Special Issue "Positron Scattering and Annihilation with Atoms and Molecules including Emerging New Resonances and their Applications in other Systems"

A special issue of Atoms (ISSN 2218-2004).

Deadline for manuscript submissions: closed (31 January 2016)

Special Issue Editors

Guest Editor
Prof. Dr. Chi Yu Hu

California State University, Long Beach, Department of Physics & Astronomy, 1250 Bellflower Blvd., Long Beach, CA 90840-3901, USA
Website | E-Mail
Interests: Multichannel Faddeev-Merkuriev equation (MFE); Gailitis resonances (internal Stark resonances); practical applications of the Gailitis
Guest Editor
Dr. Anand K. Bhatia

Heliophysics Science Division, NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA
Website | E-Mail
Interests: scattering and annihilation of positrons and electrons; Feshbach resonances; Photoionization of atoms; muonic physics; Rydberg states; excitation of ions by electron and proton impact their applications to astrophysics; Photoionization; atomic structure calculations; Lamb shift

Special Issue Information

Dear Colleagues,

The low energy positron collisions and annihilation on atoms and molecules has had a long and very successful research record in both theoretical and experimental fronts. At energy above the positronium formation threshold, the progress was limited due to the inability to distinguish the direct positron annihilation from that due to positronium formation. This problem is solved beginning with the three-body scattering systems using the multi-channel Faddeev-Merkuriev equation (MFE). The complete solution of a six-open channel (S-partial wave) positron collision with hydrogen atom system provided detail information of the structures of resonances. Two types of resonances exist in this region. One type is identified as the well known Feshbach resonances. The second type has been identified to have a much different formation mechanism. It is named the Gailitis resonances. A series of Gailitis resonances occur when the incoming charged particle and the target atom with electric moments become correlated at certain distances via the internal Stark-effect. The life-time of these resonances can be very long when the center of mass collision energy is small. Such long-lived long range correlation can produce interesting physical effects. An earlier six-open channel, S-partial waves calculation showed enhanced anti-hydrogen formation cross section from the incoming channel anti-proton + positronium atom around the energy region of the Gailitis resonances. Recent theoretical calculation indicated the Gailitis resonance is able to provide an alternative route to muon catalyzed fusion. Low energy nuclear fusion can be explained when the condition for the formation of Gailitis resonance exists. The physical mechanism involved in the formation of Gailitis resonance is the universal Stark-effect. This Special Issue hopes to bring awareness of the Gailitis resonance to the larger physics communities. We invite authors to submit articles from all areas of physics.

Dr. Chiyu Hu
Dr. Anand K. Bhatia
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Atoms is an international peer-reviewed open access quarterly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 350 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (8 papers)

View options order results:
result details:
Displaying articles 1-8
Export citation of selected articles as:

Research

Open AccessArticle Positron-Hydrogen Scattering, Annihilation, and Positronium Formation
Atoms 2016, 4(4), 27; doi:10.3390/atoms4040027
Received: 14 September 2016 / Revised: 19 October 2016 / Accepted: 26 October 2016 / Published: 4 November 2016
Cited by 1 | PDF Full-text (433 KB) | HTML Full-text | XML Full-text
Abstract
In previous papers (Bhatia A.K. 2007, 2012) a hybrid theory for the scattering of electrons from a hydrogenic system was developed and applied to calculate scattering phase shifts, Feshbach resonances, and photoabsorption processes. This approach is now being applied to the scattering of
[...] Read more.
In previous papers (Bhatia A.K. 2007, 2012) a hybrid theory for the scattering of electrons from a hydrogenic system was developed and applied to calculate scattering phase shifts, Feshbach resonances, and photoabsorption processes. This approach is now being applied to the scattering of positrons from hydrogen atoms. Very accurate phase shifts, using the Feshbach projection operator formalism, were calculated previously (Bhatia A.K. et al. 1971 and Bhatia et al. 1974a). The present results, obtained using shorter expansions in the correlation function, along with long-range correlations in the Schrödinger equation, agree very well with the results obtained earlier. The scattering length is also calculated and the present results are compared with the previous results. Annihilation cross-sections, and positronium formation cross-sections, calculated in the distorted-wave approximation, are also presented. Full article
Figures

Figure 1

Open AccessArticle Series of Broad Resonances in Atomic Three-Body Systems
Atoms 2016, 4(2), 17; doi:10.3390/atoms4020017
Received: 27 January 2016 / Revised: 19 May 2016 / Accepted: 14 June 2016 / Published: 20 June 2016
PDF Full-text (1725 KB) | HTML Full-text | XML Full-text
Abstract
We re-examine the series of resonances found earlier in atomic three-body systems by solving the Faddeev-Merkuriev integral equations. These resonances are rather broad and line up at each threshold with gradually increasing gaps. This lining up takes place in the same way for
[...] Read more.
We re-examine the series of resonances found earlier in atomic three-body systems by solving the Faddeev-Merkuriev integral equations. These resonances are rather broad and line up at each threshold with gradually increasing gaps. This lining up takes place in the same way for all thresholds and is irrespective of the spatial symmetry. We relate these resonances to the Gailitis mechanism, which is a consequence of the polarization potential. Full article
Open AccessCommunication The Faddeev-Merkuriev Differential Equations (MFE) and Multichannel 3-Body Scattering Systems
Atoms 2016, 4(2), 16; doi:10.3390/atoms4020016
Received: 11 November 2015 / Revised: 20 April 2016 / Accepted: 20 April 2016 / Published: 3 May 2016
PDF Full-text (269 KB) | HTML Full-text | XML Full-text
Abstract
Numerical implementation of the modified Faddeev Equation (MFE) is presented in some detail. The Faddeev channel wave function displays unique properties of each and every open channel, respectively. In particular, near resonant energies, the structures of the resonances are beautifully displayed, from which,
[...] Read more.
Numerical implementation of the modified Faddeev Equation (MFE) is presented in some detail. The Faddeev channel wave function displays unique properties of each and every open channel, respectively. In particular, near resonant energies, the structures of the resonances are beautifully displayed, from which, the life-time of the resonances can be determined by simply using the uncertainty principle. The phase shift matrix, or the K-matrix, provides unique information for each and every resonance. This information enables the identification of the physical formation mechanism of the Gailitis resonances. A few of these resonances, previously known as the mysterious shape resonances, have occurred in a number of different collision systems. The Gailitis resonances are actually produced by a quantized Stark-effect within the various collision systems. Since the Stark-effect is a universal phenomenon, the Gailitis resonances are expected to occur in much broader classes of collision systems. We will present the results of a precision calculation using the MFE method in sufficient detail for interested students who wish to explore the mysteries of nature with a powerful theoretical tool. Full article
Open AccessArticle Relativistic Ionization of Hydrogen Atoms by Positron Impact
Atoms 2016, 4(1), 10; doi:10.3390/atoms4010010
Received: 30 December 2015 / Revised: 22 February 2016 / Accepted: 26 February 2016 / Published: 4 March 2016
PDF Full-text (4755 KB) | HTML Full-text | XML Full-text
Abstract
Relativistic triple differential cross-sections (TDCS) for ionization of hydrogen atoms by positron impact have been calculated in the symmetric coplanar geometry. We have used Dirac wave functions to describe free electron’s and positron’s sates. The relativistic formalism is examined by taking the non
[...] Read more.
Relativistic triple differential cross-sections (TDCS) for ionization of hydrogen atoms by positron impact have been calculated in the symmetric coplanar geometry. We have used Dirac wave functions to describe free electron’s and positron’s sates. The relativistic formalism is examined by taking the non relativistic limit. Present results are compared with those for the corresponding electron-impact case. In the first Born approximation, we found that the TDCS for positron impact ionization exceeds that for electron impact for all energies in accordance with the result obtained by several other theories. Full article
Figures

Open AccessArticle Merkuriev Cut-off in e+ H Multichannel Scattering Calculations
Atoms 2016, 4(1), 9; doi:10.3390/atoms4010009
Received: 9 December 2015 / Revised: 17 February 2016 / Accepted: 22 February 2016 / Published: 1 March 2016
PDF Full-text (1140 KB) | HTML Full-text | XML Full-text
Abstract
We present the results of positron-Hydrogen multichannel scattering calculations performed on the base of Faddeev-Merkuriev equations. We discuss an optimal choice of the Merkuriev’s Coulomb splitting parameters. Splitting the Coulomb potential in two-body configuration space is applicable for a limited energy range. Splitting
[...] Read more.
We present the results of positron-Hydrogen multichannel scattering calculations performed on the base of Faddeev-Merkuriev equations. We discuss an optimal choice of the Merkuriev’s Coulomb splitting parameters. Splitting the Coulomb potential in two-body configuration space is applicable for a limited energy range. Splitting the potential in three-body configuration space makes it possible to perform calculations in a broader range of energies and to optimize the numerical convergence. Scattering cross sections for zero total angular momentum for all processes between the positronium formation threshold and the third excitation threshold of the Hydrogen atom are reported. Full article
Open AccessArticle Second Order Stark-Effect Induced Gailitis Resonances in e + Ps and p + 7Li
Atoms 2016, 4(1), 8; doi:10.3390/atoms4010008
Received: 18 September 2015 / Revised: 4 February 2016 / Accepted: 4 February 2016 / Published: 26 February 2016
Cited by 1 | PDF Full-text (720 KB) | HTML Full-text | XML Full-text
Abstract
We present a detailed comparison between the first order Stark-effect induced Gailitis resonance in e+ + H (n = 2) and the second order Stark-effect induced resonance in e + Ps (n = 1). Common characteristics as well as differences
[...] Read more.
We present a detailed comparison between the first order Stark-effect induced Gailitis resonance in e+ + H (n = 2) and the second order Stark-effect induced resonance in e + Ps (n = 1). Common characteristics as well as differences of these resonances will be identified. These results will be used to assess the presence of Gailitis resonances in the scattering of proton on the ground state of 7Li atom. During the lifetime of the Gailitis resonance, nuclear fusion is enhanced by the resonant entry of the proton into the nucleus of 7Li via a compound nuclear energy level of 8Be*. Full article
Open AccessArticle Natural and Unnatural Parity Resonance States in the Positron-Hydrogen System with Screened Coulomb Interactions
Atoms 2016, 4(1), 3; doi:10.3390/atoms4010003
Received: 22 November 2015 / Revised: 20 December 2015 / Accepted: 22 December 2015 / Published: 26 December 2015
Cited by 7 | PDF Full-text (5725 KB) | HTML Full-text | XML Full-text
Abstract
In the present work, we report calculations of resonances in the positron-hydrogen system interacting with screened Coulomb potentials using the method of complex scaling together with employing correlated Hylleraas wave functions. Resonances with natural and unnatural parities are investigated. For the natural parity
[...] Read more.
In the present work, we report calculations of resonances in the positron-hydrogen system interacting with screened Coulomb potentials using the method of complex scaling together with employing correlated Hylleraas wave functions. Resonances with natural and unnatural parities are investigated. For the natural parity case, resonance parameters (energy and width) for D-wave resonance states with even parity lying below various positronium and hydrogen thresholds up to the H(N = 4) level are determined. For the unnatural parity case, results for P-even and D-odd resonance states with various screened Coulomb interaction strengths are located below different lower-lying Ps and H thresholds. Full article
Open AccessArticle Quantum Entanglement and Shannon Information Entropy for the Doubly Excited Resonance State in Positronium Negative Ion
Atoms 2015, 3(3), 422-432; doi:10.3390/atoms3030422
Received: 15 July 2015 / Revised: 7 September 2015 / Accepted: 10 September 2015 / Published: 21 September 2015
Cited by 2 | PDF Full-text (389 KB) | HTML Full-text | XML Full-text
Abstract
In the present work, we report an investigation on quantum entanglement in the doubly excited 2s21Se resonance state of the positronium negative ion by using highly correlated Hylleraas type wave functions, determined by calculation of the density of resonance
[...] Read more.
In the present work, we report an investigation on quantum entanglement in the doubly excited 2s2 1Se resonance state of the positronium negative ion by using highly correlated Hylleraas type wave functions, determined by calculation of the density of resonance states with the stabilization method. Once the resonance wave function is obtained, the spatial (electron-electron orbital) entanglement entropies (von Neumann and linear) can be quantified using the Schmidt decomposition method. Furthermore, Shannon entropy in position space, a measure for localization (or delocalization) for such a doubly excited state, is also calculated. Full article

Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Title: The Faddeev-Merkuriev differential equations(MFE) and multichannel 3-body scattering systems
Authors: Chi Yu Hu and David Caballero
Affiliation: Department of Physics and Astronomy, California State University, Long Beach California, U.S.A.
Abstract: Numerical implementation of the MFE is presented in some details. The Faddeev Channel wave functions display unique properties of each and every open Channels respectively. In particular, near resonant energies, the structures of the resonances are beautifully displayed, from which, the life-time of the resonances can be determined simply using the uncertainty principle. The phase shift matrix, or the K-matrix provides unique information for each and every resonance. These information enable the identification of the physical formation mechanism of the Gailitis resonances. A few of theses resonances, previously known as the mysterious shape resonances, have occurred in a number of different collision systems. The Gailitis resonances are actually produced by a quantized Stark-effect within the various collision systems. Since Stark-effect is an universal phenomenon, the Gailitis resonances are expected to occur in much broader classes of collision systems. We will present the results of a precision calculation using the MFE method in sufficient details for interested students who wish to explore the mysteries of nature with a powerful theoretical tool.
Keywords: multichannel- quantum scattering theory, Stark-effect, resonance

Title: Second order Stark-effect induced Gailitis resonances in e + Ps(l=0) and p + 7Li
Authors: Chi Yu Hu , Z. Papp and David Caballero
Affiliation: Department of Physics and Astronomy, Long Beach, California, U.S.A
Abstract: We present detailed comparison between the first order Stark-effect induced Gailitis resonance in e+ + H(n=2) and the second order Stark-effect induced resonance in e + Ps(l=0). Common characteristics, as well as the differences, of these resonances will be identified. Assessment of the presence of Gailitis resonance in p + 7Li and the subsequent nuclear fusion between the proton and the nucleus of 7Li will be discussed.
Keywords: multichannel quantum scattering theory,Stark-effect, Gailitis resonance

Journal Contact

MDPI AG
Atoms Editorial Office
St. Alban-Anlage 66, 4052 Basel, Switzerland
E-Mail: 
Tel. +41 61 683 77 34
Fax: +41 61 302 89 18
Editorial Board
Contact Details Submit to Atoms Edit a special issue Review for Atoms
logo
loading...
Back to Top