Experimental study of Λn interaction via FSI effect in the γ+d reaction at ELPH, Spring-8, and JLab.

The Λn interaction is the last key of the study of Baryon-Baryon interaction. Since the Σp/Λp interaction study is developed with the modern technique in J-PARC, we need to make the Λn interaction clear to solve the problem of the charge symmetry braking in the Lambda-Nucleon (ΛN) interaction. It is difficult to make Lambda and neutron be a target and a beam so that the Final-State-Interaction (FSI).

We proposed and are preparing an experiment of Λn interaction measurement via FSI in the γ+d→K⁺+Λ+n reaction by using NKS2 spectrometer at ELPH, Tohoku University. As further experiments, we have plans to investigate ΣN-ΛN coupling effect by polarization observables as a function of K⁺ angle/momentum [1] and a cusp in the differential cross section of K⁺ as a function of momentum [2] in γ+d→K⁺+X reaction. The first one will be proposed as an experiment at LEPS2, Spring-8 and we are planning the second one using HES and HKS spectrometers at Hall C, JLab. I will introduce those experimental plans and show the feasibility of the measurement in this talk.



[1] K. Miyagawa, T. Mart, C. Bennhold, and W. Glöckle, Phys. Rev. C74 (034002 (2006)

[2] H. Yamamura, K. Miyagawa, T. Mart, C. Bennhold, H. Habrezetil, and W. Glöckle, Phys. Rev. C61. 014001 (1999)