We report the results of an axion dark matter search over an axion mass range of <math><mrow><mn>9.39</mn><mi>–</mi><mn>9.51</mn><mtext> </mtext><mtext> </mtext><mi>μ</mi><mi>eV</mi></mrow></math>. A flux-driven Josephson parametric amplifier (JPA) was added to the cryogenic receiver chain. A system noise temperature of as low as 200 mK was achieved, which is the lowest recorded noise among published axion cavity experiments with phase-insensitive JPA operation. In addition, we developed a two-stage scanning method which boosted the scan speed by 26%. As a result, a range of two-photon coupling in a plausible model for the QCD axion was excluded with an order of magnitude higher in sensitivity than existing limits.

South Korea

Jinsu Kim

Ohjoon Kwon

Çağlar Kutlu

Woohyun Chung

Andrei Matlashov

Sergey Uchaikin

Japan

Arjan Ferdinand van Loo

Yasunobu Nakamura

Seonjeong Oh

HeeSu Byun

Danho Ahn

Yannis K. Semertzidis

Near-Quantum-Noise Axion Dark Matter Search at CAPP around <math><mrow><mrow><mn>9.5</mn><mtext> </mtext><mtext> </mtext><mi>μ</mi></mrow><mi>eV</mi></mrow></math>

We report an axion dark matter search at Dine-Fischler-Srednicki-Zhitnitskii sensitivity with the CAPP-12TB haloscope, assuming axions contribute 100% of the local dark matter density. The search excluded the axion-photon coupling <math><msub><mi>g</mi><mrow><mi>a</mi><mi>γ</mi><mi>γ</mi></mrow></msub></math> down to about <math><mn>6.2</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>16</mn></mrow></msup><mtext> </mtext><mtext> </mtext><mrow><msup><mrow><mi>GeV</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math> over the axion mass range between 4.51 and <math><mrow><mn>4.59</mn><mtext> </mtext><mtext> </mtext><mi>μ</mi><mi>eV</mi></mrow></math> at a 90% confidence level. The achieved experimental sensitivity can also exclude Kim-Shifman-Vainshtein-Zakharov axion dark matter that makes up just 13% of the local dark matter density. The CAPP-12TB haloscope will continue the search over a wide range of axion masses.

Andrew K. Yi

Saebyeok Ahn

JinMyeong Kim

Byeong Rok Ko

Boris I. Ivanov

Arjan F. van Loo

SeongTae Park

Junu Jeong

Sergey V. Uchaikin

Jihoon Choi

Soohyung Lee

MyeongJae Lee

Yun Chang Shin

Doyu Lee

SungJae Bae

Jiwon Lee

Younggeun Kim

Violeta Gkika

Ki Woong Lee

Taehyeon Seong

DongMin Kim

SungWoo Youn

Axion Dark Matter Search around <math><mrow><mn>4.55</mn><mtext> </mtext><mtext> </mtext><mi>μ</mi><mi>eV</mi></mrow></math> with Dine-Fischler-Srednicki-Zhitnitskii Sensitivity

The Center for Axion and Precision Physics Research at the Institute for Basic Science is searching for axion dark matter using ultralow temperature microwave resonators. We report the exclusion of the axion mass range <math><mrow><mn>10.7126</mn><mi>–</mi><mn>10.7186</mn><mtext> </mtext><mtext> </mtext><mi>μ</mi><mi>eV</mi></mrow></math> with near Kim-Shifman-Vainshtein-Zakharov (KSVZ) coupling sensitivity and the range <math><mrow><mn>10.16</mn><mi>–</mi><mn>11.37</mn><mtext> </mtext><mtext> </mtext><mi>μ</mi><mi>eV</mi></mrow></math> with about 9 times larger coupling at 90% confidence level. This is the first axion search result in these ranges. It is also the first with a resonator physical temperature of less than 40 mK.

CERN

France

Fritz Caspers

Hyoungsoon Choi

Yonuk Chong

Hoyong Jeong

Jihn E. Kim

Jihnhwan Lee

Seongtae Park

First Results from an Axion Haloscope at CAPP around <math><mrow><mrow><mn>10.7</mn><mtext> </mtext><mtext> </mtext><mi>μ</mi><mi>eV</mi></mrow></mrow></math>