Deep inelastic $e-\tau$ and $\mu -\tau$ conversion in the NA64 experiment at the CERN SPS

Abstract

We study the Lepton Flavor Violating (LFV) $e(\mu )-\tau$ conversion in Deep Inelastic Scattering (DIS) of electron (muon) on fixed-target nuclei. Our model-independent analysis is based on the set of the low-energy effective four-fermion LFV operators composed of leptons and quarks with the corresponding mass scales ${\Lambda }_k$ for each operator. Using the estimated sensitivity of the search for this LFV process in events with large missing energy in the NA64 experiment at the CERN SPS, we derive lower limits for ${\Lambda }_k$ and compared them with the corresponding limits existing in the literature. We show that the DIS $e(\mu )-\tau$ conversion is able to provide a plenty of new limits as yet non-existing in the literature. We also analyzed the energy spectrum of the final-state $\tau$ and discussed viability of the observation of this process in the NA64 experiment and ones akin to it. The case of polarized beams and targets is also discussed.

arXiv comment18 pages

References in corpus (28)

• Implications of CTEQ global analysis for collider observables
• The CT10 NNLO Global Analysis of QCD
• Anatomy and Phenomenology of mu-tau Lepton Flavour Violation in the MSSM
• Search for invisible decays of sub-GeV dark photons in missing-energy events at the CERN SPS
• On the model discriminating power of mu -> e conversion in nuclei
• Search for vector mediator of Dark Matter production in invisible decay mode
• τ- μFlavor Violation as a Probe of the Scale of New Physics
• Muon-electron conversion in strange quark sea
• Higgs-Mediated e -> mu transitions in II Higgs doublet Model and Supersymmetry
• Exotic muon-electron conversion in nuclei and R-parity violating supersymmetry
• Polarized deep inelastic scattering at high energies and parity violating structure functions
• In-flight cLFV conversion: $e-\mu$, $e-\tau$ and $\mu -\tau$ in minimal extensions of the Standard Model with sterile fermions
• Electron-to-Tau Lepton Flavor Violation at the Electron-Ion Collider
• New bounds on lepton flavor violating decays of vector mesons and the Z0 boson
• Mu + N --> Tau + N at a Muon or Neutrino Factory
• B-quark mediated neutrinoless ${\mu }^{-}-e^{-}$ conversion in presence of R-parity violation
• A Study of Lepton Flavor Violating $\mu N(eN)\to \tau X$ Reactions in Supersymmetric Models
• Probing lepton flavour violation in ${\nu }_{\mu }+N\to \tau +...$ scattering and $\mu \to tau$ conversion on nucleons
• Lepton flavor violating decays of vector mesons
• Scalar meson mediated nuclear mu-e conversion
• Neutrino mediated muon--electron conversion in nuclei revisited
• Effective Lagrangian approach to nuclear mu-e conversion and the role of vector mesons
• Vector mesons in nuclear mu-e conversion
• Higgs mediated CLFV processes $\mu N(eN)\to \tau X$ via gluon operators
• The (muon^-,muon^+) conversion in nuclei as a probe of new physics
• Limits on Lepton Flavor Violation from μ-e-conversion
• Search for lepton-flavor violation in e+p collisions at HERA
• Analysis of mu-tau conversion through μN -> τX deep inelastic scattering induced by unparticles

Cited by in corpus (17)

• Physics Beyond Colliders at CERN: Beyond the Standard Model Working Group Report
• Charged Lepton Flavor Violation at the EIC
• Prospects in the search for a new light $Z^{\prime }$ boson with the NA64$\mu$ experiment at the CERN SPS
• Lepton-flavour violation in hadronic tau decays and $\mu -\tau$ conversion in nuclei
• Lepton-Flavor-Violating ALP Signals with TeV-Scale Muon Beams
• Constraints on leptoquarks from lepton-flavour-violating tau-lepton processes
• Lepton Phenomenology of Stueckelberg Portal to Dark Sector
• Sensitivity potential to a light flavor-changing scalar boson with DUNE and NA64$\mu$
• Lepton Flavor Violation from diphoton effective interactions
• Bounds on lepton flavor violating physics and decays of neutral mesons from $\tau (\mu )\to 3\ell ,\ell \gamma \gamma$-decays
• Snowmass 2021 White Paper: Charged lepton flavor violation in the tau sector
• Lepton flavor violation within the Simplest Little Higgs model
• RGE effects on the LFV scale from meson decays
• Charged lepton flavor violation associated with heavy quark production in deep inelastic lepton-nucleon scattering via scalar exchange
• Systematic analysis of search strategies for $L_{\mu }-L_{\tau }$ gauge bosons at Belle II
• Neutron stars can shine a light on elusive lepton-flavor-violating dark matter
• Exploring hadronic de-excitation via Lepton Flavor Violation