# Limits on $\vert \boldsymbol U_{{{\boldsymbol \tau}}\boldsymbol x}\vert ^2$ as a Function of ${\boldsymbol m}_{{{\boldsymbol \nu}_{{x}}}}$ INSPIRE search

VALUE CL% DOCUMENT ID TECN  COMMENT
• • • We do not use the following data for averages, fits, limits, etc. • • •
$<0.01$ 90 1
 2002
CHRM ${\mathit m}_{{{\mathit \nu}_{{x}}}}$=45 MeV
$<1.4 \times 10^{-4}$ 90 1
 2002
CHRM ${\mathit m}_{{{\mathit \nu}_{{x}}}}$=180 MeV
$<0.025$ 90
 2001
${\mathit m}_{{{\mathit \nu}_{{x}}}}$=45 MeV
$<0.002$ 90
 2001
${\mathit m}_{{{\mathit \nu}_{{x}}}}$=140 MeV
$<2 \times 10^{-5}$ 95 2
 1997 I
DLPH ${\mathit m}_{{{\mathit \nu}_{{x}}}}$=6 GeV
$<3 \times 10^{-5}$ 95 2
 1997 I
DLPH ${\mathit m}_{{{\mathit \nu}_{{x}}}}$=50 GeV
$<6.2 \times 10^{-8}$ 95
 1990 S
L3 ${\mathit m}_{{{\mathit \nu}_{{x}}}}$=20 GeV
$<5.1 \times 10^{-10}$ 95
 1990 S
L3 ${\mathit m}_{{{\mathit \nu}_{{x}}}}$=40 GeV
$\text{all values ruled out}$ 95 3
 1990
MRK2 ${\mathit m}_{{{\mathit \nu}_{{x}}}}$ $<$ $19.6$ GeV
$<1 \times 10^{-10}$ 95 3
 1990
MRK2 ${\mathit m}_{{{\mathit \nu}_{{x}}}}$ = $22$ GeV
$<1 \times 10^{-11}$ 95 3
 1990
MRK2 ${\mathit m}_{{{\mathit \nu}_{{x}}}}$ = $41$ GeV
$\text{all values ruled out}$ 95
 1990 F
ALEP ${\mathit m}_{{{\mathit \nu}_{{x}}}}$= $25.0-42.7$ GeV
$<1 \times 10^{-13}$ 95
 1990 F
ALEP ${\mathit m}_{{{\mathit \nu}_{{x}}}}$= $42.7-45.7$ GeV
$<0.05$ 80
 1988
HRS ${\mathit m}_{{{\mathit \nu}_{{x}}}}=2.5$ GeV
$<9 \times 10^{-5}$ 80
 1988
HRS ${\mathit m}_{{{\mathit \nu}_{{x}}}}=4.5$ GeV
1  ORLOFF 2002 use the negative result of a search for neutral particles decaying into two electrons performed by CHARM to get these limits for a mostly isosinglet heavy neutrino.
2  ABREU 1997I long-lived ${{\mathit \nu}_{{x}}}$ analysis. Short-lived analysis extends limit to lower masses with decreasing sensitivity.
3  BURCHAT 1990 includes the analyses reported in JUNG 1990 , ABRAMS 1989C, and WENDT 1987 .
References:
 ORLOFF 2002
PL B550 8 Limits on the Mixing of ${{\mathit \tau}}$ Neutrino to Heavy Neutrinos
 ASTIER 2001
PL B506 27 Search for Heavy Neutrinos Mixing with ${{\mathit \tau}}$ Neutrinos
 ABREU 1997I
ZPHY C74 57 Search for Neutral Heavy Leptons Produced in ${{\mathit Z}}$ Decays
PL B251 321 A Search for Heavy Charged and Neutral Leptons from ${{\mathit Z}^{0}}$ Decays
PR D41 3542 A Search for Decays of the ${{\mathit Z}^{0}}$ to Unstable Neutral Leptons with Mass between 2.5 and 22 GeV
PL B236 511 A Search for New Quarks and Leptons from ${{\mathit Z}^{0}}$ Decay
PR D37 577 Experimental Limits on Massive Neutrinos from ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Annihilation at 29 GeV
PRL 64 1091 Search for Long-Lived Massive Neutrinos in ${{\mathit Z}^{0}}$ Decays
PRL 63 2447 Searches for New Quarks and Leptons Produced in ${{\mathit Z}^{0}}$ Boson Decay
PRL 58 1810 Search for Heavy Neutrino Production in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Annihilation at 29 GeV