$\bf{
<0.19}$
|
OUR EVALUATION
|
$<0.17$ |
90 |
1 |
|
SPEC |
• • • We do not use the following data for averages, fits, limits, etc. • • • |
$<0.15$ |
|
2 |
|
COSM |
$<0.48$ |
|
3 |
|
COSM |
$<0.3$ |
|
4 |
|
COSM |
$<0.42$ |
|
4 |
|
COSM |
$<0.50$ |
90 |
5 |
|
SPEC |
$<0.65$ |
90 |
|
|
ASPK |
1
ASSAMAGAN 1996 measurement of ${{\mathit p}_{{\mu}}}$ from ${{\mathit \pi}^{+}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \nu}}$ at rest combined with JECKELMANN 1994 Solution$~$B pion mass yields ${{\mathit m}^{2}}_{{{\mathit \nu}}}$ = $-0.016$ $\pm0.023$ with corresponding Bayesian limit listed above. If Solution$~$A is used, ${{\mathit m}^{2}}_{{{\mathit \nu}}}$ = $-0.143$ $\pm0.024$ MeV${}^{2}$. Replaces ASSAMAGAN 1994 .
|
2
DOLGOV 1995 removes earlier assumptions (DOLGOV 1993 ) about thermal equilibrium below $\mathit T_{{\mathrm {QCD}}}$ for wrong-helicity Dirac neutrinos (ENQVIST 1993 , FULLER 1991 ) to set more stringent limits.
|
3
ENQVIST 1993 bases limit on the fact that thermalized wrong-helicity Dirac neutrinos would speed up expansion of early universe, thus reducing the primordial abundance. FULLER 1991 exploits the same mechanism but in the older calculation obtains a larger production rate for these states, and hence a lower limit. Neutrino lifetime assumed to exceed nucleosynthesis time, $\sim{}1~$s.
|
4
Assumes neutrino lifetime $>1~$s. For Dirac neutrinos only. See also ENQVIST 1993 .
|
5
ANDERHUB 1982 kinematics is insensitive to the pion mass.
|