Λ spin-orbit splitting deduced from DWIA analysis of the 89 Y (π +,K + ) Λ 89 Y reaction T. Motoba (Osaka E-C U.) D.J. Millener (Brookhaven N.L.) D. Lanskoy (Moscow State U.) Y. Yamamoto (Tsuru U.)

(π+,K+) reaction characteristics

T.Motoba, H. Bando, R. Wunsch, J.Zofka, Phys. Rev.C38 (1988)

H. Hotchi et al, Phys. Rev. C (2001). Great achievement good resolution Γ=1.65 MeV Ls splitting (ΔE): (f )=1.70 MeV (d)=1.63 (p)= 1.37

High resolution γ-ray mesurements

How to understand “large” splitting of subpeaks observed in heavy systems

ΔE is not proportional to (2l+1)

XS ratio is determined as

EXP vs. DWIA CAL( WS, V LS = 4.3MeV )

Take core-excited states seriously ： up to the level of p-shell hypernuclei

CONCLUSION (1)Reproduce cross section ratios among a series of pronounced peaks and sub-peaks.

CONCLUSION (2) Observed energy spacing between doublet like sub-peaks (3L-3R) are reproduced with δ(f)=0.20 MeV, which leads to δ(d)=0.15 MeV and δ(p)=0.09 MeV. (cf. Λ １３ C:δ(p)= MeV)

CONCLUSION （３） even the GS peak should consists of two components. (See the exp. GS peak The present analysis leads to the prediction that.)

CONCLUSION (4) Right partner(s) contain parity-mixing contributions : example for 3R: [1p 1/2 f 7/2hole ] Λ （ d 3/2 ）

New insight into (π+,K+) spectra for other medium-heavy hypernuclei

END