1. KITPC, Jun 14th, 2012 Spin-Isospin excitations as quantitative constraint for the Skyrme tensor force Chunlin Bai Department of Physics, Sichuan University Chengdu, China ● Tensor effects on the excited states ● GT and SD constraint on the tensor force ● Tests of the constraint ● Recent studies in open-shell nuclei ● Skyrme parameter sets with tensor force ● Conclusion and outlook

2. KITPC, Jun 14th, 2012 Skyrme parameter sets with tensor force The tensor terms postulated by Skyrme: Nucl. Phy. 9, 615(1959) Skyrme parameter sets which include tensor force: Fl. Stancu et. al, PLB68, 108(1977), B. A. Brown et. al, PRC74, 061303(2006) T >0, U>0 G. Colò et. al, PLB644, 227(1977), D. M. Brink et. al, PRC74, 061303(2006) T >0, U<0 T. Lesinski et. al. PRC76, 014312(2007) G-Matrix interaction Single-particle energies Ground state properties T ±, U ±

3. KITPC, Jun 14th, 2012 Tensor effects on GT states Bai, Sagawa, Zhang, Zhang, Colò, Xu, Phys. Lett. B675, 28(2009) Main peak Low energy tail

4. KITPC, Jun 14th, 2012 Tensor effects on Charge-exchange SD Exp. From T. Wakasa et. al., PRC 84, 014614(2011) Bai, Zhang, Sagawa, Zhang, Colò, Xu, PRL 105,072501(2010) The SD 1 - state is shifted downward dramatically by the tensor RPA correlations. In T43, T >0, U<0 In SLy5+Tw, T>0, U>0

5. KITPC, Jun 14th, 2012 Tensor effects in M1 excitations Cao, Colò, Sagawa, Bortignon, Sciacchitano, PRC 80, 064304 (2009)

6. KITPC, Jun 14th, 2012 GT and SD constraint on the tensor force Bai, Zhang, Sagawa, Zhang, Colò, Xu, PRC83,054316(2011); The exp.main peak energy of SD and GT in 90 Zr and 208 Pb can be the constraints by requiring the condition ● In TIJ family, only T21, T32, T43, and T54 fulfill the condition; ● SD 1- states strongly constrain the value of T; ● Together with SD, GT main peak can be used to constrain value of U.

7. KITPC, Jun 14th, 2012 Tests of the constraints by SD in 16 O Bai, Sagawa, Colo, Zhang, Zhang, PRC 84, 044329(2011)

8. KITPC, Jun 14th, 2012 Tests of the constraints by IVSM in 90 Zr and 208 Pb K. Miki et. al., PRL 2012

9. KITPC, Jun 14th, 2012 Recent studies in open-shell nuclei HFB+pnQRPA (canonical basis) calculation details: ● In HFB T=1 pairing is adjusted to reproduce the neutron pairing gap of 120 Sn ● In QRPA cut-off neutron states with Choosing of the pairing interaction: HFB pnQRPA The strength of the T=0 pairing is not well evaluated, In N. Vinh Mau, arXiv 0711, 3173 (2007), f=1.36, In our calculation f = 0.0, 0.5, 1, 1.5, 1.7 ● In HFB cut-off of the quasi-particle energy: 180 MeV

10. KITPC, Jun 14th, 2012 GT excitations in Sn isotopes T=0 pairing has almost no effect on the main peak energies.

11. KITPC, Jun 14th, 2012 GT excitations in Sb isotopes

12. KITPC, Jun 14th, 2012 Conclusion and outlook ● Main peak energy of GT and charge-exchange SD transitions in closed shell nuclei can supply good constraint for tensor force; ● In media heavy nuclei such as Sn isotopes, the T=0 pairing force has negligible effects on the main GT peaks; ● GT main peak of media heavy nuclei such as Sn isotopes can also supply good constraint for the tensor force; ● GT excitations in other isotopes and isotonics will be studied; ● Other spin-isospin excitations and the relevant quantities will be studied so as to find constraints for the tensor force.

13. KITPC, Jun 14th, 2012 collaborators G. Colò, INFN, Italy K. Miki, RCNP, Japan H. Sagawa, Aizu univ. Japan F. R. Xu, PKU, China H. Q. Zhang, CIAE, China X. Z. Zhang, CIAE, China

14. KITPC, Jun 14th, 2012