# (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 MiniBooNE experiment, reported in AGUILAR-AREVALO 2007 , does a two-neutrino analysis which, assuming $\mathit CP$ conservation, rules out AGUILAR 2001 . However, the MiniBooNE antineutrino data reported in AGUILAR-AREVALO 2013A are consistent with the signal reported in AGUILAR 2001 . The following listings include results which might be relevant towards understanding these observations. They include searches for ${{\mathit \nu}_{{\mu}}}$ $\rightarrow$ ${{\mathit \nu}_{{e}}}$ , ${{\overline{\mathit \nu}}_{{\mu}}}$ $\rightarrow$ ${{\overline{\mathit \nu}}_{{e}}}$ , sterile neutrino oscillations, and $\mathit CPT$ violation.

# sin$^2(2{}\theta )$ for Large'' $\Delta \boldsymbol m{}^{2}$ ( ${{\boldsymbol \nu}_{{\mu}}}$ $\rightarrow$ ${{\boldsymbol \nu}_{{e}}}$ ) INSPIRE search

VALUE ($10^{-3}$) CL% DOCUMENT ID TECN  COMMENT
• • • We do not use the following data for averages, fits, limits, etc. • • •
$<7.2$ 90
 2013
OPER $\Delta \mathit m{}^{2}>$ 0.1 eV${}^{2}$
$0.8\text{ to }3$ 90 1
 2013 A
MBNE MiniBooNE
$<11$ 90 2
 2013
ICAR ${{\mathit \nu}_{{\mu}}}$ $\rightarrow$ ${{\mathit \nu}_{{e}}}$
$<6.8$ 90 3
 2013 A
ICAR ${{\mathit \nu}_{{\mu}}}$ $\rightarrow$ ${{\mathit \nu}_{{e}}}$
$<100$ 90 4
 2012
MBNE MiniBooNE/SciBooNE
$<1.8$ 90 5
 2007
MBNE MiniBooNE
$<110$ 90 6
 2004
K2K Water Cherenkov
$<1.4$ 90
 2003
NOMD CERN SPS
$<1.6$ 90
 2002
NTEV NUTEV FNAL
7
 2001
LSND ${{\mathit \nu}_{{\mu}}}$ $\rightarrow$ ${{\mathit \nu}_{{e}}}$ osc.prob.
$0.5\text{ to }30$ 95 8
 1998
LSND ${{\mathit \nu}_{{\mu}}}$ $\rightarrow$ ${{\mathit \nu}_{{e}}}$
$<3.0$ 90 9
 1996
CHARM/CDHS
$<9.4$ 90
 1994 C
CHM2 CERN SPS
$<5.6$ 90 10
 1994 C
CHM2 CERN SPS
1  Based on ${{\mathit \nu}_{{\mu}}}$ $\rightarrow$ ${{\mathit \nu}_{{e}}}$ appearance of $162.0$ $\pm47.8$ events; marginally compatible with two neutrino oscillations. The best fit value is sin$^22\theta$ = 0.002.
2  ANTONELLO 2013 use the ICARUS T600 detector at LNGS and $\sim{}$20 GeV beam of ${{\mathit \nu}_{{\mu}}}$ from CERN 730 km away to search for an excess of ${{\mathit \nu}_{{e}}}$ events. Two events are found with $3.7$ $\pm0.6$ expected from conventional sources. This result excludes some parts of the parameter space expected by LSND. Superseded by ANTONELLO 2013A.
3  Based on four events with a background of $6.4$ $\pm0.9$ from conventional sources with an average energy of 20 GeV and 730 km from the source of ${{\mathit \nu}_{{\mu}}}$.
4  MAHN 2012 is a combined fit of MiniBooNE and SciBooNE neutrino data.
5  The limit is sin$^22\theta$ $<$ $0.9 \times 10^{-3}$ at $\Delta$ = 2 eV${}^{2}$. That value of $\Delta$ corresponds to the smallest mixing angle consistent with the reported signal from LSND in AGUILAR 2001 .
6  The limit becomes sin$^22\theta$ $<$ 0.15 at $\Delta$ = $2.8 \times 10^{-3}$ eV${}^{2}$, the bets-fit value of the ${{\mathit \nu}_{{\mu}}}$ disappearance analysis in K2K.
7  AGUILAR 2001 is the final analysis of the LSND full data set of the search for the ${{\mathit \nu}_{{\mu}}}$ $\rightarrow$ ${{\mathit \nu}_{{e}}}$ oscillations. See footnote in preceding table for further details.
8  ATHANASSOPOULOS 1998 report ($0.26$ $\pm0.10$ $\pm0.05)\%$ for the oscillation probability; the value of sin$^22\theta$ for large $\Delta \mathit m{}^{2}$ is deduced from this probability. See footnote in preceding table for further details, and see the paper for a plot showing allowed regions. If effect is due to oscillation, it is most likely to be intermediate sin$^22\theta$ and $\Delta \mathit m{}^{2}$. See also ATHANASSOPOULOS 1998B.
9  LOVERRE 1996 uses the charged-current to neutral-current ratio from the combined CHARM (ALLABY 1986 ) and CDHS (ABRAMOWICZ 1986 ) data from 1986.
10  VILAIN 1994C limit derived by combining the ${{\mathit \nu}_{{\mu}}}$ and ${{\overline{\mathit \nu}}_{{\mu}}}$ data assuming $\mathit CP$ conservation.
References:
 AGAFONOVA 2013
JHEP 1307 004 Search for ${{\mathit \nu}_{{\mu}}}\rightarrow{{\mathit \nu}_{{e}}}$ Oscillations with the OPERA Experiment in the CNGS Beam
 AGUILAR-AREVALO 2013A
PRL 110 161801 Improved Search for ${{\overline{\mathit \nu}}_{{\mu}}}\leftrightarrow{{\overline{\mathit \nu}}_{{e}}}$ Oscillations in the MiniBooNE Experiment
 ANTONELLO 2013A
EPJ C73 2599 Search for Anomalies in the ${{\mathit \nu}_{{e}}}$ Appearance from a ${{\mathit \nu}_{{\mu}}}$ Beam
 ANTONELLO 2013
EPJ C73 2345 Experimental Search for the "LSND Anomaly" with the ICARUS Detector in the CNGS Neutrino Beam
 MAHN 2012
PR D85 032007 Dual Baseline Search for Muon Neutrino Disappearance at 0.5 eV${}^{2}$ < $\Delta$m${}^{2}$ < 40 eV${}^{2}$
 AGUILAR-AREVALO 2007
PRL 98 231801 Search for Electron Neutrino Appearance at the $\Delta \mathit m{}^{2}\sim{}$1 eV${}^{2}$ Scale
 AHN 2004
PRL 93 051801 Search for Electron Neutrino Appearance in 250 km Long-baseline Experiment
 ASTIER 2003
PL B570 19 Search for ${{\mathit \nu}_{{\mu}}}$ $\rightarrow$ ${{\mathit \nu}_{{e}}}$ Oscillations in the NOMAD Experiment
 AVVAKUMOV 2002
PRL 89 011804 A Search for ${{\mathit \nu}_{{\mu}}}-{{\mathit \nu}_{{e}}}$ and ${{\overline{\mathit \nu}}_{{\mu}}}-{{\overline{\mathit \nu}}_{{e}}}$ Oscillations at NUTeV
 AGUILAR 2001
PR D64 112007 Evidence for Neutrino Oscillations from the Observation of ${{\overline{\mathit \nu}}_{{e}}}$ Appearance in a ${{\overline{\mathit \nu}}_{{\mu}}}$ Beam
 ATHANASSOPOULOS 1998
PRL 81 1774 Evidence for ${{\mathit \nu}_{{\mu}}}$ $\leftrightarrow$ ${{\mathit \nu}_{{e}}}$ Oscillations from the LSND
 LOVERRE 1996
PL B370 156 Limits on ${{\mathit \nu}_{{\mu}}}$ Oscillations from the Measurement of the Ratio of 0${{\mathit \mu}^{\pm}}$ to 1${{\mathit \mu}^{\pm}}$ Events at the CERN Narrow Band Neutrino Beam
 VILAIN 1994C
ZPHY C64 539 Search for Muon to Electron Neutrino Oscillations
 ATHANASSOPOULOS 1998B
PR C58 2489 Evidence for ${{\mathit \nu}_{{\mu}}}$ $\leftrightarrow$ ${{\mathit \nu}_{{e}}}$ Oscillations from Pion Decay in Flight Neutrinos
 ALLABY 1986
PL B177 446 A Precise Determination of the Electroweak Mixing Angle from Semileptonic Neutrino Scattering
 ABRAMOWICZ 1986
PRL 57 298 A Precision Measurement of sin$^2\theta _{W}$ from Semileptonic Neutrino Scattering