WNPPC2023 - 60th Winter Nuclear Particle Physics Conference

Decay Rates of Positronium Species

18 Feb 2023, 10:00

15m

KC 303 (Banff Centre)

Contributed Oral Particle Physics February 18 Morning Session

Speaker

Muhammad Mubasher (University of Alberta)

Description

It has been known for many years that an electron and its antiparticle, the positron, may together form a metastable hydrogen-like atom, known as positronium or Ps. In 1946, Wheeler speculated that two Ps atoms may combine to form the positronium molecule (Ps${}_2$) stable with respect to auto-dissociation. In 2007, the existence of Ps${}_2$ was confirmed experimentally by David Cassidy and? Allen Mills at the University of California.

I will present a determination of the radiation-less and two photon decay rates of Ps${}_2$. We employ a simple technique to compute the amplitudes and write the products of spinors in terms of gamma matrices, which reduces the computational time and provides more insights into the physics of a reaction. After testing the method with the well known problem of para-positronium (p-Ps) and positronium ion (Ps${}^{-1}$), I will present decay rate calculation of Ps${}_2\to e^{-}{e}^{+}$ and Ps${}_2\to \gamma \gamma$, and demonstrate that the previously published results are incorrect.

Presentation materials

Decay_rates_of_Ps_Species.pdf