Precise Calculation Of Structure And External-Field-Effect Of Hydrogen Molecular Ions And Antiproton Helium

The molecular hydrogen ions(MHI), containing two nuclei and an electron, are the sim-plest stable molecules. The antiprotonic helium pHe+ is formed by stopping antiprotons in a helium medium, and the antiproton occupies a large angular momentum Rydberg state. The molecular hydrogen ions and antiprotonic helium are theoretically amenable to high-accuracy ab initio calculation including relativistic and QED effects. On the experimental side, their spectroscopies can be determined to a high precision. The their precision spec-troscopies can not only test the bound state QED theory and CPT theory at high precision, but also determine (anti)proton to electron mass ratio. The precision of experimental spec-troscopy beyond ppb level are confronted with many technical problems, systematic error and new experiments to be operated, requiring the theoretical calculation about structure and external field effects such as transition probability, polarizability and long range interactions. The theoretical calculation is essential for related spectroscopy experiments, designing new experiment scheme and analysing systematic errors and also providing benchmark for sub-sequent theoretical study, which is an important part of precision spectroscopies of hydrogen molecular ions and antiproton helium.(1)For the hydrogen molecular ions HD+, HT+, and DT+, we have used variation-al method in Hylleraas basis sets to calculate all the ro-vibrational energies and oscillator strengths of dipole transition between two ro-vibrational states with v=0-5 and L=0-5.(2)It is important to evaluate external field effects such as Ac/Dc Stark shift and the blackbody radiation (BBR) shift which are related with polarizability. All the polarizability of HD+rovibrational states (v= 0-5,L= 0-5) are calculated with variational method. And from the dynamic polarizability, we determined tune-out wavelenth and magic wave-length for some experiment interested rotational transition.(3)Precision spectroscopy of antiproton helium beyond 1 ppb level is limited by the density shift and broadening, so the long range interaction between antiprotonic helium and helium atoms is important for evaluation of collisional effects on the experimentally ob-served spectral lines. We variationally solved the eigen problem of helium and Rydberg state antiproton helium (n～L= 30-40) in correlated Hylleraas coordinates. The polar-izability is calculated which is potentially applied for future precision spectroscopy of the antiprotonic helium. The leading term of long-range interaction between ground state heli-um and high excited pHe+ is systematically studied, which can be used for estimating the collisional shift and broadening of the transition frequencies of antiprotonic helium at low temperature.