# ${{\boldsymbol A}^{0}}$ (Axion) Searches in Reactor Experiments INSPIRE search

VALUE DOCUMENT ID TECN  COMMENT
• • • We do not use the following data for averages, fits, limits, etc. • • •
1
 2007
Primakoff or Compton
2
 1995
CNTR Reactor; ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$
3
 1986
SPEC Reactor, ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$
4
 1986
SPEC Reactor; ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$
5
 1982
CNTR Light water reactor
6
 1981
CNTR Reactor, ${{\mathit A}^{0}}$ $\rightarrow$ 2 ${{\mathit \gamma}}$
1  CHANG 2007 looked for monochromatic photons from Primakoff or Compton conversion of axions from the Kuo-Sheng reactor due to axion coupling to photon or electron, respectively. The search places model-independent limits on the products $\mathit G_{ {{\mathit A}} {{\mathit \gamma}} {{\mathit \gamma}} }\mathit G_{ {{\mathit A}} {{\mathit N}} {{\mathit N}} }$ and $\mathit G_{ {{\mathit A}} {{\mathit e}} {{\mathit e}} }\mathit G_{ {{\mathit A}} {{\mathit N}} {{\mathit N}} }$ for $\mathit m({{\mathit A}^{0}}$) less than the MeV range.
2  ALTMANN 1995 looked for ${{\mathit A}^{0}}$ decaying into ${{\mathit e}^{+}}{{\mathit e}^{-}}$ from the Bugey$~$5 nuclear reactor. They obtain an upper limit on the ${{\mathit A}^{0}}$ production rate of $\omega ({{\mathit A}^{0}})/\omega ({{\mathit \gamma}}$) ${\times }$B( ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit e}^{+}}{{\mathit e}^{-}}$ )$<10^{-16}$ for ${\mathit m}_{{{\mathit A}^{0}}}$ = $1.5$ MeV at 90$\%$ CL. The limit is weaker for heavier ${{\mathit A}^{0}}$. In the case of a standard axion, this limit excludes a mass in the range 2${\mathit m}_{{{\mathit e}}}<{\mathit m}_{{{\mathit A}^{0}}}<4.8$ MeV at 90$\%$ CL. See Fig.$~$5 of their paper for exclusion limits of axion-like resonances ${{\mathit Z}^{0}}$ in the (${\mathit m}_{{{\mathit X}^{0}}},\mathit f_{{{\mathit X}^{0}}}$) plane.
3  KETOV 1986 searched for ${{\mathit A}^{0}}$ at the Rovno nuclear power plant. They found an upper limit on the ${{\mathit A}^{0}}$ production probability of 0.8 $\lbrack{}$100 keV/${\mathit m}_{{{\mathit A}^{0}}}\rbrack{}{}^{6}{\times }10^{-6}$ per fission. In the standard axion model, this corresponds to ${\mathit m}_{{{\mathit A}^{0}}}$ $>$150 keV. Not valid for ${\mathit m}_{{{\mathit A}^{0}}}{ {}\gtrsim{} }$ 1 MeV.
4  KOCH 1986 searched for ${{\mathit A}^{0}}$ $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$ at nuclear power reactor Biblis A. They found an upper limit on the ${{\mathit A}^{0}}$ production rate of $\omega ({{\mathit A}^{0}})/\omega ({{\mathit \gamma}}(\mathit M$1)) $<$ $1.5 \times 10^{-10}$ (CL=95$\%$). Standard axion with ${\mathit m}_{{{\mathit A}^{0}}}$ = 250 keV gives $10^{-5}$ for the ratio. Not valid for ${\mathit m}_{{{\mathit A}^{0}}}$ $>$1022 keV.
5  DATAR 1982 looked for ${{\mathit A}^{0}}$ $\rightarrow$ 2 ${{\mathit \gamma}}$ in neutron capture ( ${{\mathit n}}$ ${{\mathit p}}$ $\rightarrow$ ${{\mathit d}}{{\mathit A}^{0}}$ ) at Tarapur 500 MW reactor. Sensitive to sum of $\mathit I = 0$ and $\mathit I = 1$ amplitudes. With ZEHNDER 1981 $\lbrack{}(\mathit I = 0$) $–$ ($\mathit I = 1)\rbrack{}$ result, assert nonexistence of standard ${{\mathit A}^{0}}$.
6  VUILLEUMIER 1981 is at Grenoble reactor. Set limit ${\mathit m}_{{{\mathit A}^{0}}}$ $<$280 keV.
References:
 CHANG 2007
PR D75 052004 Search for Axions from the Kuo-Sheng Nuclear Power Reactor with a High-Purity Germanium Detector
 ALTMANN 1995
ZPHY C68 221 Search for the Electron Positron Decay of Axions and Axion-Like Particles at a Nuclear Power Reactor at Bugey
 KETOV 1986
JETPL 44 146 Search for Unusual Events in a Flux of Reactor Antineutrinos
 KOCH 1986
NC 96A 182 Search for Axions at the Nuclear Power Reactor Biblis-A
 DATAR 1982
PL 114B 63 Search for Axions in the Thermal Neutron Capture by Protons
 VUILLEUMIER 1981
PL 101B 341 An Experimental Limit on Production of Axions in a Fission Reactor