Neutral Exotica at FASER$\nu$ and SND@LHC

Abstract

The $(g-2{)}_{\mu }$ anomaly indicates that the second generation of leptons should have new interactions beyond the standard model. The high flux of ${\nu }_{\mu }$ and ${\bar{\nu }}_{\mu }$ at the forward experiments such as FASER$\nu$ and SND@LHC makes them suitable setups to search for new interactions of the second generation leptons. In this paper, we build a model in which the second generation left-handed leptons couple to a new right-handed neutrino, $N$ and a new Higgs doublet which also couples to the quarks. The scattering of high energy ${\nu }_{\mu }$ off nuclei can produce $N$. We investigate how forward experiments can test this model by looking for the $N$ production vertex followed by the displaced vertex of the $N$ decay. Discovering even a single such event can be a harbinger to look for the spectacular signals of the new Higgs doublet production at the LHC. We discuss the possibility of explaining the $(g-2{)}_{\mu }$ anomaly by adding more generations of $N$ which will lead to chain decays of $N$ and multiple leptons with distinct signals both at forward experiments and at the CMS and ATLAS detectors. Finally, we show that by adding a new light singlet scalar mixed with the neutral component of the new Higgs doublet ({\it i.e.,} 2HDM+$S$ model), the statistics of the data sample can be dramatically increased.

19 pages, 6 figures, Accepted for publication in JHEP

References in corpus (19)

• LHAPDF6: parton density access in the LHC precision era
• Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm
• Detecting and Studying High-Energy Collider Neutrinos with FASER at the LHC
• Forward Neutrino Fluxes at the LHC
• Unveiling Hidden Physics at the LHC
• Neutral Current Neutrino Interactions at FASER$\nu$
• EFT at FASER$\nu$
• Neutrino Up-scattering via the Dipole Portal at Forward LHC Detectors
• Probing Light Gauge Bosons in Tau Neutrino Experiments
• Neutrino beam-dump experiment with FASER at the LHC
• Connecting the Muon Anomalous Magnetic Moment and the Multi-lepton Anomalies at the LHC
• First Measurement of Inclusive Electron-Neutrino and Antineutrino Charged Current Differential Cross Sections in Charged Lepton Energy on Argon in MicroBooNE
• The anomalous production of multi-lepton and its impact on the measurement of $Wh$ production at the LHC
• Discovery potential of FASER$\nu$ with contained vertex and through-going events
• Exploring Neutrino-Nucleus Interactions in the GeV Regime using MINERvA
• SLIM at LHC: LHC search power for a model linking dark matter and neutrino mass
• Unravelling the richness of dark sector by FASER$\nu$
• Comment on "Accumulating Evidence for the Associate Production of a Neutral Scalar with Mass around 151 GeV"
• Understanding two same-sign and three leptons with $b$-jets in four top quark events at the LHC

Cited by in corpus (5)

• Investigating the fluxes and physics potential of LHC neutrino experiments
• Probing for chiral $Z^{\prime }$ gauge boson through scattering measurement experiments
• Leptoquark search at the Forward Physics Facility
• Sensitivities on dark photon from the Forward Physics Experiments
• The Forward Physics Facility at the High-Luminosity LHC