Search for invisible axion dark matter of mass <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">m</mml:mi></mml:mrow><mml:mrow><mml:mi>a</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mn>43</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>μ</mml:mi><mml:mi>eV</mml:mi></mml:mrow></mml:math> with the QUAX–<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>a</mml:mi><mml:mi>γ</mml:mi></mml:math> experiment
D. Alesini, C. Braggio, G. Carugno, N. Crescini, D. D’Agostino, D. Di Gioacchino, R. Di Vora, P. Falferi, U. Gambardella, C. Gatti, G. Iannone, C. Ligi, A. Lombardi, G. Maccarrone, A. Ortolan, R. Pengo, A. Rettaroli, G. Ruoso, L. Taffarello, S. Tocci
Abstract
A haloscope of the QUAX--$a\ensuremath{\gamma}$ experiment composed of an oxygen-free high thermal conductivity-Cu cavity inside an 8.1 T magnet and cooled to $\ensuremath{\sim}200\text{ }\text{ }\mathrm{mK}$ is put in operation for the search of galactic axion with mass ${m}_{a}\ensuremath{\simeq}43\text{ }\text{ }\ensuremath{\mu}\mathrm{eV}$. The power emitted by the resonant cavity is amplified with a Josephson parametric amplifier whose noise fluctuations are at the standard quantum limit. With the data collected in about 1 h at the cavity frequency ${\ensuremath{\nu}}_{c}=10.40176\text{ }\text{ }\mathrm{GHz}$, the experiment reaches the sensitivity necessary for the detection of galactic QCD-axion, setting the 90% confidence level limit to the axion-photon coupling ${g}_{a\ensuremath{\gamma}\ensuremath{\gamma}}<0.766\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}\text{ }\text{ }{\mathrm{GeV}}^{\ensuremath{-}1}$.