학술논문
Search for the $\eta$ mesic $^3$He in the $pd\rightarrow d p \pi^{0}$ reaction with the WASA-at-COSY facility
Document Type
Working Paper
Author
Adlarson, P.; Augustyniak, W.; Bashkanov, M.; Bass, S. D.; Bergmann, F. S.; Berlowski, M.; Bondar, A.; Buscher, M.; Calen, H.; Ciepal, I.; Clement, H.; Czerwinski, E.; Demmich, K.; Engels, R.; Erven, A.; Erven, W.; Eyrich, W.; Fedorets, P.; Fohl, K.; Fransson, K.; Goldenbaum, F.; Goswami, A.; Grigoryev, K.; Heijkenskjold, L.; Hejny, V.; Husken, N.; Hirenzaki, S.; Johansson, T.; Kamys, B.; Kelkar, N. G.; Kemmerling, G.; Khoukaz, A.; Khreptak, A.; Kirillov, D. A.; Kistryn, S.; Kleines, H.; Klos, B.; Krzemien, W.; Kulessa, P.; Kupsc, A.; Lalwani, K.; Lersch, D.; Lorentz, B.; Magiera, A.; Maier, R.; Marciniewski, P.; Marianski, B.; Morsch, H. -P.; Moskal, P.; Ohm, H.; Parol, W.; del Rio, E. Perez; Piskunov, N. M.; Prasuhn, D.; Pszczel, D.; Pysz, K.; Ritman, J.; Roy, A.; Rundel, O.; Sawant, S.; Schadmand, S.; Sefzick, T.; Serdyuk, V.; Shwartz, B.; Skorodko, T.; Skurzok, M.; Smyrski, J.; Sopov, V.; Stassen, R.; Stepaniak, J.; Stephan, E.; Sterzenbach, G.; Stockhorst, H.; Stroher, H.; Szczurek, A.; Wolke, M.; Wronska, A.; Wustner, P.; Yamamoto, A.; Zabierowski, J.; Zielinski, M. J.; Zlomanczuk, J.; Zurek, M.
Source
Phys. Rev. C 102, 044322 (2020)
Subject
Language
Abstract
The excitation function for the $pd\rightarrow$ $d p \pi^{0}$ reaction has been measured by WASA-at-COSY experiment with the aim of searching for $^{3}\hspace{-0.03cm}\mbox{He}$-$\eta$ mesic nuclei. The measurement in the vicinity of $\eta$ meson production was performed using a ramped proton beam. The data analysis and interpretation was carried out with the assumption that the $\eta$-mesic Helium decays via the formation of an intermediate N$^{*}$(1535) resonance. No direct signal of the $\eta$-mesic nucleus is observed in the excitation function. We determine a new improved upper limit for the total cross section for the bound state production and decay in the $pd\rightarrow$ $(^{3}\hspace{-0.03cm}\mbox{He}$-$\eta)_{bound} \rightarrow$ $d p \pi^{0}$ process. It varies between 13 nb to 24 nb for the bound state with width in the range $\Gamma \in (5,50)$ MeV.