Constraints on Dark Matter Axion-Like-Particles with Inelastic Inverse Primakoff Interactions

Greeshma Chandrabhanu^1*, L.Singh^1,2, C.-P. Wu⁴, C.-P. Liu^5,3, J.-W. Chen^5,6, H.-C. Chi⁵, M.K. Pandey⁶, H.T. Wong¹

¹Institute of Physics, Academia Sinica, Taipei, Taiwan
²Department of Physics, Central University of South Bihar, Gaya, Bihar, India
³Physics Division,National Center for Theoretical Sciences, National Taiwan University, Taipei, Taiwan
⁴Département de Physique, Université de Montréal, Montréal, Canada
⁵Department of Physics, National Dong Hwa University, Shoufeng, Hualien, Taiwan
⁶Department of Physics,CTP and LeCosPA, National Taiwan University, Taipei, Taiwan

* Presenter:Greeshma Chandrabhanu, email:greeshmanew94@gmail.com

Axions are hypothetical particles first introduced in 1970s as a solution to the strong CP-problem. In recent years, there has been remarkable progress evolved from the original QCD axions to their variants generically called Axion-Like-Particles(ALPs). ALPs are well-motivated Dark Matter candidates which are naturally emerging in many extensions of Standard Model of particle physics. The coupling strength of axion with photons is given as g_aγγ . We extend the studies of ALPs with matter via inelastic Inverse Primakoff (IP) scattering to non-relativistic ALPs which are relevant to the case of DM [1]. The following three different data sets are selected to derive constraints on the (m _a , g_aγγ) parameter space:

1. TEXONO low threshold data with point-contact germanium detector from 300 eV _ee to 12 keV _ee[2].
2. TEXONO high energy (MeV _ee) reach data with high-purity germanium detector from 12 keV _ee to
3000 keV _ee [3].
3. XENON1T “S2-only” data with liquid xenon from 1.5 keV _ee to 207 keV _ee [4].

Elastic IP scattering with a single photon final state is the dominant channel for relativistic solar-ALPs. The detection efficiencies for single-hit events are close to unity at this low energy. TEXONO and XENON1T data are compatible with the background only hypothesis, and no excess of events are observed over background. Therefore, 90% C.L. exclusion limits for photon coupling strength of g_aγγ as a function of m_a is derived considering both IP _el and IP_ion cases. Based on the proposed DARWIN project, sensitivity bounds have been made by considering Single-Hit (SH) and ZERO Background cases. In DM-ALPs searches, new regions not accessible to other laboratory experiments are probed and excluded.

[1] C.-P. Wu et al., arXiv:2206.07878 [hep-ph]
[2] L. Singh et al. (TEXONO Collaboration), Phys. Rev. D 99, 032009 (2019).
[3] H. T. Wong et al. (TEXONO Collaboration), Phys. Rev. D 75, 012001 (2007).
[4] E. Aprile et al. (XENON Collaboration), Phys. Rev. D 102, 072004 (2020).

Keywords: Axions,, Dark Matter, , Inelastic Scattering