Λ spin-orbit splitting deduced from DWIA analysis of

the 89Y(π+,K+) Λ89Y 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. C64044302 (2001).

Great achievementgood 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, VLS=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 li

ke sub-peaks (3L-3R) are reproduced wit

h δ(f)=0.20 MeV, which leads to δ(d)=0.15 M

eV and δ(p)=0.09 MeV.

(cf. Λ １３ C:δ(p)=0.152+-0.07 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: [1p1/2f7/2hole] Λ （ d3/2 ）

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

END