40 research outputs found
Sensitivity of the intensity frontier experiments for neutrino and scalar portals: analytic estimates
In recent years, a number of intensity-frontier experiments have been
proposed to search for feebly interacting particles with a mass in the GeV
range. We show analytically how the characteristic shape of the sensitivity
regions of such experiments - upper and lower boundaries of the probed region,
the maximal mass reach - depends on the parameters of the experiments, taking
the SHiP and the MATHUSLA experiments as an example. We find a good agreement
of our estimates with the results of the Monte Carlo simulations.Comment: Journal versio
Probing new physics with displaced vertices: muon tracker at CMS
Long-lived particles can manifest themselves at the LHC via "displaced
vertices" - several charged tracks originating from a position separated from
the proton interaction point by a macroscopic distance. Here we demonstrate a
potential of the muon trackers at the CMS experiment for displaced vertex
searches. We use heavy neutral leptons and Chern-Simons portal as two examples
of long-lived particles for which the CMS muon tracker can provide essential
information about their properties.Comment: Journal versio
Search for the dipole portal of heavy neutral leptons at future colliders
In this paper, we study the potential of future colliders to explore the
parameter space of heavy neutral leptons (HNLs) through the dipole portal. We
consider hadron colliders such as the LHC in the high luminosity phase and
FCC-hh, and lepton colliders, such as FCC-ee. We consider various signatures
for the HNLs, including the missing energy signature and displaced decays, and
discuss the complementarity between the hadron and lepton colliders. In
particular, we find that thanks to a much clearer environment, FCC-ee may
search for the HNLs with masses up to and proper
lifetimes , which is well beyond the reach of the
experiments to be launched in the next decade.Comment: 13 pages, 10 figure
Complementarity of and for searches of GeV-scale Higgs-like scalars
The rare decays and provide the strongest constraints on the mixing of a light scalar with the Higgs boson for GeV-scale masses. The constraints sensitively depend on the branching ratio to muons. Additional decay channels like an invisible partial width may substantially weaken the constraints. This scenario will be probed at Belle II in inv. We illustrate the complementarity of scalar decays to muons and invisible decays using the currently available results of LHCb and BaBar. We provide two simple model realisations providing a sizeable invisible scalar width, one based on a real scalar and one based on a gauge symmetry. In both examples the scalar decays into heavy neutral leptons which can be motivated by the seesaw mechanism for neutrino masses
Sensitivity of the FACET experiment to Heavy Neutral Leptons and Dark Scalars
We analyze the potential of the recently proposed experiment FACET (Forward-Aperture CMS ExTension) to search for new physics. As an example, we consider the models of Higgs-like scalars with cubic and quartic interactions and Heavy Neutral Leptons. We compare the sensitivity of FACET with that of other proposed “intensity frontier” experiments, including FASER2, SHiP, etc. and demonstrate that FACET could probe an interesting parameter space between the current constraints and the potential reach of the above mentioned proposals
Dipole portal and neutrinophilic scalars at DUNE revisited: the importance of the high-energy neutrino tail
We estimate the sensitivity of the DUNE experiment to new physics particles
interacting with neutrinos, considering the dipole portal to heavy neutral
leptons and a neutrinophilic scalar with lepton-number as examples. We
demonstrate that neutrinos from the high-energy tail of the DUNE flux, with
energies , may significantly improve the
sensitivity to these models, allowing to search for particles as heavy as
. We also study the impact of the so-called tau-optimized
neutrino beam configuration, which slightly improves sensitivity to the new
physics models considered here. For both models, we consider new production
channels (such as deep-inelastic scattering) and provide a detailed comparison
of different signatures in the detector.Comment: 22 pages, 13 figures, consistent with published versio
Phenomenology of GeV-scale scalar portal
We review and revise the phenomenology of the scalar portal -- a new scalar
particle with the mass in GeV range that mixes with the Higgs boson. In
particular, we consider production channels and and show that their contribution is significant. We extend the
previous analysis by comparing the production of scalars from decays of mesons,
of the Higgs bosons and direct production via proton bremsstrahlung, deep
inelastic scattering and coherent scattering on nuclei. Relative efficiency of
the production channels depends on the energy of the beam and we consider the
energies of DUNE, SHiP and LHC-based experiments. We present our results in the
form directly suitable for calculations of experimental sensitivities.Comment: Journal versio
Complementarity of and for searches of GeV-scale Higgs-like scalars
The rare decays and provide the strongest constraints on the mixing of a light scalar with the Higgs boson for GeV-scale masses. The constraints sensitively depend on the branching ratio to muons. Additional decay channels like an invisible partial width may substantially weaken the constraints. This scenario will be probed at Belle II in inv. We illustrate the complementarity of scalar decays to muons and invisible decays using the currently available results of LHCb and BaBar. We provide two simple model realisations providing a sizeable invisible scalar width, one based on a real scalar and one based on a gauge symmetry. In both examples the scalar decays into heavy neutral leptons which can be motivated by the seesaw mechanism for neutrino masses
Complementarity of and for searches of GeV-scale Higgs-like scalars
The rare decays and
provide the strongest constraints on the mixing of a light scalar with the
Higgs boson for GeV-scale masses. The constraints sensitively depend on the
branching ratio to muons. Additional decay channels like an invisible partial
width may substantially weaken the constraints. This scenario will be probed at
Belle II in . We illustrate the complementarity of
scalar decays to muons and invisible decays using the currently available
results of LHCb and BaBar. We provide two simple model realisations providing a
sizeable invisible scalar width, one based on a real scalar and one based on a
gauge symmetry. In both examples the scalar decays into heavy
neutral leptons which can be motivated by the seesaw mechanism for neutrino
masses.Comment: 18 pages, 6 figures, corrected factor 2 in Eq (28) and Figs 3-5, main
conclusions unchanged, matches version accepted by EPJ
Exploring the potential of FCC-hh to search for particles from mesons
The Future Circular Collider (FCC-hh) is a proposed successor of the Large
Hadron Collider (LHC). FCC-hh would push both the energy and intensity
frontiers of searches for new physics particles. In particular, due to higher
energy and luminosity than at the LHC, at FCC-hh there would be produced around
times larger amount of mesons and times of
bosons, which then may decay into feebly interacting particles. In this paper
we demonstrate the potential of FCC-hh by studying its sensitivity to heavy
neutral leptons (HNLs) with masses . We consider various locations
of a displaced decay volume embedded in the planned infrastructure of FCC-hh.
We demonstrate that FCC-hh may substantially improve the reach of the parameter
space of HNLs as compared to the searches proposed at the LHC