Positron annihilation in the MuPs system

TL;DR

This paper calculates the positron annihilation rates, lifetime, and hyperfine splitting for the MuPs system, providing precise numerical results for these properties of this four-body atomic system.

Contribution

It presents detailed calculations of annihilation rates, lifetime, and hyperfine splitting for the MuPs system, a novel four-body atomic system involving muonium and positronium.

Findings

Positron annihilation lifetime is approximately 4.08 x 10^{-10} seconds.

Annihilation rates for 2, 3, 4, and 5 gamma processes are numerically determined.

Hyperfine structure splitting is evaluated as 23.078 MHz.

Abstract

The life-time of the four-body atomic system MuPs ($\mu^{+} e^{-}_2 e^{+}$ or muonium-positronium) against positron annihilation has been evaluated as $\tau = \frac{1}{\Gamma} \approx 4.076453 \cdot 10^{-10}$ $sec$. Various annihilation rates for MuPs are determined to a good numerical accuracy, e.g., $\Gamma_{2 \gamma} \approx$ 2.446485$\cdot 10^{9}$ $sec^{-1}$, $\Gamma_{3 \gamma} \approx$ 6.62798$\cdot 10^{6}$ $sec^{-1}$, $\Gamma_{4 \gamma} \approx$ 3.61680$\cdot 10^{3}$ $sec^{-1}$, $\Gamma_{5 \gamma} \approx$ 6.32973 $sec^{-1}$. The hyperfine structure splitting for the ground state in the MuPs system has also been evaluated as $\Delta$ = 23.078 $MHz$.