Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2408.01389

Discovering heavy neutrino-antineutrino oscillations at the $Z$-pole

Stefan Antusch·Jan Hajer·Bruno M. S. Oliveira
View original source ↗Read source document ↗Export metadata ↓

Abstract

Collider-testable type I seesaw extensions of the Standard Model are generally protected by an approximate lepton number (LN) symmetry. Consequently, they predict pseudo-Dirac heavy neutral leptons (HNLs) composed of two nearly degenerate Majorana fields. The interference between the two mass eigenstates can induce heavy neutrino-antineutrino oscillations (NNOs) leading to observable lepton number violation (LNV), even though the LN symmetry is approximately conserved. These NNOs could be resolved in long-lived HNL searches at collider experiments, such as the proposed Future Circular $e^+e^-$ Collider (FCC-$ee$) or Circular Electron Positron Collider (CEPC). However, during their $Z$-pole runs, the LN carried away by the light (anti)neutrinos produced alongside the HNLs prevents LNV from being observed directly. Nevertheless, NNOs materialise as oscillating signatures in final state distributions. We discuss and compare a selection of such oscillating observables, and perform a Monte Carlo simulation to assess the parameter space in which NNOs could be resolved.

Explore related subjects

hep-phhep-ex

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Stefan Antusch, Jan Hajer, Bruno M. S. Oliveira. 2024-08-02. Discovering heavy neutrino-antineutrino oscillations at the $Z$-pole. https://arxiv.org/abs/2408.01389

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Exploring the Singlino-dominated Thermal Neutralino Dark Matter in the $Z_3$ invariant NMSSM

We examine the parameter space of the Next to Minimal Supersymmetric Standard Model (NMSSM) with Singlino-dominated neutralino $\widetildeχ_1^0$ as the lightest supersymmetric particle (LSP). Our study focuses on identifying the regions within this parameter space that produce a thermal relic abundance of $\widetildeχ_1^0$ smaller than the observed cold dark matter relic density while remaining consistent with constraints from LEP measurements, low-energy experiments, Higgs measurements, LHC data, and dark matter direct detection experiments. We identify the dominant annihilation modes of the LSP neutralino across varying LSP mass ranges $\sim \mathcal{O}(1)-\mathcal{O}(10^{3})~$GeV. Furthermore, we conduct a benchmark study to assess the production rates of triple-boson final states emerging from direct electroweakino pair production at the LHC. Drawing insights from these findings, we perform a detailed collider analysis to explore the future potential of probing the triple-boson final states involving a light Higgs boson at the high-luminosity LHC (HL-LHC).

hep-ph↗
arXiv2026

Unveiling the Collins-Soper kernel in inclusive DIS at threshold

We revisit the factorization of inclusive deep inelastic scattering (DIS) near the kinematic threshold in terms of collinear, off-light-cone operators. At threshold, particle production develops around two opposite near-light-cone directions in close analogy with transverse-momentum-dependent semi-inclusive DIS. The Collins-Soper kernel then emerges as the universal function governing the rapidity evolution of the relevant parton correlators in both cases. Our new framework also clarifies outstanding issues related to soft radiation and rapidity divergences at threshold.

hep-ph↗
arXiv2026

Novel Light Dark Matter Detection with Quantum Parity Detector Using Qubit Arrays

We present the design and the sensitivity reach of the Qubit-based Light Dark Matter detection experiment. We propose the novel two-chip design to reduce signal dissipation, with quantum parity measurement to enhance single-phonon detection sensitivity. We demonstrate the performance of the detector with full phonon and quasiparticle simulations. The experiment is projected to detect $\gtrsim 30$ meV energy deposition with nearly $100\%$ efficiency and high energy resolution. The sensitivity to $m_χ\gtrsim 0.01$ MeV dark matter scattering cross section is expected to be advanced by orders of magnitude for both light and heavy mediators, and similar improvements will be achieved for axion and dark photon absorption in the $0.04$-$0.2$ eV mass range.

hep-ph↗