${{\mathit b}}$ -baryon ADMIXTURE MEAN LIFE

Each measurement of the ${{\mathit b}}$ -baryon mean life is an average over an admixture of various ${{\mathit b}}$ $~$baryons which decay weakly. Different techniques emphasize different admixtures of produced particles, which could result in a different ${{\mathit b}}$ -baryon mean life. More ${{\mathit b}}$ -baryon flavor specific channels are not included in the measurement.
VALUE ($10^{-12}$ s) EVTS DOCUMENT ID TECN  COMMENT
• • We do not use the following data for averages, fits, limits, etc. • •
$1.218$ ${}^{+0.130}_{-0.115}$ $\pm0.042$ 1
 2007 S
D0 Repl. by ABAZOV 2012U
$1.22$ ${}^{+0.22}_{-0.18}$ $\pm0.04$ 1
 2005 C
D0 Repl. by ABAZOV 2007S
$1.16$ $\pm0.20$ $\pm0.08$ 2
 1999 W
DLPH ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit Z}}$
$1.19$ $\pm0.14$ $\pm0.07$ 3
 1999 W
DLPH ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit Z}}$
$1.14$ $\pm0.08$ $\pm0.04$ 4
 1999 W
DLPH ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit Z}}$
$1.11$ ${}^{+0.19}_{-0.18}$ $\pm0.05$ 5
 1999 W
DLPH ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit Z}}$
$1.29$ ${}^{+0.24}_{-0.22}$ $\pm0.06$ 5
 1998 G
OPAL ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit Z}}$
$1.20$ $\pm0.08$ $\pm0.06$ 6
 1998 D
ALEP ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit Z}}$
$1.21$ $\pm0.11$ 5
 1998 D
ALEP ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit Z}}$
$1.32$ $\pm0.15$ $\pm0.07$ 7
 1996 M
CDF ${{\mathit p}}{{\overline{\mathit p}}}$ at 1.8 TeV
$1.46$ ${}^{+0.22}_{-0.21}$ ${}^{+0.07}_{-0.09}$
 1996 D
DLPH Repl. by ABREU 1999W
$1.10$ ${}^{+0.19}_{-0.17}$ $\pm0.09$ 5
 1996 D
DLPH ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit Z}}$
$1.16$ $\pm0.11$ $\pm0.06$ 5
 1996
OPAL ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit Z}}$
$1.27$ ${}^{+0.35}_{-0.29}$ $\pm0.09$
 1995 S
DLPH Repl. by ABREU 1999W
$1.05$ ${}^{+0.12}_{-0.11}$ $\pm0.09$ 290
 1995 L
ALEP Repl. by BARATE 1998D
$1.04$ ${}^{+0.48}_{-0.38}$ $\pm0.10$ 11 8
 1993 F
DLPH Excess ${{\mathit \Lambda}}{{\mathit \mu}^{-}}$ , decay lengths
$1.05$ ${}^{+0.23}_{-0.20}$ $\pm0.08$ 157 9
 1993
OPAL Excess ${{\mathit \Lambda}}{{\mathit \ell}^{-}}$ , decay lengths
$1.12$ ${}^{+0.32}_{-0.29}$ $\pm0.16$ 101 10
 1992 I
ALEP Excess ${{\mathit \Lambda}}{{\mathit \ell}^{-}}$ , impact parameters
 1 Measured mean life using fully reconstructed ${{\mathit \Lambda}_{{b}}^{0}}$ $\rightarrow$ ${{\mathit J / \psi}}{{\mathit \Lambda}}$ decays.
 2 Measured using ${{\mathit \Lambda}}{{\mathit \ell}^{-}}$ decay length.
 3 Measured using ${{\mathit p}}{{\mathit \ell}^{-}}$ decay length.
 4 This ABREU 1999W result is the combined result of the ${{\mathit \Lambda}}{{\mathit \ell}^{-}}$ , ${{\mathit p}}{{\mathit \ell}^{-}}$ , and excess ${{\mathit \Lambda}}{{\mathit \mu}^{-}}$ impact parameter measurements.
 5 Measured using ${{\mathit \Lambda}_{{c}}}{{\mathit \ell}^{-}}$ and ${{\mathit \Lambda}}{{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ .
 6 Measured using the excess of ${{\mathit \Lambda}}{{\mathit \ell}^{-}}$ , lepton impact parameter.
 7 Measured using ${{\mathit \Lambda}_{{c}}}{{\mathit \ell}^{-}}$ .
 8 ABREU 1993F superseded by ABREU 1996D.
 9 AKERS 1993 superseded by AKERS 1996 .
 10 BUSKULIC 1992I superseded by BUSKULIC 1995L.
References:
 ABAZOV 2007S
PRL 99 142001 Measurement of the ${{\mathit \Lambda}_{{b}}}$ Lifetime in the Exclusive Decay ${{\mathit \Lambda}_{{b}}}$ $\rightarrow$ ${{\mathit J / \psi}}{{\mathit \Lambda}}$
 ABAZOV 2005C
PRL 94 102001 Measurement of the ${{\mathit \Lambda}_{{b}}^{0}}$ Lifetime in the Decay $\rightarrow$ ${{\mathit J / \psi}}{{\mathit \Lambda}^{0}}$ with the ${D0}$ Detector
 ABREU 1999W
EPJ C10 185 Measurement of the Lifetime of ${\mathit {\mathit b}}$ Baryons
 ACKERSTAFF 1998G
PL B426 161 Measurements of the ${{\mathit B}_{{s}}}$ and ${{\mathit \Lambda}_{{b}}}$ Lifetimes
 BARATE 1998D
EPJ C2 197 Measurement of the ${\mathit {\mathit b}}$ Baryon Lifetime and Branching Fractions in ${{\mathit Z}}$ Decays
 ABE 1996M
PRL 77 1439 Measurement of ${{\mathit \Lambda}_{{b}}^{0}}$ Lifetime using ${{\mathit \Lambda}_{{b}}^{0}}$ $\rightarrow$ ${{\mathit \Lambda}_{{c}}^{+}}{{\mathit \ell}^{-}}{{\overline{\mathit \nu}}}$
 ABREU 1996D
ZPHY C71 199 Determination of the Average Lifetime of ${{\mathit b}}$ -Baryons
 AKERS 1996
ZPHY C69 195 Measurement of the Average ${\mathit {\mathit b}}$-Baryon Lifetime and the Product Branching Ratio f(${\mathit {\mathit b}}$ $\rightarrow$ ${{\mathit \Lambda}_{{b}}}$ )$\cdot{}$B( ${{\mathit \Lambda}_{{b}}}$ $\rightarrow$ ${{\mathit \Lambda}}{{\mathit \ell}^{-}}{{\mathit \nu}}{{\mathit X}}$ )
 ABREU 1995S
ZPHY C68 375 Lifetime and Production Rate of Beauty Baryons from ${{\mathit Z}}$ Decays
 BUSKULIC 1995L
PL B357 685 Measurements of the ${{\mathit b}}$ Baryon Lifetime
 ABREU 1993F
PL B311 379 Measurement of ${{\mathit \Lambda}_{{b}}}$ Production and Lifetime in ${{\mathit Z}^{0}}$ Hadronic Decays
 AKERS 1993
PL B316 435 A Measurement of the Average Lifetime of ${{\mathit b}}$ -Flavored Baryons
 Also
PL B281 394 Evidence for ${\mathit {\mathit b}}$-Flavored Baryon Production in ${{\mathit Z}^{0}}$ Decays at LEP
 BUSKULIC 1992I
PL B297 449 A Measurement of the ${\mathit {\mathit b}}$ Baryon Lifetime
 Also
PL B278 209 Evidence for ${\mathit {\mathit b}}$ Baryons in ${{\mathit Z}}$ Decays