(C) Other neutrino mixing results

The LSND collaboration reported in AGUILAR 2001 a signal which is consistent with ${{\overline{\mathit \nu}}_{{\mu}}}$ $\rightarrow$ ${{\overline{\mathit \nu}}_{{e}}}$ oscillations. In a three neutrino framework, this would be a measurement of $\theta _{12}$ and $\Delta \mathit m{}^{2}_{21}$. This does not appear to be consistent with most of the other neutrino data. The following listings include results from ${{\mathit \nu}_{{\mu}}}$ $\rightarrow$ ${{\mathit \nu}_{{e}}}$ , ${{\overline{\mathit \nu}}_{{\mu}}}$ $\rightarrow$ ${{\overline{\mathit \nu}}_{{e}}}$ appearance and ${{\mathit \nu}_{{\mu}}}$, ${{\overline{\mathit \nu}}_{{\mu}}}$, ${{\mathit \nu}_{{e}}}$, and ${{\overline{\mathit \nu}}_{{e}}}$ disappearance experiments, and searches for $\mathit CPT$ violation.

Search for ${{\mathit \nu}_{{\mu}}}$ or ${{\mathit \nu}_{{e}}}$ $\rightarrow$ ${{\mathit \nu}_{{s}}}$

INSPIRE   PDGID:
S067NUS
VALUE CL% DOCUMENT ID TECN  COMMENT
• • We do not use the following data for averages, fits, limits, etc. • •
$<0.05$ 95 1
ALMAZAN
2023
STEREO
$<0.02$ 95 2
AKER
2022A
 SPEC ${}^{}\mathrm {T}$ $\beta $ decay
$<0.0035$ 95 3
ATIF
2022
RENO, NEOS
$0.42$ ${}^{+0.15}_{-0.17}$ 68 4
BARINOV
2022A
 BEST
$<0.05$ 95 5
ANDRIAMIRADO
2021
PROSPECT
$<0.005$ 95 6
SEREBROV
2021
Neutrino-4
$<0.008$ 95 7
SKROBOVA
2020
DANSS
$<0.01$ 90 8
ALEKSEEV
2018
DANSS
$<0.06$ 90 9
ALMAZAN
2018
STEREO
$<0.1$ 95 10
ASHENFELTER
2018
PROSPECT
$<0.4$ 90 11
AARTSEN
2017B
 ICCB IceCube-DeepCore
$<8 \times 10^{-3}$ 95 12
ABDURASHITOV
2017
T $\beta $ decay
$<0.01$ 90 13
KO
2017
NEOS
$<0.02$ 90 14
AARTSEN
2016
ICCB IceCube
$<4.5 \times 10^{-4}$ 95 15
ADAMSON
2016B
 MINOS, DayaBay
$<0.086$ 95 16
ADAMSON
2016C
 MINS
$<0.011$ 95 17
AN
2016B
 DAYA
18
AMBROSIO
2001
MCRO matter effects
19
FUKUDA
2000
SKAM neutral currents + matter effects
1  ALMAZAN 2023 use inverse beta decay data collected by the STEREO experiment, placed 9 to 11 m from the ILL research reactor, to search for ${{\overline{\mathit \nu}}_{{e}}}$ $\rightarrow$ ${{\overline{\mathit \nu}}_{{s}}}$ oscillations. The ILL research reactor uses highly enriched ${}^{235}\mathrm {U}$ fuel. No indication of the oscillation to sterile neutrinos is found, the stated limit on sin$^2(2\theta _{14})$ correspond to $\Delta $m${}^{2}_{41}$ $\sim{}$ 1 eV${}^{2}$ where the exclusion is maximal. Supersedes ALMAZAN 2018 .
2  AKER 2022A uses the first two science runs of the KATRIN tritium $\beta $ decay neutrino mass experiment to search for an admixture of sterile neutrinos. No evidence is found for a spectral anomaly, indicating such admixture. The resulting limit is on sin$^2(2\theta _{14})$ for sterile neutrino masses m$_{4}$ $<$ 40 eV. It is most restrictive at $\Delta $m${}^{2}_{41}$ $\sim{}$ 400 eV${}^{2}$. A 3+1 model is assumed.
3  ATIF 2022 report results from the combined analysis of the RENO (419 m) and NEOS (24 m) experiments data, collected at the Hanbit Nuclear Power Plant. Results, in terms of sin$^2(2\theta _{14})$, constrain for ${{\overline{\mathit \nu}}_{{e}}}$ $\rightarrow$ ${{\overline{\mathit \nu}}_{{s}}}$ oscillations. The authors report both excluded and allowed parameter combinations. The exclusion result reported here is based on the Feldman-Cousins method and for $\Delta $m${}^{2}_{41}$ $\simeq{}$ $0.55$ eV${}^{2}$. Part of the allowed area is excluded by the STEREO and PROSPECT experiments.
4  BARINOV 2022A report an event deficit observed using the segmented Baksan Ga neutrino detector, exposed to a 3.4 MCi ${}^{51}\mathrm {Cr}$ source. Equal suppression factors are observed for the inner and outer segments. The deficit is interpreted as evidence for oscillations to sterile neutrinos. The result is in terms of sin$^2(2\theta _{14})$, for a best fit of $\Delta $m${}^{2}_{41}$ =3.3 ${}^{+\infty{}}_{-2.3}$ eV${}^{2}$. Some, but not all, of the allowed neutrino parameter space conflicts with other experiments.
5  ANDRIAMIRADO 2021 reports a search for ${{\overline{\mathit \nu}}_{{e}}}$ $\rightarrow$ ${{\overline{\mathit \nu}}_{{s}}}$ oscillations at the HFIR research reactor, at baselines from 6.7 to 9.2 m. The reactor has a ${}^{235}\mathrm {U}$ core. 4 tons of ${}^{6}\mathrm {Li}$-doped liquid scintillator are used in a segmented detector. Oscillations into sterile neutrinos are disfavored. The stated limit for sin$^2(2\theta _{14})$ is for $\Delta $m${}^{2}_{41}$ $\sim{}$ 2 eV${}^{2}$ where the sensitivity is maximal.
6  SEREBROV 2021 searches for ${{\overline{\mathit \nu}}_{{e}}}$ $\rightarrow$ ${{\overline{\mathit \nu}}_{{s}}}$ oscillations with a moveable detector with baseline $6 - 12$ m from the SM-3 research reactor with highly enriched ${}^{235}\mathrm {U}$ fuel. Analyzing the $\mathit L/\mathit E$ dependence a ${{\mathit \chi}^{2}}$ minimum is found at $\Delta $m${}^{2}_{41}$ = $7.3$ $\pm0.13$ $\pm1.16$ eV${}^{2}$ and sin$^2(2\theta _{14})$ = $0.36$ $\pm0.12$. The quoted limit of 0.005 for sin$^2(2\theta _{14})$ corresponds to $\Delta $m${}^{2}_{41}$ $\sim{}$ 2 eV${}^{2}$. This is the result from 720 days of reactor ON and 860 days of reactor OFF measurements. The significance of the ${{\mathit \chi}^{2}}$ minimum is 2.9 $\sigma $. Supersedes SEREBROV 2020 , SEREBROV 2019 and SEREBROV 2018A.
7  SKROBOVA 2020 searches for ${{\overline{\mathit \nu}}_{{e}}}−{{\overline{\mathit \nu}}_{{s}}}$ oscillations using the DANSS detector at 10.7, 11.2, and 12.7 m from the 3.1 GW$_{th}$ power reactor. The DANSS detector is highly segmented and moveable; the positions are changed usually 3 times a week. The analysis is based on the ratio of the events at top and bottom position; the middle position is used for checks of consistency. No evidence for sterile neutrinos is found. The quoted limit 0.008, the smallest excluded sin$^2(2\theta _{14})$, corresponds to $\Delta $m${}^{2}_{41}$ $\sim{}$ 1.0 eV${}^{2}$. Supersedes ALEKSEEV 2018 .
8  ALEKSEEV 2018 searches for ${{\overline{\mathit \nu}}_{{e}}}$ $\rightarrow$ ${{\overline{\mathit \nu}}_{{s}}}$ oscillations using the DANSS detector at 10.7, 11.2, and 12.7 m from the 3.1 GW$_{th}$ power reactor. The DANSS detector is highly segmented and moveable; the positions are changed usually 3 times a week. The analysis is based on the ratio of the events at top and bottom position; the middle position is used for checks of consistency. The best fit point is at $\Delta $m${}^{2}_{41}$ = 1.4 eV${}^{2}$ and sin$^2(2\theta _{14})$ = 0.05 with $\Delta \chi {}^{2}$ = 13.1 (statistical errors only) compared to the fit with 3 active neutrinos only. The quoted limit of 0.01 for sin$^2(2\theta _{14})$ corresponds to $\Delta $m${}^{2}_{41}$ $\sim{}$ 1.0 eV${}^{2}$. Superseded by SKROBOVA 2020 .
9  ALMAZAN 2018 searches for the ${{\overline{\mathit \nu}}_{{e}}}$ $\rightarrow$ ${{\overline{\mathit \nu}}_{{s}}}$ oscillations with baseline from 9.4 to 11.1 m from the ILL research reactor with highly enriched ${}^{235}\mathrm {U}$ fuel. The STEREO detector consists of six separated cells with ${}^{}\mathrm {Gd}$ loaded scintillator, with 15 m water equivalent overburden. The detected rate is $396.3$ $\pm4.7$ ${{\overline{\mathit \nu}}_{{e}}}$/day with signal to background ratio of about 0.9. The reported results corresponds to 66 days of reactor-on. The analysis uses the relative rates normalized to the cell number 1. No indication of the oscillation to the sterile neutrinos is found, the stated limit on sin$^2(2\theta _{14})$ correspond to $\Delta $m${}^{2}_{41}$ $\sim{}$ 3.5 eV${}^{2}$ where the exclusion is maximal. Superseded by ALMAZAN 2023 .
10  ASHENFELTER 2018 searches for the ${{\overline{\mathit \nu}}_{{e}}}$ $\rightarrow$ ${{\overline{\mathit \nu}}_{{s}}}$ oscillations at baseline from 6.7 to 9.2 m from the 85 MW research reactor with pure ${}^{235}\mathrm {U}$ core. The segmented 4 ton ${}^{6}\mathrm {Li}$-doped liquid scintillator is operated with about 1 m water equivalent overburden and recorded $25461$ $\pm283$ IBD events. No indication of oscillations into sterile neutrinos was observed. The stated limit for sin$^2(2\theta _{14})$ is for $\Delta $m${}^{2}_{41}$ $\sim{}$ 2 eV${}^{2}$ where the sensitivity is maximal.
11  AARTSEN 2017B uses three years of upward-going atmospheric neutrino data in the energy range of 10-60 GeV to constrain their disappearance into light sterile neutrinos. The reported limit sin$^2\theta _{24}$ $<$ 0.11 at 90$\%$ C.L. is for $\Delta $m${}^{2}_{41}$ = 1.0 eV${}^{2}$. We convert the result to sin$^22\theta _{24}$ for the listing. AARTSEN 2017B also reports cos $^2\theta _{24}\cdot{}$sin$^2\theta _{34}$ $<$ 0.15 at 90$\%$ C.L. for $\Delta $m${}^{2}_{41}$ = 1.0 eV${}^{2}$.
12  ABDURASHITOV 2017 use the Troitsk nu-mass experiment to search for sterile neutrinos with mass 0.1 - 2 keV. We convert the reported limit from $\mathit U{}^{2}_{e4}<$0.002 to sin$^22\theta _{14}<$0.008 assume $\mathit U_{e4}\sim{}$ sin$\theta _{14}$. The stated limit corresponds to the smallest $\mathit U{}^{2}_{e4}$. The exclusion curve begins at $\mathit U{}^{2}_{e4}$ of 0.02 for m$_{4}$ = 0.1 keV.
13  KO 2017 reports on short baseline reactor oscillation search ( ${{\overline{\mathit \nu}}_{{e}}}$ $\rightarrow$ ${{\overline{\mathit \nu}}_{{s}}}$ ), motivated be the so-called "reactor antineutrino anomaly". The experiment is conducted at 23.7 m from the core of unit 5 of the Hanbit Nuclear Power Complex in Korea. the reported limited on sin$^2(2\theta _{41})$ for sterile neutrinos was determined using the reactor antineutrino spectrum determined by the Daya Bay experiment for $\Delta $m${}^{2}_{14}$ around 0.55 eV${}^{2}$ where the sensitivity is maximal. A fraction of the parameter space derived from the "reactor antineutrino anomaly" is excluded by this work. Compared to reactor models an event excess is observed at about 5 MeV, in agreement with other experiments.
14  AARTSEN 2016 use one year of upward-going atmospheric muon neutrino data in the energy range of 320 GeV to 20 TeV to constrain their disappearance into light sterile neutrinos. Sterile neutrinos are expected to produce distinctive zenith distribution for these energies for 0.01 ${}\leq{}\Delta $m${}^{2}{}\leq{}$10 eV${}^{2}$. The stated limit is for sin$^22\theta _{24}$ at $\Delta $m${}^{2}$ around 0.3 eV${}^{2}$.
15  ADAMSON 2016B combine the results of AN 2016B, ADAMSON 2016C, and Bugey-3 reactor experiments to constrain ${{\mathit \nu}_{{\mu}}}$ to ${{\mathit \nu}_{{e}}}$ mixing through oscillations into light sterile neutrinos. The stated limit for sin$^22\theta _{ {{\mathit \mu}} {{\mathit e}} }$ is at $\vert \Delta $m${}^{2}_{41}\vert $ = 1.2 eV${}^{2}$.
16  ADAMSON 2016C use the NuMI beam and exposure of $10.56 \times 10^{20}$ protons on target to search for the oscillation of ${{\mathit \nu}_{{\mu}}}$ dominated beam into light sterile neutrinos with detectors at 1.04 and 735 km. The reported limit sin$^2(\theta _{24})$ $<$ 0.022 at 95$\%$ C.L. is for $\vert \Delta $m${}^{2}_{41}\vert $ = 0.5 eV${}^{2}$. We convert the result to sin$^2(2\theta _{24})$ for the listing.
17  AN 2016B utilize 621 days of data to place limits on the ${{\overline{\mathit \nu}}_{{e}}}$ disappearance into a light sterile neutrino. The stated limit corresponds to the smallest sin$^2(2\theta _{14})$ at $\vert \Delta $m${}^{2}_{41}\vert $ $\sim{}$ $0.03$ eV${}^{2}$ (obtained from Figure 3 in AN 2016B). The exclusion curve begins at $\vert \Delta $m${}^{2}_{41}\vert \sim{}1.5 \times 10^{-4}$ eV${}^{2}$ and extends to $\sim{}0.25$ eV${}^{2}$. The analysis assumes sin$^2(2\theta _{12})$ = $0.846$ $\pm0.021$, $\Delta $m${}^{2}_{21}$ = ($7.53$ $\pm0.18$) $ \times 10^{-5}$ eV${}^{2}$, and $\vert \Delta $m${}^{2}_{32}\vert $ = ($2.44$ $\pm0.06$) $ \times 10^{-3}$ eV${}^{2}$.
18  AMBROSIO 2001 tested the pure 2-flavor ${{\mathit \nu}_{{\mu}}}$ $\rightarrow$ ${{\mathit \nu}_{{s}}}$ hypothesis using matter effects which change the shape of the zenith-angle distribution of upward through-going muons. With maximum mixing and $\Delta $m${}^{2}$around $0.0024~$eV${}^{2}$, the ${{\mathit \nu}_{{\mu}}}$ $\rightarrow$ ${{\mathit \nu}_{{s}}}$ oscillation isdisfavored with 99$\%$ confidence level with respect to the ${{\mathit \nu}_{{\mu}}}$ $\rightarrow$ ${{\mathit \nu}_{{\tau}}}$ hypothesis.
19  FUKUDA 2000 tested the pure 2-flavor ${{\mathit \nu}_{{\mu}}}$ $\rightarrow$ ${{\mathit \nu}_{{s}}}$ hypothesis using three complementary atmospheric-neutrino data samples. With this hypothesis, zenith-angle distributions are expected to show characteristic behavior due to neutral currents and matter effects. In the $\Delta $m${}^{2}$ and sin$^22\theta $region preferred by the Super-Kamiokande data, the ${{\mathit \nu}_{{\mu}}}$ $\rightarrow$ ${{\mathit \nu}_{{s}}}$ hypothesis isrejected at the 99$\%$ confidence level, while the ${{\mathit \nu}_{{\mu}}}$ $\rightarrow$ ${{\mathit \nu}_{{\tau}}}$ hypothesis consistently fits all of the data sample.
References:
ALMAZAN 2023
NAT 613 257 STEREO neutrino spectrum of $^{235}$U fission rejects sterile neutrino hypothesis
AKER 2022A
PR D105 072004 Improved eV-scale sterile-neutrino constraints from the second KATRIN measurement campaign
ATIF 2022
PR D105 L111101 Search for sterile neutrino oscillations using RENO and NEOS data
BARINOV 2022A
PR C105 065502 Search for electron-neutrino transitions to sterile states in the BEST experiment
Also
PRL 128 232501 Results from the Baksan Experiment on Sterile Transitions (BEST)
ANDRIAMIRADO 2021
PR D103 032001 Improved short-baseline neutrino oscillation search and energy spectrum measurement with the PROSPECT experiment at HFIR
SEREBROV 2021
PR D104 032003 Search for sterile neutrinos with the Neutrino-4 experiment and measurement results
SKROBOVA 2020
IJMP A35 2044015
ALEKSEEV 2018
PL B787 56 Search for sterile neutrinos at the DANSS experiment
ALMAZAN 2018
PRL 121 161801 Sterile Neutrino Constraints from the STEREO Experiment with 66 Days of Reactor-On Data
ASHENFELTER 2018
PRL 121 251802 First search for short-baseline neutrino oscillations at HFIR with PROSPECT
AARTSEN 2017B
PR D95 112002 Search for Sterile Neutrino Mixing using Three Years of IceCube DeepCore Data
ABDURASHITOV 2017
JETPL 105 753 First Measeurements in Search for keV-Sterile Neutrino in Tritium beta-Decay by Troitsk nu-Mass Experiment
KO 2017
PRL 118 121802 Sterile Neutrino Search at the NEOS Experiment
AARTSEN 2016
PRL 117 071801 Searches for Sterile Neutrinos with the IceCube Detector
ADAMSON 2016C
PRL 117 151803 Search for Sterile Neutrinos Mixing with Muon Neutrinos in MINOS
ADAMSON 2016B
PRL 117 151801 Limits on Active to Sterile Neutrino Oscillations from Disappearance Searches in the MINOS, Daya Bay, and Bugey-3 Experiments
AN 2016B
PRL 117 151802 Improved Search for a Light Sterile Neutrino with the Full Configuration of the Daya Bay Experiment
AMBROSIO 2001
PL B517 59 Matter Effects in Upward Going Muons and Sterile Neutrino Oscillations
FUKUDA 2000
PRL 85 3999 ${{\mathit \tau}}$ Neutrinos Favored over Sterile Neutrinos in Atmospheric Muon Neutrino Oscillations