JJAP Conference Proceedings

JJAP Conf. Proc. 7, 011001 (2018) doi:10.7567/JJAPCP.7.011001

Study on positronium Bose–Einstein condensation

Akira Ishida1, Kenji Shu1, Tomoyuki Murayoshi1, Xing Fan1, Toshio Namba1, Shoji Asai1, Kosuke Yoshioka2, Makoto Kuwata-Gonokami1, Nagayasu Oshima3, Brian E. O’Rourke3, Ryoichi Suzuki3

  1. 1Department of Physics, Graduate School of Science, and International Center for Elementary Particle Physics (ICEPP), the University of Tokyo, Bunkyo, Tokyo 113-0033, Japan
  2. 2Photon Science Center (PSC), Graduate School of Engineering, the University of Tokyo, Bunkyo, Tokyo 113-8656, Japan
  3. 3National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan
  • Received September 25, 2017
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Realization of the Bose–Einstein condensation (BEC) of positronium is a long-standing challenge of positron physics. Since the positron is the antimatter of the electron, the positronium is the antimatter of itself, and its gravity interaction is a sum of matter and antimatter components. In this sense, it can be used to study antimatter gravity. It can also be used as a source of a γ-ray laser. We have proposed a new method to realize a positronium BEC: a combination of thermalization in a cold silica target and laser cooling using 1S-2P transitions. We have started some basic studies based on our new idea. Here we report a preliminary result of our positronium thermalization measurement in cryogenic environment and development status of a new laser system for positronium cooling.

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  1. 1 A. Ishida, T. Namba, S. Asai, T. Kobayashi, H. Saito, M. Yoshida, K. Tanaka, and A. Yamamoto, Phys. Lett. B 734, 338 (2014).
  2. 2 A. Miyazaki, T. Yamazaki, T. Suehara, T. Namba, S. Asai, T. Kobayashi, H. Saito, Y. Tatematsu, I. Ogawa, and T. Idehara, Prog. Theor. Exp. Phys. 2015, 011C01 (2015).
  3. 3 Y. Kataoka, S. Asai, and T. Kobayashi, Phys. Lett. B 671, 219 (2009).
  4. 4 A. H. Al-Ramadhan and G. W. Gidley, Phys. Rev. Lett. 72, 1632 (1994).
  5. 5 M. S. Fee, A. P. Mills, Jr., S. Chu, E. D. Shaw, K. Danzmann, R. J. Chichester, and D. M. Zuckerman, Phys. Rev. Lett. 70, 1397 (1993).
  6. 6 T. Yamazaki, T. Namba, S. Asai, and T. Kobayashi, Phys. Rev. Lett. 104, 083401 (2010).
  7. 7 P. A. Vetter and S. J. Freedman, Phys. Rev. Lett. 91, 263401 (2003).
  8. 8 S. G. Karshenboim, Astron. Lett. 35, 663 (2009).
  9. 9 D. B. Cassidy and A. P. Mills, Jr., Phys. Status Solidi C 4, 3419 (2007).
  10. 10 C. B. Stevens, EIR Science & Technology 13 [43], 22 (1986).
  11. 11 H. K. Avetissian, A. K. Avetissian, and G. F. Mkrtchian, Phys. Rev. Lett. 113, 023904 (2014).
  12. 12 H. K. Avetissian, A. K. Avetissian, and G. F. Mkrtchian, Phys. Rev. A 92, 023820 (2015).
  13. 13 K. Shu, X. Fan, T. Yamazaki, T. Namba, S. Asai, K. Yoshioka, and M. Kuwata-Gonokami, J. Phys. B 49, 104001 (2016).
  14. 14 K. Shu, T. Murayoshi, X. Fan, A. Ishida, T. Yamazaki, T. Namba, S. Asai, K. Yoshioka, M. Kuwata-Gonokami, N. Oshima, B. E. O’Rourke, and R. Suzuki, J. Phys.: Conf. Ser. 791, 012007 (2017).
  15. 15 N. Oshima, R. Suzuki, T. Ohdaira, A. Kinomura, T. Narumi, A. Uedono, and M. Fujinami, J. Appl. Phys. 103, 094916 (2008).
  16. 16 Y. Nagashima, M. Kakimoto, T. Hyodo, K. Fujiwara, A. Ichimura, T. Chang, J. Deng, T. Akahane, T. Chiba, K. Suzuki, B. T. A. McKee, and A. T. Stewart, Phys. Rev. A 52, 258 (1995).
  17. 17 T. Chang, M. Xu, and X. Zeng, Phys. Lett. A 126, 189 (1987).
  18. 18 K. Shibuya, Y. Kawamura, and H. Saito, Phys. Rev. A 88, 042517 (2013).
  19. 19 Y. Nagashima, T. Hyodo, K. Fujiwara, and A. Ichimura, J. Phys. B 31, 329 (1998).
  20. 20 S. Agostinelli et al., Nucl. Instrum. Methods Phys. Res., Sect. A 506, 250 (2003).
  21. 21 J. Allison et al., IEEE Trans. Nucl. Sci. 53, 270 (2006).