Inclusive spectrum of the $d({\pi }^{+},K^{+})$ reaction at 1.69 GeV/c

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.) ${}_{-1.7}^{+2.7}$ (syst.) MeV/$c^2$ toward the low-mass side, which is calculated in the kinematics of a proton at rest as the target.

8 pages, 3 figures, submitted to PTEP

References in corpus (1)

• The basic K nuclear cluster K- pp and its enhanced formation in the p + p -> K+ + X reaction

Cited by in corpus (4)

• Observation of the "$K^{-}pp$"-like structure in the $d({\pi }^{+},K^{+})$ reaction at 1.69 GeV/$c$
• Application of a coupled-channel Complex Scaling Method with Feshbach projection to the $K^{-}pp$ system
• Double-pole nature of $\Lambda (1405)$ studied with coupled-channel complex scaling method using complex-range Gaussian basis
• MESON2016 -- Concluding Remarks