spin-isospin excitations as quantitative constraint for the skyrme tensor force
DESCRIPTION
Spin-Isospin excitations as quantitative constraint for the Skyrme tensor force. Chunlin Bai. Department of Physics, Sichuan University Chengdu, China. ● Skyrme parameter sets with tensor force. ● Tensor effects on the excited states. ● GT and SD constraint on the tensor force. - PowerPoint PPT PresentationTRANSCRIPT
KITPC, Jun 14th, 2012
Spin-Isospin excitations as quantitative constraint for the Skyrme tensor force
Chunlin BaiDepartment 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
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-Matrixinteraction
Single-particleenergies
Ground stateproperties
T ±,U ±
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
KITPC, Jun 14th, 2012
Tensor effects on Charge-exchange SD
Exp. FromT. 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<0In SLy5+Tw, T>0, U>0
KITPC, Jun 14th, 2012
Tensor effects in M1 excitations
Cao, Colò, Sagawa, Bortignon, Sciacchitano, PRC 80, 064304 (2009)
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 90Zr and 208Pb 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.
exp2.5
thE E MeV
KITPC, Jun 14th, 2012
Tests of the constraints by SD in 16O
Bai, Sagawa, Colo, Zhang, Zhang,PRC 84, 044329(2011)
KITPC, Jun 14th, 2012
Tests of the constraints by IVSM in 90Zr and 208Pb
K. Miki et. al., PRL 2012
KITPC, Jun 14th, 2012
Recent studies in open-shell nucleiHFB+pnQRPA (canonical basis) calculation details:
● In HFB T=1 pairing is adjusted to reproduce the neutron pairing gap of 120Sn
● In QRPA cut-off neutron states with 2 610nv
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
KITPC, Jun 14th, 2012
GT excitations in Sn isotopes
T=0 pairing has almost no effect on the main peak energies.
0 5 10 15 20 25 300
2
4
6
8
10
12
14
0 5 10 15 20 25 300 5 10 15 20 25 30
0 5 10 15 20 25 300
8
16
0 5 10 15 20 25 300 5 10 15 20 25 30
GT
str
engt
h (M
eV-1)
112Sn
114Sn
f=0.0 f=0.5 f=1.0 f=1.5 f=1.7
116Sn
GT
str
engt
h (M
eV-1)
Ex (MeV)
118Sn
Ex (MeV)
120Sn
Ex (MeV)
124Sn
KITPC, Jun 14th, 2012
112 114 116 118 120 122 1246
8
10
12
14
16
18
EG
T M
eV
A
exp T21 T32 T43 T54 Te1 Te2
GT peak energy in Sb isotopes
E
th-E
exp
< 1.5 MeV
GT excitations in Sb isotopes
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.
KITPC, Jun 14th, 2012
collaboratorsG. 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
KITPC, Jun 14th, 2012