학술논문
Inclusive spectrum of the $d(\pi^+, K^+)$ reaction at 1.69 GeV/c
Document Type
Working Paper
Author
Ichikawa, Yudai; Nagae, Tomofumi; Bhang, Hyoungchan; Bufalino, Stefania; Ekawa, Hiroyuki; Evtoukhovitch, Petr; Feliciello, Alessandro; Fujioka, Hiroyuki; Hasegawa, Shoichi; Hayakawa, Shuhei; Honda, Ryotaro; Hosomi, Kenji; Imai, Ken'ichi; Ishimoto, Shigeru; Joo, Changwoo; Kanatsuki, Shunsuke; Kiuchi, Ryuta; Koike, Takeshi; Kumawat, Harphool; Matsumoto, Yuki; Miwa, Koji; Moritsu, Manabu; Naruki, Megumi; Niiyama, Masayuki; Nozawa, Yuki; Ota, Ryosuke; Sakaguchi, Atsushi; Sako, Hiroyuki; Samoilov, Valentin; Sato, Susumu; Shirotori, Kotaro; Sugimura, Hitoshi; Suzuki, Shoji; Takahashi, Toshiyuki; Takahashi, Tomonori N.; Tamura, Hirokazu; Tanaka, Toshiyuki; Tanida, Kiyoshi; Tokiyasu, Atsushi O.; Tsamalaidze, Zviadi; Roy, Bidyut; Ukai, Mifuyu; Yamamoto, Takeshi O.; Yang, Seongbae
Source
Subject
Language
Abstract
We have measured an inclusive missing-mass spectrum of the $d(\pi^+, K^+)$ reaction at the pion incident momentum of 1.69 GeV/$c$ at the laboratory scattering angles between 2$^\circ$ and 16$^\circ$ with the missing-mass resolution of 2.7 $\pm$ 0.1 MeV/$c^2$ (FWHM) at the missing mass of 2.27 GeV/$c^{2}$. In this Letter, we first try to understand the spectrum as a simple quasi-free picture based on several known elementary cross sections, considering the neutron/proton Fermi motion in deuteron. While gross spectrum structures are well understood in this picture, we have observed two distinct deviations; one peculiar enhancement at 2.13 GeV/$c^2$ is due to the $\Sigma N$ cusp, and the other notable feature is a shift of a broad bump structure, mainly originating from hyperon resonance productions of $\Lambda(1405)$ and $\Sigma(1385)^{+/0}$, by about 22.4 $\pm$ 0.4 (stat.) $^{+2.7}_{-1.7}$ (syst.) MeV/$c^2$ toward the low-mass side, which is calculated in the kinematics of a proton at rest as the target.
Comment: 8 pages, 3 figures, submitted to PTEP
Comment: 8 pages, 3 figures, submitted to PTEP