Search for the Pair Production of Dark Particles X with K_{L}^{0}→XX, X→γγ

C Lin; J K Ahn; J M Choi; M S Farrington; M Gonzalez; N Grethen; Y B Hsiung; T Inagaki; I Kamiji; E J Kim; J L Kim; H M Kim; K Kawata; A Kitagawa; T K Komatsubara; K Kotera; S K Lee; J W Lee; G Y Lim; Y Luo; T Matsumura; K Nakagiri; H Nanjo; T Nomura; K Ono; J C Redeker; T Sato; V Sasse; T Shibata; N Shimizu; T Shinkawa; S Shinohara; K Shiomi; R Shiraishi; S Suzuki; Y Tajima; Y-C Tung; Y W Wah; H Watanabe; T Wu; T Yamanaka; H Y Yoshida; KOTO Collaboration

doi:10.1103/PhysRevLett.130.111801

Search for the Pair Production of Dark Particles X with K_{L}^{0}→XX, X→γγ

Phys Rev Lett. 2023 Mar 17;130(11):111801. doi: 10.1103/PhysRevLett.130.111801.

Authors

C Lin¹, J K Ahn², J M Choi², M S Farrington¹, M Gonzalez³, N Grethen¹, Y B Hsiung⁴, T Inagaki⁵, I Kamiji⁶, E J Kim⁷, J L Kim⁷, H M Kim⁷, K Kawata³, A Kitagawa³, T K Komatsubara^{5

8}, K Kotera³, S K Lee⁷, J W Lee², G Y Lim^{5

8}, Y Luo¹, T Matsumura⁹, K Nakagiri⁶, H Nanjo³, T Nomura^{5

8}, K Ono³, J C Redeker¹, T Sato⁵, V Sasse¹, T Shibata³, N Shimizu³, T Shinkawa⁹, S Shinohara⁶, K Shiomi^{5

8}, R Shiraishi³, S Suzuki¹⁰, Y Tajima¹¹, Y-C Tung⁴, Y W Wah¹, H Watanabe^{5

8}, T Wu⁴, T Yamanaka³, H Y Yoshida¹¹; KOTO Collaboration

Affiliations

¹ Enrico Fermi Institute, University of Chicago, Chicago, Illinois 60637, USA.
² Department of Physics, Korea University, Seoul 02841, Republic of Korea.
³ Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan.
⁴ Department of Physics, National Taiwan University, Taipei, Taiwan 10617, Republic of China.
⁵ Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan.
⁶ Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
⁷ Division of Science Education, Jeonbuk National University, Jeonju 54896, Republic of Korea.
⁸ J-PARC Center, Tokai, Ibaraki 319-1195, Japan.
⁹ Department of Applied Physics, National Defense Academy, Kanagawa 239-8686, Japan.
¹⁰ Department of Physics, Saga University, Saga 840-8502, Japan.
¹¹ Department of Physics, Yamagata University, Yamagata 990-8560, Japan.

PMID: 37001070
DOI: 10.1103/PhysRevLett.130.111801

Abstract

We present the first search for the pair production of dark particles X via K_{L}^{0}→XX with X decaying into two photons using the data collected by the KOTO experiment. No signal was observed in the mass range of 40-110 MeV/c^{2} and 210-240 MeV/c^{2}. This sets upper limits on the branching fractions as B(K_{L}^{0}→XX)<(1-4)×10^{-7} and B(K_{L}^{0}→XX)<(1-2)×10^{-6} at the 90% confidence level for the two mass regions, respectively.