1. Ground state and resonance states of Ps interacting with screened Coulomb (Yukawa) potentials
Sabyasachi Kar and Y. K. Ho
Institute of Atomic and Molecular Sciences
Academia Sinica, Taipei, Taiwan
[18th International IUPAP Conference
on Few-Body Problems in Physics]
August 21-26, 2006

4. Introduction Bound and resonance states of Ps in dense plasmas
Ps, a simplest three lepton system (e+, e, e)
Experiment : A P Mills, PRL 46 (1981)717; 50 (1983) 671
P Balling et al, NIMB 221 (2004) 200,
D. Schwalm et al, 221(2004) 185
D. B. Cassidy et al, PRL 95 (2005)
Theory : Y K Ho, PRA 48 (1993) 4780; G W F Drake et al, PRA 65 (2002)
054501; A M Frolov Phys. Lett. A 342 (2005) 430.
Ground-state of Ps embedded in Debye plasmas
B Saha et al, CPL 373 (2003) 218
Kar and Ho, PRA 71 (2005)052503, CPL 424 (2006) 403
The 1Se and 1, 3Po resonance states of plasma-embedded Ps
Kar and Ho, PRA 71 (2005) ; PRA 73 (2006)
The Stabilization Method
V A Mandelshtam et al, PRL 70(1993) 1932
Ho and co-workers [J Phys B 38 (2005) and references therein]

11. The Stabilization diagram for the lowest 3Po states of Ps and the fitting of density of states for λD=20. From the fit, we have obtained Er = and = [S. Kar and Y. K. Ho, PRA 73 (2006) ]

12. The 2s2 1Se resonance energies and widths of Ps under Debye screening S. Kar and Y. K. Ho, Phys. Rev. A 71 (2005)

13. The lowest 1,3Po resonance energies of Ps under Debye screening S
The lowest 1,3Po resonance energies of Ps under Debye screening S. Kar and Y. K. Ho, Phys Rev A 73 (2006)

14. The 1,3Po resonance widths of Ps embedded in Debye plasma [Kar and Ho, PRA 73 (2006) 032503]

15. The 2s2 1Se resonance energies of Ps embedded in Debye Plasmas [S
The 2s2 1Se resonance energies of Ps embedded in Debye Plasmas [S. Kar and Y. K. Ho, Phys Rev A 71 (2005) ] λD
Er   a b
4.31[-5]
4.3034[-5]a
4.3[-5]b
100 70
4.29[-5] 50
4.26[-5] 40
4.21[-5] 30
4.09[-5] 20
3.64[-5] 15
2.95[-5] 10
1.16[-5] 9
6.32[-5]
aY K Ho, Chin J Phys 35(1997) 2345, bA. Igarashi et al, J Phys B 37, (2004) 4221.

16. The 1,3Po resonace energies and widths of Ps under Debye Screeing
EPs(2s) 
[-7] * 1.0[-6]*
† [-7] †
[-4]
* [-4]*
[-5]
* 1.6[-5]*
200
[-7]
[-4]
[-5]
100
[-6]
[-4]
[-5] 70
[-6]
[-4]
[-5] 60
[-6]
[-4]
[-5] 50
[-4] 40
[-4] 30
[-4] 25
0.0306
[-4] 20
0.0248
[-5]
0.0249 15
0.0168
[-5]
0.017 10
0.0059
[-5]
*Bhatia and Ho, PRA 42 (1990) †Igarashi et al , NJP 2 (2000) 17

20. Acknowledgements
The work is supported by the National Science Council of Taiwan, R.O.C.
I am thankful to Dr Y. K. Ho for suggesting me the problems, and for his immense help and cooperation to solve the problems.