Event Excess in the MiniBooNE Search forν¯μ→ν¯eOscillations

Abstract

The MiniBooNE experiment at Fermilab reports results from a search for ¯ν_{μ}→¯ν_{e} oscillations, using a data sample corresponding to 5.66×10²⁰ protons on target. An excess of 20.9±14.0 events is observed in the energy range 475<E_{ν}^{QE}<1250 MeV, which, when constrained by the observed ¯ν_{μ} events, has a probability for consistency with the background-only hypothesis of 0.5%. On the other hand, fitting for ¯ν_{μ}→¯ν_{e} oscillations, the best-fit point has a χ² probability of 8.7%. The data are consistent with ¯ν_{μ}→¯ν_{e} oscillations in the 0.1 to 1.0 eV² Δm² range and with the evidence for antineutrino oscillations from the Liquid Scintillator Neutrino Detector at Los Alamos National Laboratory.

Searching for sterile neutrinos at the ESSνSB

“…However, KARMEN did not observe any signal for similar values of L/E [3]. The dedicated MiniBooNE experiment [4][5][6] has to this day not confirmed or disproved the LSND anomaly. On the other hand, ν e [7][8][9][10] andν e [11][12][13] disappearance experiments seem to observe a deficit which would be compatible with sterile neutrino oscillations in the eV 2 range, while no deficit at all has been observed in any of the ν µ disappearance experiments [14,15].…”

“…Since the flux peak would be located around 250 MeV, a distance to the detector of 1 km would be needed in order to match the maximum of the oscillation, assuming a squared mass splitting ∆m 2 41 ∼ O(1 eV) (as LSND [2] and MiniBooNE [4][5][6] results seem to indicate). Since the main goal of the ESSνSB experiment would be the search for CP violation, we…”

Electron electric dipole moment in Inverse Seesaw models

“…Other than the above motivation, some of the current neutrino oscillation experiments (reactor [24][25][26], accelerator [27][28][29][30] and Gallium [31,32]) suggest the existence of sterile fermions with masses in the eV range. This would imply that instead of the three-neutrino mixing scheme (in oscillation phenomena), one would have a 3 + 1-neutrino (or 3+more) mixing schemes (see, for instance, [33]).…”

Effect of steriles states on lepton magnetic moments and neutrinoless double beta decay

“…Extensions of the Standard Model (SM) by sterile neutrinos have received increasing attention in recent years: in addition to their rôle in numerous well motivated scenarios of neutrino mass generation, the existence of sterile neutrinos is suggested by the reactor [1][2][3], accelerator [4][5][6][7] and Gallium anomalies [8,9], as well as by certain indications from large scale structure formation [10,11].…”