Search for ${{\mathit X}^{0}}$ Resonance in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Collisions

INSPIRE   PDGID:
S056REE
The limit is for $\Gamma\mathrm {( {{\mathit X}^{0}} \rightarrow {{\mathit e}^{+}} {{\mathit e}^{-}} )}$ $\cdot{}$ B( ${{\mathit X}^{0}}$ $\rightarrow$ ${{\mathit f}}$ ), where ${{\mathit f}}$ is the specified final state. Spin$~$0 is assumed for ${{\mathit X}^{0}}$.
VALUE (keV) CL% DOCUMENT ID TECN  COMMENT
• • We do not use the following data for averages, fits, limits, etc. • •
$<10^{3}$ 95 1
ABE
1993C
 VNS $\Gamma\mathrm {( {{\mathit e}} {{\mathit e}} )}$
$\text{<(0.4 - 10)}$ 95 2
ABE
1993C
 VNS ${{\mathit f}}$ = ${{\mathit \gamma}}{{\mathit \gamma}}$
$\text{<(0.3 - 5)}$ 95 3, 4
ABE
1993D
 TOPZ ${{\mathit f}}$ = ${{\mathit \gamma}}{{\mathit \gamma}}$
$\text{<(2 - 12)}$ 95 3, 4
ABE
1993D
 TOPZ ${{\mathit f}}$ = hadrons
$\text{<(4 - 200)}$ 95 5, 4
ABE
1993D
 TOPZ ${{\mathit f}}$ = ${{\mathit e}}{{\mathit e}}$
$\text{<(0.1 - 6)}$ 95 5, 4
ABE
1993D
 TOPZ ${{\mathit f}}$ = ${{\mathit \mu}}{{\mathit \mu}}$
$\text{<(0.5 - 8)}$ 90 6
STERNER
1993
AMY ${{\mathit f}}$ = ${{\mathit \gamma}}{{\mathit \gamma}}$
1  Limit is for $\Gamma\mathrm {( {{\mathit X}^{0}} \rightarrow {{\mathit e}^{+}} {{\mathit e}^{-}} )}{\mathit m}_{{{\mathit X}^{0}}}$ = $56 - 63.5$ GeV for $\Gamma\mathrm {({{\mathit X}^{0}})}$ = $0.5$ GeV.
2  Limit is for ${\mathit m}_{{{\mathit X}^{0}}}$ = $56 - 61.5$ GeV and is valid for $\Gamma\mathrm {({{\mathit X}^{0}})}{}\ll$100 MeV. See their Fig.$~$5 for limits for $\Gamma $ = 1,2 GeV.
3  Limit is for ${\mathit m}_{{{\mathit X}^{0}}}$ = $57.2 - 60$ GeV.
4  Limit is valid for $\Gamma\mathrm {({{\mathit X}^{0}})}{}\ll$100 MeV. See paper for limits for $\Gamma $ = 1 GeV and those for $\mathit J = 2$ resonances.
5  Limit is for ${\mathit m}_{{{\mathit X}^{0}}}$ = $56.6 - 60$ GeV.
6  STERNER 1993 limit is for ${\mathit m}_{{{\mathit X}^{0}}}$ = $57 - 59.6$ GeV and is valid for $\Gamma\mathrm {({{\mathit X}^{0}})}<$100 MeV. See their Fig.$~$2 for limits for $\Gamma $ = 1,3 GeV.
References:
ABE 1993D
PL B304 373 Search for a Narrow Resonance in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Collisions between $\mathit E_{{\mathrm {cm}}}$ = 58 and 60 GeV
ABE 1993C
PL B302 119 Search for Heavy Neutral Spinless Particles Using ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ and ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$ Reactions in $\mathit E_{{\mathrm {cm}}}$ Range between 54 and 64 GeV
STERNER 1993
PL B303 385 Search for Anomalous ${{\mathit \gamma}}{{\mathit \gamma}}$ Production at TRISTAN