CAST Collaboration, E. Arik, S. Aune, D. Autiero, K. Barth, A. Belov, B. Beltrán, S. Borghi, G. Bourlis, F. S. Boydag, H. Bräuninger, J. M. Carmona, S. Cebrián,… 展开作者
CAST Collaboration, E. Arik, S. Aune, D. Autiero, K. Barth, A. Belov, B. Beltrán, S. Borghi, G. Bourlis, F. S. Boydag, H. Bräuninger, J. M. Carmona, S. Cebrián, S. A. Cetin, J. I. Collar, T. Dafni, M. Davenport, L. Di Lella, O. B. Dogan, C. Eleftheriadis, N. Elias, G. Fanourakis, E. Ferrer-Ribas, H. Fischer, P. Friedrich, J. Franz, J. Galán, T. Geralis, I. Giomataris, S. Gninenko, H. Gómez, R. Hartmann, M. Hasinoff, F. H. Heinsius, I. Hikmet, D. H. H. Hoffmann, I. G. Irastorza, J. Jacoby, K. Jakovčić, D. Kang, K. Königsmann, R. Kotthaus, M. Krčmar, K. Kousouris, M. Kuster, B. Lakić, C. Lasseur, A. Liolios, A. Ljubičić, G. Lutz, G. Luzón, D. Miller, J. Morales, T. Niinikoski, A. Nordt, A. Ortiz, T. Papaevangelou, M. J. Pivovaroff, A. Placci, G. Raffelt, H. Riege, A. Rodríguez, J. Ruz, I. Savvidis, Y. Semertzidis, P. Serpico, R. Soufli, L. Stewart, K. van Bibber, J. Villar, J. Vogel, L. Walckiers, K. Zioutas
备注：
18 pages, 7 figures. Revised version of the paper after referee's comments. Main changes on the gas section
We have searched for solar axions or other pseudoscalar particles that couple to two photons by using the CERN Axion Solar Telescope (CAST) setup. Whereas we previously have reported results from CAST with evacuated magnet bores (Phase I), setting limits on lower mass axions, here we report results from CAST where the magnet bores were filled with \hefour gas (Phase II) of variable pressure. The introduction of gas generated a refractive photon mass $m_γ$, thereby achieving the maximum possible conversion rate for those axion masses \ma that match $m_γ$. With 160 different pressure settings we have scanned \ma up to about 0.4 eV, taking approximately 2 h of data for each setting. From the absence of excess X-rays when the magnet was pointing to the Sun, we set a typical upper limit on the axion-photon coupling of $\gag\lesssim 2.17\times 10^{-10} {\rm GeV}^{-1}$ at 95% CL for $\ma \lesssim 0.4$ eV, the exact result depending on the pressure setting. The excluded parameter range covers realistic axion models with a Peccei-Quinn scale in the neighborhood of $f_{\rm a}\sim10^{7}$ GeV. Currently in the second part of CAST Phase II, we are searching for axions with masses up to about 1.2 eV using \hethree as a buffer gas.
本文介绍了欧洲核子研究中心（CERN）的轴子太阳望远镜（CAST）和轴子暗物质实验（ADMX）的研究结果，并简要评述了利用各种实验技术进行轴子搜索的前景。CAST已经探索了高达0.64 eV的质量，对轴子-光子耦合设置了最严格的限制，除了ADMX是最具竞争力的实验的微eV区域。CAST的目标是超过1 eV WMAP的上限，并可能使用额外灵敏的X射线探测器重新审视真空中的操作，而ADMX使用改进的额外灵敏的SQUID放大器将探索微电子伏特的质量范围。
We present results of the Relic Axion Dark-Matter Exploratory Setup (RADES), a detector which is part of the CERN Axion Solar Telescope (CAST), searching for axion dark matter in the 34.67$μ$eV mass range. A radio frequency cavity consisting of 5 sub-cavities coupled by inductive irises took physics data inside the CAST dipole magnet for the first time using this filter-like haloscope geometry. An exclusion limit with a 95% credibility level on the axion-photon coupling constant of g$_{aγ}\gtrsim 4\times10^{-13} \text{GeV}^{-1}$ over a mass range of 34.6738 $μ$eV < $m_a$ < 34.6771 $μ$eV is set…
The CAST-CAPP axion haloscope, operating at CERN inside the CAST dipole magnet, has searched for axions in the 19.74 $μ$eV to 22.47 $μ$eV mass range. The detection concept follows the Sikivie haloscope principle, where Dark Matter axions convert into photons within a resonator immersed in a magnetic field. The CAST-CAPP resonator is an array of four individual rectangular cavities inserted in a strong dipole magnet, phase-matched to maximize the detection sensitivity. Here we report on the data acquired for 4124 h from 2019 to 2021. Each cavity is equipped with a fast frequency tuning mechanis…
We propose a new scenario of using the dark axion portal at one-loop level to explain the recently observed muon anomalous magnetic moment by the Fermilab Muon g-2 experiment. Both axion/axion-like particle (ALP) and dark photon are involved in the same vertex with photon. Although ALP or dark photon alone cannot explain muon $g-2$, since the former provides only negative contribution while the latter has very much constrained parameter space, dark axion portal can save the situation and significantly extend the allowed parameter space. The observed muon anomalous magnetic moment provides a ro…
The Relic Axion Detector Experimental Setup (RADES) is an axion search project that uses a microwave filter as resonator for Dark Matter conversion. The main focus of this publication is the description of the 3 different cavity prototypes of RADES. The result of the first tests of one of the prototypes is also presented. The filters consist of 5 or 6 stainless steel sub-cavities joined by rectangular irises. The size of the sub-cavities determines the working frequency, the amount of sub-cavities determine the working volume. The first cavity prototype was built in 2017 to work at a frequency…
During 2003--2015, the CERN Axion Solar Telescope (CAST) has searched for $a\toγ$ conversion in the 9 T magnetic field of a refurbished LHC test magnet that can be directed toward the Sun. In its final phase of solar axion searches (2013--2015), CAST has returned to evacuated magnet pipes, which is optimal for small axion masses. The absence of a significant signal above background provides a world leading limit of $g_{aγ} < 0.66 \times 10^{-10} {\rm GeV}^{-1}$ (95% C.L.) on the axion-photon coupling strength for $m_a \lesssim 0.02$ eV. Compared with the first vacuum phase (2003--2004), the se…
A hypothetical pseudo-scalar particle axion, which is an immediate result of the Peccei-Quinn solution to the strong CP problem, may couple to gluons and lead to an oscillating electric dipole moment (EDM) of fundamental particles. This paper proposes a novel method of probing the axion-induced oscillating EDM in storage rings, using a radiofrequency (RF) Wien Filter. The Wien Filter at the frequency of the sidebands of the axion and $g-2$ frequency, $f_\text{axion} \pm f_{g-2}$, generates a spin resonance in the presence of an oscillating EDM, as confirmed both by an analytical estimation of …
A finite axion-nucleon coupling, nearly unavoidable for QCD axions, leads to the production of axions via the thermal excitation and subsequent de-excitation of Fe-57 isotopes in the sun. We revise the solar bound on this flux adopting the up to date emission rate, and investigate the sensitivity of the proposed International Axion Observatory IAXO and its intermediate stage BabyIAXO to detect these axions. We compare different realistic experimental options and discuss the model dependence of the signal. Already BabyIAXO has sensitivity far beyond previous solar axion searches via the nucleon…
Emission of relativistic axions from transient sources, such as axion star explosions, can lead to observable signatures. We show that axion bursts from collapsing axion stars can be detectable over the wide range of axion masses $10^{-15} \, \textrm{eV} \lesssim m \lesssim 10^{-7} \, \textrm{eV}$ in laboratory experiments, such as ABRACADABRA, DMRadio and SHAFT. The detection of axion bursts could provide new insights into the fundamental axion potential, which is challenging to probe otherwise. An ensemble of bursts in the distant past would give rise to a diffuse axion background distinct f…
The most compelling candidates for Dark Matter to day are WIMPs and axions. The applicability of gasesous Time Projection Chambers (TPCs) with Micromesh Gas Structures (Micromegas) to the search of these particles is explored within this work. Both particles would produce an extremely low rate at very low energies in particle detectors. Micromegas detectors can provide both low background rates and low en- ergy threshold, due to the high granularity, radiopurity and uniformity of the readout. Small (few cm wide) Micromegas detectors are used to image the axion-induced x-ray signal expected in …
We investigate the 5.49 MeV solar axions flux produced in the $p(d,\, ^{3}{\rm He})a$ reaction and analyze the potential to detect it with the forthcoming large underground neutrino oscillation experiment Jiangmen Underground Neutrino Observatory (JUNO). The JUNO detector could reveal axions through various processes such as Compton and inverse Primakoff conversion, as well as through their decay into two photons or electron-positron pairs inside the detector. We perform a detailed numerical analysis in order to forecast the sensitivity on different combinations of the axion-electron ($ g_{ae}…
We propose an experiment for detecting Axion-Like Particles (ALPs) based on the axion-photon interaction in the presence of a non-uniform magnetic field. The impact of virtual ALPs on the polarization of the photons inside a cavity is studied and a detection scheme is proposed. We find that the cavity normal modes are dispersed differently owing to their coupling to the ALPs in the presence of a background magnetic field. This birefringence, in turn, can be observed as a phase difference between the cavity polarization modes. The signal is considerably enhanced for a squeezed light source. We …
Probing the axion-electron coupling at cavity experiments
Pusan National University（釜山国立大学）；Extreme Physics Institute, Pusan National University（釜山国立大学极端物理研究所）；Center for Theoretical Physics of the Universe, Institute for Basic Science (IBS)（基础科学研究院宇宙理论物理中心）；Institute for Basic Science (IBS)（基础科学研究院）；School of Physics, Korea Institute for Advanced Study（韩国高等研究院物理学院）
We study charged lepton flavor violation associated with a light leptophilic axion-like particle (ALP), $X$, at the $B$-factory experiment Belle II. We focus on production of the ALP in the tau decays $τ\to X l$ with $l=e,μ$, followed by its decay via $X\to l^- l^+$. The ALP can be either promptly decaying or long-lived. We perform Monte-Carlo simulations, recasting a prompt search at Belle for lepton-flavor-violating $τ$ decays, and propose a displaced-vertex (DV) search. For both types of searches, we derive the Belle~II sensitivity reaches in both the product of branching fractions and the …
Probing 5.49 MeV Solar Axions at Xenon Experiments
Southeast University（东南大学）；Tsung-Dao Lee Institute & School of Physics and Astronomy, Shanghai Jiao Tong University（李政道研究所与上海交大物理与天文学院）；Shanghai Jiao Tong University（上海交通大学）；Peking University（北京大学）
Lowering the background level and the energy threshold of Micromegas x-ray detectors for axion searches
轴子太阳窥镜通过在强磁场中转换为x射线来寻找太阳轴子。使用低背景X射线探测器是提高这些搜索灵敏度的一个重要组成部分。本文综述了用于欧洲核子研究中心（CERN）轴子太阳望远镜（CAST）和未来国际轴子天文台（IAXO）的Micromegas探测器的最新进展。CAST中的实际设置已实现低于10 $^{-6}$ keV $^{-1}$ cm $^{-2}$ s $^{-1}$的本底水平，比第一代Micromegas探测器低100倍。这种减少是基于主动和被动屏蔽技术，选择放射纯材料，离线歧视技术和读出的高粒度。我们详细描述的背景模型的检测器，其操作的基础上在CAST网站和Canfranc地下实验室（LSC），以及Geant 4模拟。目前在LSC达到的最佳水平低于10 $^{-7}$ keV $^{-1}$ cm $^{-2}$ s $^{-1}$，并显示出该技术在IAO中应用的良好前景。最后，我们提出了一些想法和结果，降低这些探测器的能量阈值低于1千电子伏，使用高透明的窗口，自动触发电子学和研究在不同的能量的集群形状。由于在这个能量范围内预期会有高通量的类轴子粒子，亚千电子伏阈值探测器可以扩大轴子太阳镜的物理情况。
Probing keV mass QCD axions with the SACLA X-ray free electron laser
University of Oxford（牛津大学）；STFC Rutherford Appleton Laboratory（STFC卢瑟福阿普尔顿实验室）；RIKEN SPring-8 Center（理化学研究所SPring-8中心）；The University of Tokyo（东京大学）；European XFEL（欧洲X射线自由电子激光装置）；Japan Synchrotron Radiation Research Institute（日本同步辐射研究机构）；Tohoku University（东北大学）；University of Strathclyde（思克莱德大学）
We investigate the prospect of an alternative laboratory-based search for the coupling of axions and axion-like particles to photons. Here, the collision of two laser beams resonantly produces axions, and a signal photon is detected after magnetic reconversion, as in light-shining-through-walls (LSW) experiments. Conventional searches, such as LSW or anomalous birefrigence measurements, are most sensitive to axion masses for which substantial coherence can be achieved; this is usually well below optical energies. We find that using currently available high-power laser facilities, the bounds th…
