Probing the Higgs with angular observables at future e⁺e^– colliders

Journal Article · 24 October 2016 · International Journal of Modern Physics A

DOI: https://doi.org/10.1142/S0217751X1644005X · OSTI ID:1358111

Liu, Zhen ^[1]

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1. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States). Theoretical Physics Dept.

In this paper, I summarize our recent works on using differential observables to explore the physics potential of future e⁺e^– colliders in the framework of Higgs effective field theory. This proceeding is based upon Refs. 1 and 2. We study angular observables in the e⁺e^– → ZHℓ⁺ℓ^–b$$\bar{b}$$ channel at future circular e⁺e^– colliders such as CEPC and FCC-ee. Taking into account the impact of realistic cut acceptance and detector effects, we forecast the precision of six angular asymmetries at CEPC (FCC-ee) with center-of-mass energy √s = 240 GeV and 5 (30) ab^–1 integrated luminosity. We then determine the projected sensitivity to a range of operators relevant for the Higgsstrahlung process in the dimension-6 Higgs EFT. Our results show that angular observables provide complementary sensitivity to rate measurements when constraining various tensor structures arising from new physics. We further find that angular asymmetries provide a novel means of constraining the “blind spot” in indirect limits on supersymmetric scalar top partners. Finally, we also discuss the possibility of using ZZ-fusion at e⁺e^– machines at different energies to probe new operators.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-07CH11359
• OSTI ID: 1358111
• Report Number(s): FERMILAB-CONF-16-681-T; 1501170
• Journal Information: International Journal of Modern Physics A, Vol. 31, Issue 33; ISSN 0217-751X
• Publisher: World ScientificCopyright Statement
• Country of Publication: United States
• Language: English