Search for ${{\mathit X}^{0}}$ Resonance in ${{\mathit Z}}$ $\rightarrow$ ${{\mathit f}}{{\overline{\mathit f}}}{{\mathit X}^{0}}$

The limit is for B( ${{\mathit Z}}$ $\rightarrow$ ${{\mathit f}}{{\overline{\mathit f}}}{{\mathit X}^{0}}$) $\cdot{}$ B( ${{\mathit X}^{0}}$ $\rightarrow$ ${{\mathit F}}$) where ${{\mathit f}}$ is a fermion and ${{\mathit F}}$ is the specified final state. Spin$~$0 is assumed for ${{\mathit X}^{0}}$.
VALUE CL% DOCUMENT ID TECN  COMMENT
• • We do not use the following data for averages, fits, limits, etc. • •
1
 1996 T
DLPH $\mathit f={{\mathit e}},{{\mathit \mu}},{{\mathit \tau}}$; $\mathit F={{\mathit \gamma}}{{\mathit \gamma}}$
$<3.7 \times 10^{-6}$ 95 2
 1996 T
DLPH $\mathit f={{\mathit \nu}}$; $\mathit F={{\mathit \gamma}}{{\mathit \gamma}}$
3
 1996 T
DLPH $\mathit f={{\mathit q}}$; $\mathit F={{\mathit \gamma}}{{\mathit \gamma}}$
$<6.8 \times 10^{-6}$ 95 2
 1993 E
OPAL ${{\mathit f}}={{\mathit e}},{{\mathit \mu}},{{\mathit \tau}}$; ${{\mathit F}}={{\mathit \gamma}}{{\mathit \gamma}}$
$<5.5 \times 10^{-6}$ 95 2
 1993 E
OPAL ${{\mathit f}}={{\mathit q}}$; ${{\mathit F}}={{\mathit \gamma}}{{\mathit \gamma}}$
$<3.1 \times 10^{-6}$ 95 2
 1993 E
OPAL ${{\mathit f}}={{\mathit \nu}}$; ${{\mathit F}}={{\mathit \gamma}}{{\mathit \gamma}}$
$<6.5 \times 10^{-6}$ 95 2
 1993 E
OPAL ${{\mathit f}}={{\mathit e}},{{\mathit \mu}}$; ${{\mathit F}}={{\mathit \ell}}{{\overline{\mathit \ell}}}$, ${{\mathit q}}{{\overline{\mathit q}}}$, ${{\mathit \nu}}{{\overline{\mathit \nu}}}$
$<7.1 \times 10^{-6}$ 95 2
 1993 F
ALEP ${{\mathit f}}={{\mathit e}},{{\mathit \mu}}$; ${{\mathit F}}={{\mathit \ell}}{{\overline{\mathit \ell}}}$, ${{\mathit q}}{{\overline{\mathit q}}}$, ${{\mathit \nu}}{{\overline{\mathit \nu}}}$
4
 1992 F
L3 ${{\mathit f}}={{\mathit q}}$; ${{\mathit F}}={{\mathit \gamma}}{{\mathit \gamma}}$
 1 ABREU 1996T obtain limit as a function of ${\mathit m}_{{{\mathit X}^{0}}}$. See their Fig.$~$6.
 2 Limit is for ${\mathit m}_{{{\mathit X}^{0}}}$ around 60 GeV.
 3 ABREU 1996T obtain limit as a function of ${\mathit m}_{{{\mathit X}^{0}}}$. See their Fig.$~$15.
 4 ADRIANI 1992F give ${{\mathit \sigma}_{{{Z}}}}\cdot{}$B( ${{\mathit Z}}$ $\rightarrow$ ${{\mathit q}}{{\overline{\mathit q}}}{{\mathit X}^{0}}$) $\cdot{}$ B( ${{\mathit X}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}})<(0.75 - 1.5)~$pb (95$\%$CL) for ${\mathit m}_{{{\mathit X}^{0}}}$ = $10 - 70$ GeV. The limit is 1$~$pb at 60 GeV.
References