Sterile neutrinos ruled out by MicroBooNE experiment

The first results from the Micro-BooNE neutrino detector at Fermilab in the US suggest that the mysterious signals seen in two other neutrino detectors are not the result of hypothetical particles called sterile neutrinos.

Measuring muon tracks in Baikal-GVD using a fast reconstruction algorithm

The Baikal Gigaton Volume Detector (Baikal-GVD) is a km$$^3$$ 3 -scale neutrino detector currently under construction in Lake Baikal, Russia. The detector consists of several thousand optical sensors arranged on vertical strings, with 36 sensors per string. The strings are grouped into clusters of 8 strings each. Each cluster can operate as a stand-alone neutrino detector. The detector layout is optimized for the measurement of astrophysical neutrinos with energies of $$\sim $$ ∼ 100 TeV and above. Events resulting from charged current interactions of muon (anti-)neutrinos will have a track-like topology in Baikal-GVD. A fast $$\chi ^2$$ χ 2 -based reconstruction algorithm has been developed to reconstruct such track-like events. The algorithm has been applied to data collected in 2019 from the first five operational clusters of Baikal-GVD, resulting in observations of both downgoing atmospheric muons and upgoing atmospheric neutrinos. This serves as an important milestone towards experimental validation of the Baikal-GVD design. The analysis is limited to single-cluster data, favoring nearly-vertical tracks.

Can strangelets be detected in a large LAr neutrino detector?

Predicted as possible bound states of up, down and strange quarks, strangelets could be more energetically favourable and more stable than nuclear matter. In this paper we explore the possibility of detecting such particles with the future large liquid argon detectors developed for neutrino physics. Using signals from ionization and scintillation, as well as measuring the range, we suggest that a calorimetric TPC detector is able to put in evidence and to discriminate between light strangelets and normal isotopes at intermediate energies.

GUT-Monopole Searches by Means of Deep Underwater Baikal Neutrino Telescope

The procedure for Grand Unified Theory (GUT) monopole searches by means of the NT200 Baikal neutrino detector is described. Event-selection and background-suppression algorithms are discussed in detail. Limits on the flux of slow monopoles are presented and are compared with theoretical predictions and with the results of other experiments.

Dark photon search at Yemilab, Korea

Dark photons are well motivated hypothetical dark sector particles that could account for observations that cannot be explained by the standard model of particle physics. A search for dark photons that are produced by an electron beam striking a thick tungsten target and subsequently interact in a 3 kiloton-scale neutrino detector in Yemilab, a new underground lab in Korea, is proposed. Dark photons can be produced by “darkstrahlung” or by oscillations from ordinary photons produced in the target and detected by their visible decays, “absorption” or by their oscillation to ordinary photons. By detecting the absorption process or the oscillation-produced photons, a world’s best sensitivity for measurements of the dark-photon kinetic mixing parameter of ϵ2> 1.5 × 10−13(6.1 × 10−13) at the 95% confidence level (C.L.) could be obtained for dark photon masses between 80 eV and 1 MeV in a year-long exposure to a 100 MeV–100 kW electron beam with zero (103) background events. In parallel, the detection of e+e− pairs from decays of dark photons with mass between 1 MeV and ∼86 MeV would have sensitivities of ϵ2>$$ \mathcal{O}\left({10}^{-17}\right)\left(\mathcal{O}\left({10}^{-16}\right)\right) $$ O 10 − 17 O 10 − 16 at the 95% C.L. with zero (103) background events. This is comparable to that of the Super-K experiment under the same zero background assumption.

Sensitivity of the SHiP experiment to light dark matter

Dark matter is a well-established theoretical addition to the Standard Model supported by many observations in modern astrophysics and cosmology. In this context, the existence of weakly interacting massive particles represents an appealing solution to the observed thermal relic in the Universe. Indeed, a large experimental campaign is ongoing for the detection of such particles in the sub-GeV mass range. Adopting the benchmark scenario for light dark matter particles produced in the decay of a dark photon, with αD = 0.1 and mA′ = 3mχ, we study the potential of the SHiP experiment to detect such elusive particles through its Scattering and Neutrino detector (SND). In its 5-years run, corresponding to 2 · 1020 protons on target from the CERN SPS, we find that SHiP will improve the current limits in the mass range for the dark matter from about 1 MeV to 300 MeV. In particular, we show that SHiP will probe the thermal target for Majorana candidates in most of this mass window and even reach the Pseudo-Dirac thermal relic.