000 GeV stages, especially when incorporating GigaZ constraints.
• Higgs self-coupling can be probed directly via double Higgs production at 500 GeV and 1 TeV, with a precision better than 10% when combining measurements.
• Radiative return to the Z and GigaZ running substantially improve precision electroweak constraints, informing SMEFT analyses and Z-fermion coupling measurements.
• ILC’s polarized-beam program allows independent measurement of SMEFT coefficients in four-fermion and fermion-pair processes, offering model-independent determinations.