Heavy Neutrino Searches via Same-sign Lepton Pairs at the Higgs Factory

Abstract

This paper investigates the $e^{-}{e}^{+}\to Z{h}_1$ sensitivity for Higgs boson's rare decay into heavy neutrinos $h_1\to NN$ at the proposed electron-positron collider, with the focus on multi-lepton final states that contain same-sign lepton pairs. $h_1\to NN$ decay can derive from Higgs boson's mixing with new physics scalar(s) that is complementary to the contribution from active-sterile neutrino mixings. We consider the scenario with a singlet scalar which gives the heavy neutrino mass and has a small mixing with the SM Higgs boson. We analyze the semileptonic, fully leptonic and mixed $NN$ decay scenarios, and categorize the signal on the number of leptons in the final state: ${\ell }^{\pm }{\ell }^{\pm }$ with at least 3 jets, ${\ell }^{\pm }{\ell }^{\pm }\ell$ with at least 2 jets, and $e^{\pm }{e}^{\pm }{\mu }^{\mp }{\mu }^{\mp }$ plus with at least 1 jet, each containing one or two same-sign dilepton system(s). Selection cuts are optimized for the presence of the associated $Z$-boson, which leads to additional backgrounds at the $e^{-}{e}^{+}$ collider. The Standard Model background channels are systematically analyzed. Sensitivity limits on $h_1\to NN$ branching fractions are derived for signals with 2-4 final leptons assuming the heavy neutrino masses are between 10 and 60 GeV. With 240 GeV center-of-mass energy and 5.6 ab${}^{-1}$ design luminosity, $h_1\to NN$ branching fraction can be probed to $2\times 10^{-4}$ in $2\ell$ and $3\ell$ channels, and $6\times 10^{-4}$ in the $4\ell$ channel at $95\%$ confidence level. $3\ell ,4\ell$ channels expect one or fewer background event, and their sensitivities saturate the statistic limit at 5.6 ab${}^{-1}$ luminosity. A same-sign trilepton (${\ell }^{\pm }{\ell }^{\pm }{\ell }^{\pm }$) signal in the $3\ell$ channel is also discussed. Our search strategy provides an approach to discovering the singlet scalar and exploring the origin of neutrino masses at future $e^{-}{e}^{+}$ colliders.

arXiv comment10 pages, 6 figures, 3 tables, add some comments

References in corpus (51)

• PYTHIA 6.4 Physics and Manual
• PYTHIA 6.2 Physics and Manual
• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• A Brief Introduction to PYTHIA 8.1
• DELPHES 3, A modular framework for fast simulation of a generic collider experiment
• FeynRules 2.0 - A complete toolbox for tree-level phenomenology
• UFO - The Universal FeynRules Output
• The Physics of Heavy Z' Gauge Bosons
• The Search for Heavy Majorana Neutrinos
• Neutrinos and Collider Physics
• Sterile neutrino searches at future $e^{-}{e}^{+}$, $pp$, and $e^{-}p$ colliders
• Search for heavy neutral leptons in events with three charged leptons in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Search for new resonances in mass distributions of jet pairs using 139 fb${}^{-1}$ of $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Testing sterile neutrino extensions of the Standard Model at future lepton colliders
• Search for diphoton resonances in the mass range from 150 to 850 GeV in pp collisions at sqrt(s) = 8 TeV
• Search for heavy neutral leptons in decays of $W$ bosons produced in 13 TeV $pp$ collisions using prompt and displaced signatures with the ATLAS detector
• Search for high-mass resonances in dilepton final states in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Prospects of Heavy Neutrino Searches at Future Lepton Colliders
• Higgs boson potential at colliders: status and perspectives
• Displaced vertex searches for sterile neutrinos at future lepton colliders
• Search for a standard model-like Higgs boson in the mass range between 70 and 110 GeV in the diphoton final state in proton-proton collisions at $\sqrt{s}=$ 8 and 13 TeV
• Lepton Number Violation in Higgs Decay at LHC
• Indirect searches for sterile neutrinos at a high-luminosity Z-factory
• Improving Electro-Weak Fits with TeV-scale Sterile Neutrinos
• The seesaw portal in testable models of neutrino masses
• Long-lived Heavy Neutrinos from Higgs Decays
• Search for heavy Majorana neutrinos in same-sign dilepton channels in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Invisible Higgs Boson Decay into Massive Neutrinos of 4th Generation
• Constraining Sterile Neutrinos from Precision Higgs Data
• Majorana Higgses at colliders
• Broadening the Higgs Boson with Right-Handed Neutrinos and a Higher Dimension Operator at the Electroweak Scale
• LHC Constraints on a $B-L$ Gauge Model using Contur
• Maxi-sizing the trilinear Higgs self-coupling: how large could it be?
• Heavy Neutrino Search via the Higgs boson at the LHC
• Searching for a Sterile Neutrino in Tau Decays at B-factories
• Physics with Far Detectors at Future Lepton Colliders
• Lepton number violation by heavy Majorana neutrino in $B$ decays
• Lepton Flavor Violating Dilepton Dijet Signatures from Sterile Neutrinos at Proton Colliders
• The see-saw portal at future Higgs Factories
• Collider signatures of sterile neutrinos in models with a gauge-singlet Higgs
• Search for heavy neutral leptons in $W^{+}\to {\mu }^{+}{\mu }^{\pm }\text{jet}$ decays
• A Bayesian analysis of sneutrino DM in the NMSSM with Type-I seesaw mechanism
• Signatures of Dirac and Majorana Sterile Neutrinos in Trilepton Events at the LHC
• Heavy neutrino searches at future $Z$-factories
• Signature of heavy sterile neutrinos at CEPC
• Z-Boson Decays into Majorana or Dirac (Heavy) Neutrinos
• Dark matter indirect detection signals and the nature of neutrinos in the supersymmetric $U(1{)}_{B-L}$ extension of the standard model
• Probing the Decoupled Seesaw Scalar in Rare Higgs Decay
• A potential scenario for the Majorana neutrino detection at future lepton colliders
• Lepton number violation in heavy Higgs decays to sneutrinos
• $W^{+}{W}^{-}H$ Production at Lepton Colliders: A New Hope for Heavy Neutral Leptons

Cited by in corpus (5)

• Heavy Majorana neutrino pair production from $Z^{\prime }$ at hadron and lepton colliders
• Testing electroweak scale seesaw models at $e^{-}\gamma$ and $\gamma \gamma$ colliders
• Search for heavy Majorana neutrinos in the $\tau$ final state at proton-electron colliders
• Probe the Mixing Parameter $|V_{\tau N}{|}^2$ for Heavy Neutrinos
• Riding the Seesaw: What Higgsstrahlung May Reveal about Massive Neutrinos