Large Neutrino "Collider"

Abstract

We propose using current and future large-volume neutrino telescopes as ``Large Neutrino Colliders" (L$ν$Cs) to explore TeV-scale physics beyond the Standard Model. Cosmic neutrinos with energies above 100 PeV colliding with nucleons in the detector reach center-of-mass energies beyond the 14 TeV limit of the Large Hadron Collider (LHC). Using recently predicted and measured high-energy and ultra-high-energy neutrino fluxes from IceCube and KM3NeT, we estimate mass-scale sensitivities for representative new physics scenarios at 1--30 km$^3$ L$ν$Cs. Our results demonstrate that L$ν$Cs provide a novel avenue to probe multi-TeV particles with sensitivities comparable to, or even surpassing, those of the LHC.

Figures (18)

• Figure 1: Projected mass-scale reaches at different lepton-hadron L$\nu$C configurations, compared with those at the LHC and HL-LHC. The analysis in this study includes both starting and throughgoing muon tracks.
• Figure 2: The high-energy (HE) and ultra-high-energy (UHE) neutrino fluxes (for $\nu_\mu + \bar{\nu}_\mu$) used in this work, including three main components: the atmospheric flux dominant below $\sim 10^5$ GeV nuflux:2024, the astrophysical flux measured by IceCube with a power-law spectrum IceCube:2024fxo, and an UHE component motivated by the recent KM3NeT measurement KM3NeT:2025npi. The total flux is shown as the solid blue curve. See text and Appendix \ref{['app:flux']} for details on the models and uncertainties. The upper horizontal axis indicates the COM energy, $\sqrt{s} \approx \sqrt{2m_p E_\nu}$, while the right vertical axis shows the product of $E_\nu$ and the L$\nu$C luminosity $L$, assuming a 10 km$^3$ detector volume and a 10-year observation period.
• Figure 3: Tree-level production cross sections for neutrinogluon ($\nu_8$) from neutrino–nucleon scattering, which are identical for neutrinos and antineutrinos, followed by the decay $\nu_8 \to \mu_8^- W^+$ (with $\mu_8^-\to \mu^- g$). We present the results from two calculations: using the full $\nu_8$ propagator (dashed lines) and using the narrow-width approximation (NWA; solid lines). For comparison, the SM background cross sections of CCDIS and NCDIS of neutrinos and antineutrinos are also shown, as labeled.
• Figure 4: Our projected sensitivities for the leptogluon model using starting and throughgoing track events in neutrino telescopes with volumes of 1, 8, and 30 km$^3$, respectively, and 20 years of observation. As a comparison, we also show the sensitivity in the dashed lines for the LHC with an integrated luminosity of 139 fb$^{-1}$Almeida:2022udp and the projected one based on the HL-LHC with 3 ab$^{-1}$Almeida:2022udpZurbanoFernandez:2020cco. The gray dotted line is the guided effective-field-theory lower bound for $\Lambda/a > M_{\mu_8}/3$.
• Figure 5: Upper: The dependence of neutrino-nucleon scattering cross sections on the four-fermion contact operators with a fixed neutrino incident energy $E_\nu=1\cdot10^{6}~\textrm{GeV}$. Here, the dots with labels are calculated with FeynCalcShtabovenko:2020gxv/FormCalcHahn:2016ebn interfacing ManeParse (MP) Clark:2016jgm, MadGraph (MG) Alwall:2014hca, and Whizard (WH) Kilian:2007gr, respectively. The lines are interpolated or extrapolated with Eq. (\ref{['eq:WCxs']}). Lower: The cross-section dependence on the neutrino energy, by fixing SMEFT operators with a few representative coefficient values. The growing features of the lower panels are due to the violation of the EFT, but in our actual limits we did ensure that the parton-level COM energy is smaller than around the cutoff scale or $\Lambda\gtrsim\sqrt{\hat{s}}/3(4)$ (see Fig. \ref{['fig:XSRatio']}).