arXiv subjects

Mariusz Puchalski

Publications and source records attributed to Mariusz Puchalski.

43 records · Page 3Linked to original sources

arXiv2009

Fine and hyperfine splitting of the 2P state in Li and Be$^+$

Accurate calculations of the fine and hyperfine splitting of the 2P state in Li and Be$^+$ isotopes using the explicitly correlated Hylleraas basis set are presented. Theoretical predictions including the mixing of $P_{1/2}$ and $P_{3/2}$ states, relativistic and quantum electrodynamics effects on hyperfine interactions, are compared with experimental values. It is concluded that precise spectroscopic determination of the nuclear magnetic moments requires elimination of nuclear structure effects by combining measurements for two different states.

physics.atom-ph↗

arXiv2008

Relativistic, QED, and finite nuclear mass corrections for low-lying states of Li and Be$^+$

Accurate results for nonrelativistic energy, relativistic, QED, and finite nuclear mass corrections are obtained for $2^1S_{1/2}$, $3^1S_{1/2}$ and $2^1P_{1/2}$ states of the Li atom and Be$^+$ ion. Our computational approach uses the Hylleraas basis set with the analytic integration and recursion relations. From comparison of experimental results for the isotope shifts to theoretical predictions including nuclear polarizabilities, we obtain nuclear charge radii for Li and Be isotopes.

physics.atom-ph↗

arXiv2008

Dipole Excitation of Dipositronium

The energy interval between the ground and the P-wave excited states of the recently discovered positronium molecule Ps_2 is evaluated, including the relativistic and the leading logarithmic radiative corrections, E_P-E_S = 0.181 586 7(8) a.u. The P-state, decaying usually via annihilation, is found to decay into the ground state by an electric dipole transition 19 percent of the time. Anticipated observation of this transition will provide insight into this exotic system.

hep-ph↗

arXiv2008

Singular Hylleraas three-electron integrals

Calculations of the leading quantum electrodynamics effects in few electron systems involve singular matrix elements of the inter-electronic distances of the form $1/r_i^3$ and $1/r_{ij}^3$. Integrals that result when the nonrelativistic wave function is represented with a Hylleraas basis representation are studied. Recursion relations for various powers of the electron coordinates and the master integrals are derived in a form suited for high precision numerical evaluations.

physics.atom-ph↗

arXiv2007

Positronium-ion decay

We present a precise theoretical prediction for the decay width of the bound state of two electrons and a positron (a negative positronium ion), Gamma(Ps^-) = 2.087 085(12)/ns. We include O(alpha^2) effects of hard virtual photons as well as soft corrections to the wave function and the decay amplitude. An outcome of a large-scale variational calculation, this is the first result for second-order corrections to a decay of a three-particle bound state. It will be tested experimentally in the new positronium-ion facility in Garching in Germany.

hep-ph↗

arXiv2006

Ground state wave function and energy of the lithium atom

Highly accurate nonrelativistic ground-state wave function and energy of the lithium atom is obtained in the Hylleraas basis set. The leading relativistic corrections,as represented by Breit-Pauli Hamiltonian, are obtained in fair agreement with the former results. The calculational method is based on the analytical evaluation of Hylleraas integrals with the help of recursion relations.

physics.atom-ph↗

arXiv2004

Recursion relations for Hylleraas three-electron integral

Recursion relations for Hylleraas three-electron integral are obtained in a closed form by using integration by parts identities. Numerically fast and well stable algorithm for the calculation of the integral with high powers of inter-electronic coordinates is presented.

physics.atom-ph↗