Neutrino beam-dump experiment with FASER at the LHC

Abstract

The neutrino physics program at the LHC, which will soon be initiated by the FASER experiment, will provide unique opportunities for precision studies of neutrino interaction vertices at high energies. This will also open up the possibility to search for beyond the standard model (BSM) particles produced in such interactions in the specific high-energy neutrino beam-dump experiment. In this study, we illustrate the prospects for such searches in models with the dipole or Z′ portal to GeV-scale heavy neutral leptons. To this end, we employ both the standard signature of new physics that consists of a pair of oppositely-charged tracks appearing in the decay vessel, and the additional types of searches. These include high-energy photons and single scattered electrons. We show that such a variety of experimental signatures could significantly extend the sensitivity reach of the future multi-purpose FASER 2 detector during the High-Luminosity phase of the LHC.

Constraining active-sterile neutrino transition magnetic moments at DUNE near and far detectors

“…Other studies include considerations of solar neutrinos [4][5][6], atmospheric neutrinos in IceCube [7], or short-baseline experiments [8][9][10][11][12][13]. The HNL dipole portal can be explored also at dedicated experiment for long-lived particle searches such as SHiP [14], FASER [15,16], or MATHUSLA [17,18].…”

The Forward Physics Facility: Sites, Experiments, and Physics Potential

“…[86,87], and dipole interactions have been considered in Ref. [88]. In addition, other portals between fermionic BSM states and the SM have also been investigated, including in supersymmetric models with light neutralinos [84,89], which are a promising solution to the hierarchy problem, and in effective field [4,31,50,91] and references therein.…”

“…A scenario that has been well studied in the literature consists of a Z and a HNL [95][96][97], which could also explain the MiniBooNE anomaly [98]. In addition to its usual neutrino-mixing based production modes, the HNL could be produced through Z → N N decays [99], or via the upscattering of SM neutrinos, νp → N p [88]. If the HNL is produced in neutrino scattering in the upstream rock, it could also be detected via a multiple coincident muon signature traversing the FPF experiments [100].…”

“…FLArE-10 can put an upper limit on the ν τ magnetic moment of a few 10 −8 µ B [209], which is an order of magnitude lower than the current direct bounds from DONUT [210]. In theories with a right-handed neutrino, one can include the so-called dipole portal [139,211,212], L ⊃ 1 2 µ α ν να L σ µν N R F µν , which can lead to excess events at low electron recoil energies [88]. Bounds derived for ν τ are shown in Fig.…”

EFT at FASERν

“…Searches for other types of physics beyond the Standard Model in FASER have previously been discussed in refs. [36][37][38][39][40][41][42][43][44][45][46][47][48][49], while refs. [50][51][52][53] have focused specifically on FASERν.…”