# MASS LIMITS for a Heavy Neutral Boson Coupling to ${{\boldsymbol e}^{+}}{{\boldsymbol e}^{-}}$ INSPIRE search

VALUE (GeV) CL% DOCUMENT ID TECN  COMMENT
• • • We do not use the following data for averages, fits, limits, etc. • • •
$\text{none 55-61}$ 1
 1989
VNS $\Gamma\mathrm {( {{\mathit X}^{0}} \rightarrow {{\mathit e}^{+}} {{\mathit e}^{-}} )}$ $\cdot{}$ B( ${{\mathit X}^{0}}$ $\rightarrow$ had.)${ {}\gtrsim{} }$0.2 MeV
$>45$ 95 2
 1986
HRS $\Gamma\mathrm {( {{\mathit X}^{0}} \rightarrow {{\mathit e}^{+}} {{\mathit e}^{-}} )}$=6 MeV
$>46.6$ 95 3
 1985
MRKJ $\Gamma\mathrm {( {{\mathit X}^{0}} \rightarrow {{\mathit e}^{+}} {{\mathit e}^{-}} )}$=10 keV
$>48$ 95 3
 1985
MRKJ $\Gamma\mathrm {( {{\mathit X}^{0}} \rightarrow {{\mathit e}^{+}} {{\mathit e}^{-}} )}$=4 MeV
4
 1985 B
PLUT
$\text{none 39.8 - 45.5}$ 5
 1984
MRKJ $\Gamma\mathrm {( {{\mathit X}^{0}} \rightarrow {{\mathit e}^{+}} {{\mathit e}^{-}} )}$=10 keV
$>47.8$ 95 5
 1984
MRKJ $\Gamma\mathrm {( {{\mathit X}^{0}} \rightarrow {{\mathit e}^{+}} {{\mathit e}^{-}} )}$=4 MeV
$\text{none 39.8 - 45.2}$ 5
 1984 C
CELL
$>47$ 95 5
 1984 C
CELL $\Gamma\mathrm {( {{\mathit X}^{0}} \rightarrow {{\mathit e}^{+}} {{\mathit e}^{-}} )}$=4 MeV
1  ODAKA 1989 looked for a narrow or wide scalar resonance in ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ hadrons at $\mathit E_{{\mathrm {cm}}}$ = $55.0-60.8$ GeV.
2  DERRICK 1986 found no deviation from the Standard Model Bhabha scattering at $\mathit E_{{\mathrm {cm}}}$= 29 GeV and set limits on the possible scalar boson ${{\mathit e}^{+}}{{\mathit e}^{-}}$ coupling. See their figure 4 for excluded region in the $\Gamma\mathrm {( {{\mathit X}^{0}} \rightarrow {{\mathit e}^{+}} {{\mathit e}^{-}} )}-{\mathit m}_{{{\mathit X}^{0}}}$ plane. Electronic chiral invariance requires a parity doublet of ${{\mathit X}^{0}}$, in which case the limit applies for $\Gamma\mathrm {( {{\mathit X}^{0}} \rightarrow {{\mathit e}^{+}} {{\mathit e}^{-}} )}$ = 3 MeV.
3  ADEVA 1985 first limit is from 2${{\mathit \gamma}}$, ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ , hadrons assuming ${{\mathit X}^{0}}$ is a scalar. Second limit is from ${{\mathit e}^{+}}{{\mathit e}^{-}}$ channel. $\mathit E_{{\mathrm {cm}}}$ = 40$-$47 GeV. Supersedes ADEVA 1984 .
4  BERGER 1985B looked for effect of spin-0 boson exchange in ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ and ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ at $\mathit E_{{\mathrm {cm}}}$ = $34.7$ GeV. See Fig.$~$5 for excluded region in the ${\mathit m}_{{{\mathit X}^{0}}}−\Gamma\mathrm {({{\mathit X}^{0}})}$ plane.
5  ADEVA 1984 and BEHREND 1984C have $\mathit E_{{\mathrm {cm}}}$ = 39.8$-$45.5 GeV. MARK-J searched ${{\mathit X}^{0}}$ in ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ hadrons, 2${{\mathit \gamma}}$, ${{\mathit \mu}^{+}}{{\mathit \mu}^{-}}$ , ${{\mathit e}^{+}}{{\mathit e}^{-}}$ and CELLO in the same channels plus ${{\mathit \tau}}$ pair. No narrow or broad ${{\mathit X}^{0}}$ is found in the energy range. They also searched for the effect of ${{\mathit X}^{0}}$ with ${\mathit m}_{{{\mathit X}}}$ $>\mathit E_{{\mathrm {cm}}}$. The second limits are from Bhabha data and for spin-0 singlet. The same limits apply for $\Gamma\mathrm {( {{\mathit X}^{0}} \rightarrow {{\mathit e}^{+}} {{\mathit e}^{-}} )}$ = 2 MeV if ${{\mathit X}^{0}}$ is a spin-0 doublet. The second limit of BEHREND 1984C was read off from their figure 2. The original papers also list limits in other channels.
References:
 ODAKA 1989
JPSJ 58 3037 New Limits on Neutral Scalar Bosons
 DERRICK 1986
PL 166B 463 New Results from Bhabha Scattering at 29 GeV
 ADEVA 1985
PL 152B 439 New Particles Searches
 BERGER 1985B
ZPHY C27 341 Tests of the Standard Model with Lepton Pair Production in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Reactions
 ADEVA 1984
PRL 53 134 Search for New Particles in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Annihilation from 39.79 to 45.52 GeV
 BEHREND 1984C
PL 140B 130 Limits on Spin 0 Bosons in ${{\mathit e}^{+}}{{\mathit e}^{-}}$ Annihilation up to 45.2 GeV $\mathit E_{{\mathrm {cm}}}$