Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical Review A

Detection of Positronium Hydride

David M. Schrader, Teri Petersen

Published Jan 1, 1971• 7 citations
Publisher

Abstract

Annihilation converts positronium hydride into photons and a hydrogen atom. We calculate the probability that the residual hydrogen atom will relax to each of number of bound states. The results suggest an experiment for detecting positronium hydride in a system in which excited hydrogen atoms do not exist except as the residue after annihilation. The experiment consists of measuring the intensity increase of the Lyman -$\ensuremath{\alpha}$ line upon quenching the $2s$ atoms to $2p$ atoms. We predict that the intensity will increase by a factor of 35.

DOI
10.1103/physreva.3.61

Related papers

Signature of the existence of the positronium molecule

J. Usukura, Kálmán Varga, Y. Suzuki

The positronium molecule $({\mathrm{Ps}}_{2})$ has not been experimentally observed yet because its tiny (4.5 eV) binding energy cannot be detected when the molecule annihilates by emitting two photons with energy of 0.51 MeV each. It is shown in this paper that the electric dipole transition between the recently found $L=1$ excited state and the $L=0$ ground state with its characteristic photon energy of 4.94 eV is a clear signature of the existence of the positronium molecule and the possibility of its experimental observation is realistic. The probability of this transition is about 17% of the total decay rate. Another Coulomb four-body system containing positron HPs (the positronium hydride or hydrogen positride), is also included for comparison.

arXiv:physics/9804023•Physical Review A•Sep 1, 1998•106 citations

Positronium-hydrogen elastic scattering

Richard J. Drachman, S. K. Houston

We have investigated the elastic scattering of positronium atoms by hydrogen atoms below the excitation threshold at 5.1 eV, limiting the investigation to the spin-zero (singlet) state of the two electrons. Nonresonant $S$-wave phase shifts have been obtained from normalizable trial functions by extracting the center-of-mass wave function and examining its spatial behavior. An effective-range expansion is fitted to the phase shifts and the previously obtained positronium-hydride bound-state energy to yield a scattering length $a\ensuremath{\cong}5.3{a}_{0}$ compared with Fraser's corrected exchange result, $a=7.28{a}_{0}$ (${a}_{0}$ is the Bohr radius). The stabilization method suggests that a resonance occurs at a scattering energy of 4.5 eV, about 0.6 eV below the excitation threshold. Using the complex rotation method, we have obtained evidence confirming the existence of the resonance and an estimate of its width of about 6 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}2}$ eV.

Physical Review A•Sep 1, 1975•91 citations

Autodissociating Rydberg states of positronium hydride

Richard J. Drachman

The "molecule" positronium hydride (PsH), consisting of one atom each of positronium and hydrogen, has one well-known particle-stable state of total energy $E=\ensuremath{-}1.575$ Ry. In addition, for each $L$ it must have an infinite Rydberg series of excited states whose principal configuration is (${e}^{+}{\mathrm{H}}^{\ensuremath{-}}$), converging to a limit at $E=\ensuremath{-}1.0555$ Ry, the energy of ${\mathrm{H}}^{\ensuremath{-}}$. All of these excited states are energetically able to dissociate into ground-state Ps + H, and the higher-lying states can also decay with emission of excited Ps and ground-state H. These Rydberg states should appear as resonances in Ps + H scattering. In this paper I compute the lowest $S$-wave resonance parameters, using an optical-potential formalism based on the (${e}^{+}{\mathrm{H}}^{\ensuremath{-}}$) configuration. The results are in rough agreement with those previously obtained using Kohn variational or complex-rotation techniques with highly correlated trial functions. The physical description of the PsH excited states is thus clarified.

Physical Review A•May 1, 1979•52 citations

Spontaneous-stimulated annihilation of positronium atoms in the field of intrinsic and external annihilation photons

O. N. Gadomskiĭ, Yu. Yu. Voronov

The Heisenberg equations of motion for the atomic and photonic operators are used, without recourse to perturbation theory, to calculate the lifetime, energy shift, phase relaxation time and oscillation frequency of a positronium atom under the conditions of two-photon annihilation decay in a field of 'seed' photons.

Quantum Electronics•Sep 30, 1996•0 citations

Contribution of various spin configurations to the radiationless decay of PsH

Iraj Masood, S. Zayad Munir, M. Jamil Aslam

Positronium hydride $(\text{PsH})$ is a weakly bound (molecular) state of two electrons $({e}^{\ensuremath{-}})$, a positron $({e}^{+})$, and a proton $({p}^{+})$. Due to the ${e}^{\ensuremath{-}}\ensuremath{-}{e}^{+}$ annihilation, it decays to a number of processes, where the radiationless decay is one of the most important channels. In this decay process, the photons released from the ${e}^{\ensuremath{-}}\ensuremath{-}{e}^{+}$ annihilation are absorbed by the remaining ${e}^{\ensuremath{-}}$ and ${p}^{+}$ in PsH, giving us $\text{PsH}\ensuremath{\rightarrow}{e}^{\ensuremath{-}}{p}^{+}$. For a particular spin (singlet) configuration of the constituents of PsH, the radiationless decay rate of PsH was determined by Aslam et al. [Phys. Rev. A 104, 052803 (2021)]. In this work, we calculate the decay rate of $\text{PsH}\ensuremath{\rightarrow}{e}^{\ensuremath{-}}{p}^{+}$ by exercising all possible spin orientations of PsH and the final states ${e}^{\ensuremath{-}}$ and ${p}^{+}$. By summing all the contributions, we verify that the result is the same if we calculate it using the standard fermion spin-sum technique of quantum field theory.

Physical Review A•Mar 25, 2024•1 citation

Doubly excited autodissociating resonant states of positronium hydride

Yi Zhang, M.-S. Wu, Guo-An Yan +3 more

A doubly excited autodissociating resonant state in positronium hydride has been discovered, which is situated in a Rydberg series converging to the ${\mathrm{H}}^{\ensuremath{-}}(2{s}^{2})+{e}^{+}$ threshold. Previous research has noted a scarcity of such highly excited resonant states, particularly those with a doubly excited nature. The exploration of these states was made possible by employing a projection operator method supported by the stochastic variational method. Accurate calculations of the resonant positions and widths were performed using the complex coordinate rotation method with explicitly correlated Gaussians as basis functions. Our analysis has revealed the intrinsic structural characteristics of these highly excited states. The probability density distribution demonstrates that most resonant states of positronium hydride tend to favor either a ${\mathrm{H}}^{\ensuremath{-}}+{e}^{+}$ or ${\mathrm{Ps}}^{\ensuremath{-}}+{\mathrm{H}}^{+}$ configuration. However, two doubly excited resonant states exhibit a unique characteristic involving both the ${\mathrm{H}}^{\ensuremath{-}}+{e}^{+}$ and ${\mathrm{Ps}}^{\ensuremath{-}}+{\mathrm{H}}^{+}$ configurations. By integrating the probability density distribution with a quantum defect formula, highly excited resonances can be accurately assigned to either the ${\mathrm{H}}^{\ensuremath{-}}(2{s}^{2})+{e}^{+}$ or ${\mathrm{Ps}}^{\ensuremath{-}}(1{s}^{2})+{\mathrm{H}}^{+}$ Rydberg series, thereby reducing discrepancies compared to earlier classifications.

Physical Review A•Nov 16, 2023•2 citations
Annihilation converts positronium hydride into photons and a hydrogen atom. We calculate the probability that the residual hydrogen atom will relax to each of number of bound states. The results suggest an experiment for detecting positronium hydride in a system in which excited hydrogen atoms do not exist except as the residue after annihilation. The experiment consists of measuring the intensity increase of the Lyman -\ensuremathα\ensuremath{\alpha}\ensuremathα line upon quenching the 2s2s2s atoms to 2p2p2p atoms. We predict that the intensity will increase by a factor of 35.
The positronium molecule (Ps2)({\mathrm{Ps}}_{2})(Ps2​) has not been experimentally observed yet because its tiny (4.5 eV) binding energy cannot be detected when the molecule annihilates by emitting two photons with energy of 0.51 MeV each. It is shown in this paper that the electric dipole transition between the recently found L=1L=1L=1 excited state and the L=0L=0L=0 ground state with its characteristic photon energy of 4.94 eV is a clear signature of the existence of the positronium molecule and the possibility of its experimental observation is realistic. The probability of this transition is about 17% of the total decay rate. Another Coulomb four-body system containing positron HPs (the positronium hydride or hydrogen positride), is also included for comparison.
We have investigated the elastic scattering of positronium atoms by hydrogen atoms below the excitation threshold at 5.1 eV, limiting the investigation to the spin-zero (singlet) state of the two electrons. Nonresonant SSS-wave phase shifts have been obtained from normalizable trial functions by extracting the center-of-mass wave function and examining its spatial behavior. An effective-range expansion is fitted to the phase shifts and the previously obtained positronium-hydride bound-state energy to yield a scattering length $a\ensuremath{\cong}5.3{a}_{0}$ compared with Fraser's corrected exchange result, a=7.28a0a=7.28{a}_{0}a=7.28a0​ (a0{a}_{0}a0​ is the Bohr radius). The stabilization method suggests that a resonance occurs at a scattering energy of 4.5 eV, about 0.6 eV below the excitation threshold. Using the complex rotation method, we have obtained evidence confirming the existence of the resonance and an estimate of its width of about 6 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}2}$ eV.
The "molecule" positronium hydride (PsH), consisting of one atom each of positronium and hydrogen, has one well-known particle-stable state of total energy $E=\ensuremath{-}1.575$ Ry. In addition, for each LLL it must have an infinite Rydberg series of excited states whose principal configuration is (${e}^{+}{\mathrm{H}}^{\ensuremath{-}}$), converging to a limit at $E=\ensuremath{-}1.0555$ Ry, the energy of ${\mathrm{H}}^{\ensuremath{-}}$. All of these excited states are energetically able to dissociate into ground-state Ps + H, and the higher-lying states can also decay with emission of excited Ps and ground-state H. These Rydberg states should appear as resonances in Ps + H scattering. In this paper I compute the lowest SSS-wave resonance parameters, using an optical-potential formalism based on the (${e}^{+}{\mathrm{H}}^{\ensuremath{-}}$) configuration. The results are in rough agreement with those previously obtained using Kohn variational or complex-rotation techniques with highly correlated trial functions. The physical description of the PsH excited states is thus clarified.
Positronium hydride (PsH)(\text{PsH})(PsH) is a weakly bound (molecular) state of two electrons $({e}^{\ensuremath{-}})$, a positron (e+)({e}^{+})(e+), and a proton (p+)({p}^{+})(p+). Due to the ${e}^{\ensuremath{-}}\ensuremath{-}{e}^{+}$ annihilation, it decays to a number of processes, where the radiationless decay is one of the most important channels. In this decay process, the photons released from the ${e}^{\ensuremath{-}}\ensuremath{-}{e}^{+}$ annihilation are absorbed by the remaining ${e}^{\ensuremath{-}}$ and p+{p}^{+}p+ in PsH, giving us $\text{PsH}\ensuremath{\rightarrow}{e}^{\ensuremath{-}}{p}^{+}$. For a particular spin (singlet) configuration of the constituents of PsH, the radiationless decay rate of PsH was determined by Aslam et al. [Phys. Rev. A 104, 052803 (2021)]. In this work, we calculate the decay rate of $\text{PsH}\ensuremath{\rightarrow}{e}^{\ensuremath{-}}{p}^{+}$ by exercising all possible spin orientations of PsH and the final states ${e}^{\ensuremath{-}}$ and p+{p}^{+}p+. By summing all the contributions, we verify that the result is the same if we calculate it using the standard fermion spin-sum technique of quantum field theory.
A doubly excited autodissociating resonant state in positronium hydride has been discovered, which is situated in a Rydberg series converging to the ${\mathrm{H}}^{\ensuremath{-}}(2{s}^{2})+{e}^{+}$ threshold. Previous research has noted a scarcity of such highly excited resonant states, particularly those with a doubly excited nature. The exploration of these states was made possible by employing a projection operator method supported by the stochastic variational method. Accurate calculations of the resonant positions and widths were performed using the complex coordinate rotation method with explicitly correlated Gaussians as basis functions. Our analysis has revealed the intrinsic structural characteristics of these highly excited states. The probability density distribution demonstrates that most resonant states of positronium hydride tend to favor either a ${\mathrm{H}}^{\ensuremath{-}}+{e}^{+}$ or ${\mathrm{Ps}}^{\ensuremath{-}}+{\mathrm{H}}^{+}$ configuration. However, two doubly excited resonant states exhibit a unique characteristic involving both the ${\mathrm{H}}^{\ensuremath{-}}+{e}^{+}$ and ${\mathrm{Ps}}^{\ensuremath{-}}+{\mathrm{H}}^{+}$ configurations. By integrating the probability density distribution with a quantum defect formula, highly excited resonances can be accurately assigned to either the ${\mathrm{H}}^{\ensuremath{-}}(2{s}^{2})+{e}^{+}$ or ${\mathrm{Ps}}^{\ensuremath{-}}(1{s}^{2})+{\mathrm{H}}^{+}$ Rydberg series, thereby reducing discrepancies compared to earlier classifications.