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Tensor Optimized Few-body Model for s-shell nuclei. 23.8.2011. APFB11. Kaori Horii , Hiroshi Toki (RCNP, Osaka univ.) Takayuki Myo, (Osaka Institute of Technology) Kiyomi Ikeda (RIKEN Nishina Center). Introduction.
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Tensor Optimized Few-body Model for s-shell nuclei 23.8.2011 APFB11 Kaori Horii, Hiroshi Toki (RCNP, Osaka univ.) Takayuki Myo, (Osaka Institute of Technology) Kiyomi Ikeda (RIKEN Nishina Center)
Introduction Realistic NN interaction ⇒ strong short range repulsion and tensor interaction ★Deuteron result with AV8’ potential *D-wave component is small, the probability is 5% *The dominant attraction of 80% is caused by the tensor interaction. ★Method for treating the strong tensor int. Tensor Optimized Shell Model (TOSM) Myo, Toki, Ikeda We expect to develop medium and heavy nuclei using realistic NN int.
Motivation TOSM +UCOM (only S-wave relative motion) 4He calculation with NN int (AV8’). T.Myo et al (2009) H.Kamada et al (2001) *Where is the difference between TOSM and the rigorous calculation? *What should be done to improve the description of nuclei ? Few-body technique (relative coordinates) by introducing the spirit of TOSM approximation. → Tensor Optimized Few-body Model (TOFM)
Tensor Optimized Few-body Model (TOFM) TOFM (Few-body) TOSM (Shell-Model) ******* *D-wave state contains a single Y2 function in the relative coordinates. ( No double and triple Y2 , No Y1 functions) *The most essential Y2 function is in the relative coordinate x1 *small variational model space
Tensor Optimized Few-body Model (TOFM) TOFM (Few-body) TOSM (Shell-Model) ******* *D-wave state contains a single Y2 function in the relative coordinates. ( No double and triple Y2 , No Y1 functions) *The most essential Y2 function is in the relative coordinate x1 *small variational model space Deuteron like state (S=1,T=0) TOFM wave function describes the deuteron like state in nuclei.
Tensor Optimized Few-body Model (TOFM) Jacobi coordinate x1,x2,x3 For 4He Total J=0, S-wave(L=0,S=0), D-wave(L=2,S=2) *Correlated gaussian basis with the global vector Few Body System 42(2008 )33-72 Y.Suzuki, et al global vector TOFMapprox. *Variational calculation on the basis of the Stochastic Variational Method (SVM) Gaussian range matrix A are given as random parameters
★Numerical resultfor 3H with AV8’ potential Few Body System 42(2008 )33-72 Y.Suzuki, et al Kinetic Energy [MeV] LS Energy Central Tensor TOFM results compare almost perfectly with the rigorous few-body calculation.
★Numerical resultfor 4He with AV8’ potential (w/o Coul.) Few Body System 42(2008 )33-72 Y.Suzuki, et al Kinetic Energy [MeV] LS Energy Central Tensor The missing strength come from the kinetic and tensor matrix elements. The inclusion of double Y2 functions brings the total energy very close.
★4He~ Comparison with Tensor Optimized Shell Model (TOSM) ~ TOFM (Few-body) TOSM (Shell-Model) T. Myo et al, PTP121,No3(2009)511, *The energy values are better than the TOSM result. *The large differences come from the kinetic and tensor components. *TOSM calculation can be improvedby taking more suitable UCOM correlation function in the short range correlation.
Correlation function with TOFM w.f. H.Kamada et al (2001) PRC64, 044001 S-wave and D-wave Correlation functions for 2H,3H, and 4He *The dip structure below 1 fm reflects the presence of the strong short range repulsion. *The magnitude of the peak reflects the size of nuclei. *d-wave components are found significant and similar among the three nuclei. S 4He (1.52 fm) 3H (1.78 fm) 2H (1.95 fm) D
4He (1.52 fm) 3H (1.78 fm) 2H (1.95 fm) Correlation function with TOFM w.f. H.Kamada et al (2001) PRC64, 044001 S-wave and D-wave Correlation functions for 2H,3H, and 4He we normalize the correlation functions to those of 4He. *The same short range behavior below 1 fm for both S and D *The size of nuclei determine the correlation function at large distance. *This is an important finding for the study of heavier nuclei. S D
AV8’ (with tensor) MT-V (w/o tensor) Correlation function for S-wave To improve the TOSM (shell-model) results ⇒ the short range correlation is treated by the UCOM ⇒ UCOM function form is obtained with the central MT-V[1] int. Difference of S-wave Correlation function for 4He between AV8’ and MT-V *The short range behavior of the correlation function depends on the properties of interaction. *It is interesting to modify the correlation function in the UCOM. S [1]R.A.Malfliet and j.A..Tjon, NPA127, 61(1969)
Summary & Outlook * We have formulated a tensor-optimized few-body model (TOFM) in the spirit of the TOSM * TOFM app. has a small variational model space (single Y2 in D-wave) * The good reproduction of the rigorous results indicates that nuclei like to have deuteron configuration. * The short range behaviors of correlation function are very similar for the s-shell nuclei. *The correlation function in UCOM should be studied further in the TOSM flamework. * The present study is very encouraging to extend our study for nuclei with A>5 in TOFM flamework. EX) 5He structure, 4He+n Phase Shift, 8Be(4He+4He RGM)…