학술논문
High-resolution search for the $\Theta^{+}$ pentaquark via a pion-induced reaction at J-PARC
Document Type
Working Paper
Author
Collaboration, J-PARC E19; Moritsu, M.; Adachi, S.; Agnello, M.; Ajimura, S.; Aoki, K.; Bhang, H. C.; Bassalleck, B.; Botta, E.; Bufalino, S.; Chiga, N.; Ekawa, H.; Evtoukhovitch, P.; Feliciello, A.; Fujioka, H.; Hayakawa, S.; Hiruma, F.; Honda, R.; Hosomi, K.; Ichikawa, Y.; Ieiri, M.; Igarashi, Y.; Imai, K.; Ishibashi, N.; Ishimoto, S.; Itahashi, K.; Iwasaki, R.; Joo, C. W.; Kanatsuki, S.; Kim, M. J.; Kim, S. J.; Kiuchi, R.; Koike, T.; Komatsu, Y.; Kulikov, V. V.; Marcello, S.; Masumoto, S.; Matsumoto, Y.; Matsuoka, K.; Miwa, K.; Nagae, T.; Naruki, M.; Niiyama, M.; Noumi, H.; Nozawa, Y.; Ota, R.; Ozawa, K.; Saito, N.; Sakaguchi, A.; Sako, H.; Samoilov, V.; Sato, M.; Sato, S.; Sato, Y.; Sawada, S.; Sekimoto, M.; Shirotori, K.; Sugimura, H.; Suzuki, S.; Takahashi, H.; Takahashi, T.; Takahashi, T. N.; Tamura, H.; Tanaka, T.; Tanida, K.; Tokiyasu, A. O.; Tomida, N.; Tsamalaidze, Z.; Ukai, M.; Yagi, K.; Yamamoto, T. O.; Yang, S. B.; Yonemoto, Y.; Yoon, C. J.; Yoshida, K.
Source
Phys. Rev. C 90, 035205 (2014)
Subject
Language
Abstract
The pentaquark $\Theta^+$ has been searched for via the $\pi^-p \to K^-X$ reaction with beam momenta of 1.92 and 2.01 GeV/$c$ at J-PARC. A missing mass resolution of 2 MeV (FWHM) was achieved but no sharp peak structure was observed. The upper limits on the production cross section averaged over the scattering angle from 2$^{\circ}$ to 15$^{\circ}$ in the laboratory frame were found to be less than 0.28 $\mu$b/sr at the 90\% confidence level for both the 1.92- and 2.01-GeV/$c$ data. The systematic uncertainty of the upper limits was controlled within 10\%. Constraints on the $\Theta^+$ decay width were also evaluated with a theoretical calculation using effective Lagrangian. The present result implies that the width should be less than 0.36 and 1.9 MeV for the spin-parity of $1/2^+$ and $1/2^-$, respectively.
Comment: 12 pages, 9 figures; published version
Comment: 12 pages, 9 figures; published version