1	Diabatization: a simple way to get to high-lying excited states A.T. Le and C.D. Lin Dept. of Physics, KSU April 14, 2004
2	Outline Introduction Diabatization procedure: what’s new? Doubly excited states of helium Antihydrogen formation in antiproton colliding with excited positronium
3	Introduction Difficulties with adiabatic basis: Avoided crossings Many channels need to be included Difficult to do calculations with high excited states Diabatic basis has long been proposed. Our goal: Simplified picture with less channels involved Practical calculations.
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15	Table 3: Comparison for 4(3,0)⁺n of He(¹S^e) Resonance positions are given as -E (a.u.). HSCC HSCC HSCC Complex n 1-channel 2-channel 14-channel rotation 4 0.2012 0.2017 0.2017 0.2010 5 0.1651 0.1664 0.1665 0.1657 6 0.1491 0.1514 0.1515 0.1508 7 0.1411 0.1428 0.1429 0.1426 8 0.1366 0.1377 0.1378 0.1377 9 0.1337 0.1345 0.1346 0.1246 10 0.1318 0.1323 0.1324 0.1325 11 0.1304 0.1308 0.1309 0.1310 12 0.1294 0.1298 0.1298 0.1299 13 0.1287 0.1289 0.1290 0.1293 Complex rotation: Burgers et al, JPB 28, 3161 (1995)
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21	Antihydrogen formation Progress in production of cold antihydrogen Charge exchange: Two-stage mechanism Other important mechanisms: Three-body recombination, spontaneous (laser stimulated) radiative recombination.
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26	Note: all the channel are adiabatic with many avoided crossing
27	The channels are diabatic!
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34	Summary Diabatization seems to work well; Less channels, simpler for understanding; “Quantum chaos” signature were found for 3D He; Antihydrogen formation from high-excited Ps can be calculated;