Excess of Tau events at SND@LHC, FASER$\nu$ and FASER$\nu$2

Abstract

During the run III of the LHC, the forward experiments FASER$\nu$ and SND@LHC will be able to detect the Charged Current (CC) interactions of the high energy neutrinos of all three flavors produced at the ATLAS Interaction Point (IP). This opportunity may unravel mysteries of the third generation leptons. We build three models that can lead to a tau excess at these detectors through the following Lepton Flavor Violating (LFV) beyond Standard Model (SM) processes: (1) ${\pi }^{+}\to {\mu }^{+}{\nu }_{\tau }$; (2) ${\pi }^{+}\to {\mu }^{+}{\bar{\nu }}_{\tau }$ and (3) ${\nu }_e+\mathrm{nucleus}\to \tau +X$. We comment on the possibility of solving the $(g-2{)}_{\mu }$ anomaly and the $\tau$ decay anomalies within these models. We study the potential of the forward experiments to discover the $\tau$ excess or to constrain these models in case of no excess. We then compare the reach of the forward experiments with that of the previous as well as next generation experiments such as DUNE. We also discuss how the upgrade of FASER$\nu$ can distinguish between these models by studying the energy spectrum of the tau.

References in corpus (35)

• The anomalous magnetic moment of the muon in the Standard Model
• Reevaluation of the Hadronic Contributions to the Muon g-2 and to alpha(MZ)
• Reevaluation of the hadronic vacuum polarisation contributions to the Standard Model predictions of the muon g-2 and alpha(mZ) using newest hadronic cross-section data
• A new evaluation of the hadronic vacuum polarisation contributions to the muon anomalous magnetic moment and to $\mathbf{\alpha }({\mathbf{m}}_{\mathbf{Z}}^2)$
• Update of the global electroweak fit and constraints on two-Higgs-doublet models
• General bounds on non-standard neutrino interactions
• A Tale of Two Anomalies
• A model for large non-standard interactions of neutrinos leading to the LMA-Dark solution
• Lepton Flavor Violating Non-Standard Interactions via Light Mediators
• Neutrinophilic Non-Standard Interactions
• Anomalous Magnetic Moments from Asymptotic Safety
• Hadronic tau decays as New Physics probes in the LHC era
• White Paper on New Opportunities at the Next-Generation Neutrino Experiments (Part 1: BSM Neutrino Physics and Dark Matter)
• Forward Neutrino Fluxes at the LHC
• A combined study of source, detector and matter non-standard neutrino interactions at DUNE
• Detecting Dark Matter with Far-Forward Emulsion and Liquid Argon Detectors at the LHC
• Searching for Lepton Flavour (Universality) Violation and Collider Signals from a Singly-Charged Scalar Singlet
• Model Building from Asymptotic Safety with Higgs and Flavor Portals
• Neutral Current Neutrino Interactions at FASER$\nu$
• EFT at FASER$\nu$
• A Sterile Neutrino Origin for the Upward Directed Cosmic Ray Showers Detected by ANITA
• Far-forward neutrinos at the Large Hadron Collider
• Probing Light Gauge Bosons in Tau Neutrino Experiments
• Neutrino beam-dump experiment with FASER at the LHC
• Rho-meson form factors and QCD sum rules
• A model for lepton flavor violating non-standard neutrino interactions
• Possible tau appearance experiment with atmospheric neutrinos
• Further studies on the physics potential of an experiment using LHC neutrinos
• Discovery potential of FASER$\nu$ with contained vertex and through-going events
• Tau Neutrino Identification in Atmospheric Neutrino Oscillations Without Particle Identification or Unitarity
• Probing Source and Detector NSI parameters at the DUNE Near Detector
• SLIM at LHC: LHC search power for a model linking dark matter and neutrino mass
• Unravelling the richness of dark sector by FASER$\nu$
• On the Tau flavor of the cosmic neutrino flux
• Observability of Light Charged Higgs Decay to Muon in Top Quark Pair Events at LHC