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Limits on Coupling of ${{\mathit \mu}}$ to ${{\mathit \nu}_{{x}}}$ as Function of ${\mathit m}_{{{\mathit \nu}_{{x}}}}$

Searches for Decays of Massive ${{\mathit \nu}}$

Limits on $\vert \mathit U_{{{\mathit \mu}}\mathit x}\vert ^2$ as function of ${\mathit m}_{{{\mathit \nu}_{{x}}}}$

VALUE

CL%

DOCUMENT ID

TECN

COMMENT

• • We do not use the following data for averages, fits, limits, etc. • •

$<5 \times 10^{-7}$

90

CCFR

${\mathit m}_{{{\mathit \nu}_{{x}}}}$=0.28 GeV

$<8 \times 10^{-8}$

90

CCFR

${\mathit m}_{{{\mathit \nu}_{{x}}}}$=0.37 GeV

$<5 \times 10^{-7}$

90

CCFR

${\mathit m}_{{{\mathit \nu}_{{x}}}}$= 0.50 GeV

$<6 \times 10^{-8}$

90

CCFR

${\mathit m}_{{{\mathit \nu}_{{x}}}}$= 1.50 GeV

$<2 \times 10^{-5}$

95

DLPH

${\mathit m}_{{{\mathit \nu}_{{x}}}}$=6 GeV

$<3 \times 10^{-5}$

95

DLPH

${\mathit m}_{{{\mathit \nu}_{{x}}}}$=50 GeV

$<3 \times 10^{-6}$

90

CNTR

${\mathit m}_{{{\mathit \nu}_{{x}}}}$ = 1 GeV

$<3 \times 10^{-5}$

90

CHM2

${\mathit m}_{{{\mathit \nu}_{{x}}}}$ = 2 GeV

$<6.2 \times 10^{-8}$

95

L3

${\mathit m}_{{{\mathit \nu}_{{x}}}}$=20 GeV

$<5.1 \times 10^{-10}$

95

L3

${\mathit m}_{{{\mathit \nu}_{{x}}}}$=40 GeV

$\text{all values ruled out}$

95

MRK2

${\mathit m}_{{{\mathit \nu}_{{x}}}}$ $<$ $19.6$ GeV

$<1 \times 10^{-10}$

95

MRK2

${\mathit m}_{{{\mathit \nu}_{{x}}}}$ = $22$ GeV

$<1 \times 10^{-11}$

95

MRK2

${\mathit m}_{{{\mathit \nu}_{{x}}}}$ = $41$ GeV

$\text{all values ruled out}$

95

ALEP

${\mathit m}_{{{\mathit \nu}_{{x}}}}$= $25.0-42.7$ GeV

$<1 \times 10^{-13}$

95

ALEP

${\mathit m}_{{{\mathit \nu}_{{x}}}}$= $42.7-45.7$ GeV

$<5 \times 10^{-3}$

90

HRS

${\mathit m}_{{{\mathit \nu}_{{x}}}}=1.8$ GeV

$<2 \times 10^{-5}$

90

HRS

${\mathit m}_{{{\mathit \nu}_{{x}}}}$=4 GeV

$<3 \times 10^{-6}$

90

HRS

${\mathit m}_{{{\mathit \nu}_{{x}}}}$=6 GeV

$<1 \times 10^{-7}$

90

CNTR

${\mathit m}_{{{\mathit \nu}_{{x}}}}$=200 MeV

$<3 \times 10^{-9}$

90

CNTR

${\mathit m}_{{{\mathit \nu}_{{x}}}}$=300 MeV

$<4 \times 10^{-4}$

90

CNTR

${\mathit m}_{{{\mathit \nu}_{{x}}}}=1.5$ GeV

$<4 \times 10^{-3}$

90

CNTR

${\mathit m}_{{{\mathit \nu}_{{x}}}}=2.5$ GeV

$<0.009$

90

CNTR

${\mathit m}_{{{\mathit \nu}_{{x}}}}$=5 GeV

$<0.1$

90

CNTR

${\mathit m}_{{{\mathit \nu}_{{x}}}}$=10 GeV

$<8 \times 10^{-4}$

90

CNTR

${\mathit m}_{{{\mathit \nu}_{{x}}}}$=600 MeV

$<1.2 \times 10^{-5}$

90

CNTR

${\mathit m}_{{{\mathit \nu}_{{x}}}}=1.7$ GeV

$<3 \times 10^{-8}$

90

CNTR

${\mathit m}_{{{\mathit \nu}_{{x}}}}$=200 MeV

$<6 \times 10^{-9}$

90

CNTR

${\mathit m}_{{{\mathit \nu}_{{x}}}}$=350 MeV

$<1 \times 10^{-6}$

90

CNTR

${\mathit m}_{{{\mathit \nu}_{{x}}}}$=500 MeV

$<1 \times 10^{-7}$

90

CNTR

${\mathit m}_{{{\mathit \nu}_{{x}}}}$=1600 MeV

$<0.8 \times 10^{-5}$

90

HLBC

${\mathit m}_{{{\mathit \nu}_{{x}}}}=0.4$ GeV

$<1.0 \times 10^{-7}$

90

HLBC

${\mathit m}_{{{\mathit \nu}_{{x}}}}=1.5$ GeV

¹	VAITAITIS 1999 search for ${{\mathit L}_{{\mu}}^{0}}$ $\rightarrow$ ${{\mathit \mu}}{{\mathit X}}$ . See paper for rather complicated limit as function of ${\mathit m}_{{{\mathit \nu}_{{x}}}}$.

²	ABREU 1997I long-lived ${{\mathit \nu}_{{x}}}$ analysis. Short-lived analysis extends limit to lower masses with decreasing sensitivity except at $3.5$ GeV, where the limit is the same as at 6 GeV.

³	VILAIN 1995C is a search for the decays of heavy iso-singlet neutrinos produced by neutral current neutrino interactions. Limits were quoted for masses in the range from 0.3 to 24 GeV. The best limit is listed above.

⁴	BURCHAT 1990 includes the analyses reported in JUNG 1990 , ABRAMS 1989C, and WENDT 1987 .

⁵	See also limits on $\vert {{\mathit U}_{{3x}}}\vert $ from WENDT 1987 .

⁶

COOPER-SARKAR 1985 also give limits based on model-dependent assumptions for ${{\mathit \nu}_{{\tau}}}$ flux. We do not list these. Note that for this bound to be nontrivial, $\mathit x$ is not equal to 3, i.e. ${{\mathit \nu}_{{x}}}$ cannot be the dominant mass eigenstate in ${{\mathit \nu}_{{\tau}}}$ since ${\mathit m}_{{{\mathit \nu}_{{3}}}}$ $<$70 MeV (ALBRECHT 1985I). Also, of course, $\mathit x$ is not equal to 1 or 2, so a fourth generation would be required for this bound to be nontrivial.

References:

PRL 83 4943

Search for Neutral Heavy Leptons in a High Energy Neutrino Beam

ZPHY C74 57

Search for Neutral Heavy Leptons Produced in ${{\mathit Z}}$ Decays

ZPHY C75 580 (errat.)

Erratum: ABREU 1997I Search for Neutral Heavy Leptons Produced in ${{\mathit Z}}$ Decays

PR D52 6

Search for Neutral Weakly Interacting Massive Particles in the Fermilab Tevatron Wide Band Neutrino Beam

PL B351 387

Search for Heavy Isosinglet Neutrinos

PL B343 453

Search for Heavy Isosinglet Neutrinos

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

PL B203 332

Further Limit on Heavy Neutrino Coupling

PRL 59 1397

Search for Neutral Heavy Leptons from ${{\mathit \nu}}$ Nucleus Scattering

ZPHY C31 21

Mass and Lifetime Limits on New Longlived Particles in 300 ${\mathrm {GeV/}}\mathit c$ ${{\mathit \pi}^{-}}$ Interactions

PL 166B 479

Search for Neutrino Decay

PL 166B 473

A Search for Decays of Heavy Neutrinos in the Mass Range of 0.5 $−$ 2.8 GeV

PL 160B 207

Search for Heavy Neutrino Decays in the BEBC Beam Dump Experiment

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