Kinetic energy distributions of muonic and pionic hydrogen atoms

Abstract

The kinetic energy distributions of μ − p and π − p atoms at a time of the radiative np→1s transitions and charge-exchange reaction (in case of π − p) have been studied in the improved version of extended standard cascade model (ESCM). Ab initio quantum-mechanical calculations of the differential and integral cross sections of the elastic scattering, Stark transitions, Coulomb deexcitation (CD), and induced absorption (in case of pionic hydrogen) have been performed in a framework of the close-coupling approach for the states of exotic atoms with $n\leqslant 8$ and relative motion energies $E \geqslant 0.0001$ eV. The calculated X-ray yields and kinetic energy distributions are in good agreement with the known experimental data. The initial (n, l, E)-distributions of the exotic atoms and target motion are explicitly taken into account.