A new order $α$ correction to the decay rate of pionium
| dc.creator | Labelle, P. | |
| dc.creator | Buckley, K. | |
| dc.date | 1998-04-01 | |
| dc.date.accessioned | 2026-07-07T04:03:40Z | |
| dc.date.available | 2026-07-07T04:03:40Z | |
| dc.description | Recently, much work has been devoted to the calculation of order $α$ corrections to the decay rate of pionium, the $π^+ π^-$ bound state. In previous calculations, nonrelativistic QED corrections were neglected since they start at order $α^2$ in hydrogen and positronium. In this note, we point out that there is one correction which is actually of order $α$ times a function of the ratio $μ_r α/ m_e$, where $μ_r$ is the reduced mass of the system. When $μ_r α\ll m_e$, this function can be Taylor expanded and leads to higher order corrections. When $μ_r α\approx m_e$, as is the case in pionium, the function is of order one and the correction is of order $α$. We use an effective field theory approach to calculate this correction and find it equal to $0.4298 αΓ_0$. We also calculate the corresponding correction to the dimuonium ($μ^+ μ^-$ bound state) decay rate and obtained a result in agreement with Jentschura et al. | |
| dc.description | 7 pages, 5 Postscript figures, uses Revtex V3.0 and epsf.tex | |
| dc.identifier | https://arxiv.org/abs/hep-ph/9804201 | |
| dc.identifier | http://arxiv.org/abs/hep-ph/9804201 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/47760 | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.title | A new order $α$ correction to the decay rate of pionium | |
| dc.type | text |