Same-sign tetralepton signature in type-II seesaw at lepton colliders
Same-sign tetralepton signature in type-II seesaw at lepton colliders
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DOI：
10.1088/1674-1137/ac2edl
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Zhao-xia Meng
中科院分区：
文献类型：
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作者：
Xu-hong Bai;Zhi-long Han;Yi Jin;Hong-lei Li;Zhao-xia Meng
The same-sign tetralepton signature via the mixing of neutral Higgs bosons and their cascade decays to charged Higgs bosons is a unique signal in the type-II seesaw model with the mass spectrum M_(A~0)≃ M_(H~0) >M_(H~±) >M_(H~±±).In this study,we investigate this signature at future lepton colliders,such as the ILC,CLIC,and MuC.Direct searches for doubly charged scalar H~(±±) at the LHC have excluded M_(H~(±±))< 350(870) GeV in the H~(±±) → W~±W~±(ℓ~±ℓ~±) decay mode.Therefore,we choose M_(A~0) = 400,600,1000,1500 GeV as our benchmark scenarios.Constrained by direct search,H~(±±) → W~±W~± is the only viable decay mode for M_(A~0) = 400 GeV at the √s= 1 TeV ILC.With an integrated luminosity L = 8 ab~(-1),the promising region,with approximately 150 signal events,corresponds to a narrow band in the range of 10~(-4) GeV ≲ v_∆ ≲ 10~(-2) GeV.Meanwhile,for M_(A~0) = 600 GeV at the √s = 1.5 TeV CLIC,approximately 10 signal events can be produced with L = 2.5 ab~(-1).For heavier triplet scalars M_(A~0) ≳ 870 GeV,although the H~(±±) → ℓ~±ℓ~± decay mode is allowed,the cascade decays are suppressed.A maximum event number ~16 can be obtained at approximately v_∆ ~4× 10~(-4) GeV and λ_4 ~0.26 for M_(A~0) = 1000 GeV with L = 5 ab~(-1) at the √s=3 TeV CLIC.Finally,we find that this signature is not promising for M_(A~0) = 1500 GeV at the √s = 6 TeV MuC.Based on the benchmark scenarios,we also study the observability of this signature.In the H~(±±) → W~±W~±(ℓ~±ℓ~±) mode,one can probe M_(A~0) ≲ 800(1160) GeV at future lepton colliders.
