${{\mathit Z}}$ WIDTH

INSPIRE   PDGID:
S044W
OUR EVALUATION is obtained using the fit procedure and correlations as determined by the LEP Electroweak Working Group (see the note “The ${{\mathit Z}}$ boson” and ref. LEP-SLC 2006 ). Corrections as discussed in VOUTSINAS 2020 and JANOT 2020 are also included.
VALUE (GeV) EVTS DOCUMENT ID TECN  COMMENT
$\bf{ 2.4955 \pm0.0023}$ OUR EVALUATION
$2.4955$ $\pm0.0023$ 1
JANOT
2020
• • We do not use the following data for averages, fits, limits, etc. • •
$2.4955$ $\pm0.0023$ 2
VOUTSINAS
2020
$2.4952$ $\pm0.0023$
LEP-SLC
2006
${\it{}E}^{\it{}ee}_{\rm{}cm}$ = $88 - 94$ GeV
$2.4943$ $\pm0.0041$ 3
ABBIENDI
2004G
 OPAL ${\it{}E}^{\it{}ee}_{\rm{}cm}$= LEP1 + $130 - 209$ GeV
$2.4948$ $\pm0.0041$ 4.57M 4
ABBIENDI
2001A
 OPAL ${\it{}E}^{\it{}ee}_{\rm{}cm}$= $88 - 94$ GeV
$2.4876$ $\pm0.0041$ 4.08M 5
ABREU
2000F
 DLPH ${\it{}E}^{\it{}ee}_{\rm{}cm}$= $88 - 94$ GeV
$2.5024$ $\pm0.0042$ 3.96M 6
ACCIARRI
2000C
 L3 ${\it{}E}^{\it{}ee}_{\rm{}cm}$= $88 - 94$ GeV
$2.5025$ $\pm0.0041$ 3.97M 7
ACCIARRI
2000Q
 L3 ${\it{}E}^{\it{}ee}_{\rm{}cm}$= LEP1 + $130 - 189$ GeV
$2.4951$ $\pm0.0043$ 4.57M 8
BARATE
2000C
 ALEP ${\it{}E}^{\it{}ee}_{\rm{}cm}$= $88 - 94$ GeV
$2.50$ $\pm0.21$ $\pm0.06$ 9
ABREU
1996R
 DLPH ${\it{}E}^{\it{}ee}_{\rm{}cm}$= $91.2$ GeV
$3.8$ $\pm0.8$ $\pm1.0$ 188
ABE
1989C
 CDF ${\it{}E}^{\it{}p\overline{\it{}p}}_{\rm{}cm}$= $1.8$ TeV
$2.42$ ${}^{+0.45}_{-0.35}$ 480 10
ABRAMS
1989B
 MRK2 ${\it{}E}^{\it{}ee}_{\rm{}cm}$= $89 - 93$ GeV
$2.7$ ${}^{+1.2}_{-1.0}$ $\pm1.3$ 24 11
ALBAJAR
1989
UA1 ${\it{}E}^{\it{}p\overline{\it{}p}}_{\rm{}cm}$= 546,630 GeV
$2.7$ $\pm2.0$ $\pm1.0$ 25 12
ANSARI
1987
UA2 ${\it{}E}^{\it{}p\overline{\it{}p}}_{\rm{}cm}$= 546,630 GeV
1  JANOT 2020 applies a correction to LEP-SLC 2006 using an updated Bhabha cross section calculation. This result also includes a correction to account for correlated luminosity bias as presented in VOUTSINAS 2020 .
2  VOUTSINAS 2020 applies a correction to LEP-SLC 2006 to account for correlated luminosity bias.
3  ABBIENDI 2004G obtain this result using the S$-$matrix formalism for a combined fit to their cross section and asymmetry data at the ${{\mathit Z}}$ peak and their data at $130 - 209$ GeV. The authors have corrected the measurement for the 1 MeV shift with respect to the Breit$-$Wigner fits.
4  ABBIENDI 2001A error includes approximately $3.6$ MeV due to statistics, 1$~$MeV due to event selection systematics, and $1.3$ MeV due to LEP energy uncertainty.
5  The error includes $1.2$ MeV due to LEP energy uncertainty.
6  The error includes $1.3$ MeV due to LEP energy uncertainty.
7  ACCIARRI 2000Q interpret the $\mathit s$-dependence of the cross sections and lepton forward-backward asymmetries in the framework of the S-matrix formalism. They fit to their cross section and asymmetry data at high energies, using the results of S-matrix fits to ${{\mathit Z}}$-peak data (ACCIARRI 2000C) as constraints. The $130 - 189$ GeV data constrains the ${{\mathit \gamma}}/{{\mathit Z}}$ interference term. The authors have corrected the measurement for the $0.9$ MeV shift with respect to the Breit-Wigner fits.
8  BARATE 2000C error includes approximately $3.8$ MeV due to statistics, $0.9~$MeV due to experimental systematics, and $1.3~$MeV due to LEP energy uncertainty.
9  ABREU 1996R obtain this value from a study of the interference between initial and final state radiation in the process ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit Z}}$ $\rightarrow$ ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ .
10  ABRAMS 1989B uncertainty includes 50 MeV due to the miniSAM background subtraction error.
11  ALBAJAR 1989 result is from a total sample of 33 ${{\mathit Z}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ events.
12  Quoted values of ANSARI 1987 are from direct fit. Ratio of ${{\mathit Z}}$ and ${{\mathit W}}$ production gives either $\Gamma\mathrm {({{\mathit Z}})}$ $<$ ($1.09$ $\pm0.07$) ${\times }$ $\Gamma\mathrm {({{\mathit W}})}$, CL = 90$\%$ or $\Gamma\mathrm {({{\mathit Z}})}$ = ($0.82$ ${}^{+0.19}_{-0.14}$ $\pm0.06$) ${\times }$ $\Gamma\mathrm {({{\mathit W}})}$. Assuming Standard-Model value $\Gamma\mathrm {({{\mathit W}})}$ = 2.65 GeV then gives $\Gamma\mathrm {({{\mathit Z}})}$ $<$ $2.89$ $\pm0.19$ or = $2.17$ ${}^{+0.50}_{-0.37}$ $\pm0.16$.
References:
JANOT 2020
PL B803 135319 Improved Bhabha cross section at LEP and the number of light neutrino species
VOUTSINAS 2020
PL B800 135068 Beam-beam effects on the luminosity measurement at LEP and the number of light neutrino species
LEP-SLC 2006
PRPL 427 257 Precision Electroweak Measurements on the ${{\mathit Z}}$ Resonance
ABBIENDI 2004G
EPJ C33 173 Tests of the Standard Model and Constraints on New Physics from Measurements of Fermion Pair Production at 189 to 209 GeV at LEP
ABBIENDI 2001A
EPJ C19 587 Precise Determination of the ${{\mathit Z}}$ Resonance Parameters at LEP: “Zedometry''
ABREU 2000F
EPJ C16 371 Cross Sections and Leptonic Forward-Backward Asymmetries from the ${{\mathit Z}^{0}}$ Running of LEP
ACCIARRI 2000Q
PL B489 93 Determination of ${{\mathit \gamma}}/{{\mathit Z}}$ Interference in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Annihilation at LEP
ACCIARRI 2000C
EPJ C16 1 Measurements of Cross Sections and Forward Backward Asymmetries at the ${{\mathit Z}}$ Resonance and Determination of Electroweak Parameters
BARATE 2000C
EPJ C14 1 Measurement of the ${{\mathit Z}}$ Resonance Parameters at LEP
ABREU 1996R
ZPHY C72 31 First Study of the Interference between Initial and Final State Radiation at the ${{\mathit Z}}$ Resonance
ABE 1989C
PRL 63 720 Measurement of the Mass and Width of ${{\mathit Z}^{0}}$ Boson at the Fermilab Tevatron
ABRAMS 1989B
PRL 63 2173 Measurements of ${{\mathit Z}^{0}}$-Boson Resonance Parameters in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Annihilation
ALBAJAR 1989
ZPHY C44 15 Studies of Intermediate Vector Boson Production and Decay in UA1 at the CERN Proton-Antiproton Collider
ANSARI 1987
PL B186 440 Measurement of the Standard Model Parameters from a Study of ${{\mathit W}}$ and ${{\mathit Z}^{0}}$ Bosons