Sandra J. Quintanilla

Previous Scheduled Teaching

Published Intellectual Contributions

Abstract for a conference

• Ward, S.J., Van Reeth, P. (2016). Deep Minimum in the Differential Cross Section for Ps Formation in Positron-Hydrogen Collisions. 61 (8) 193.

Abstract for a national conference

• DeMars, C.M., Kent, J.B., Ward , S.J. (2019). Deep minimum in the Coulomb-Born TDCS for e$^-$-He and e$^+$-He ionization. Bulletin of the American Physical Society. 64 (4) L01 13, 119 (1 pp)). http://meetings.aps.org/Meeting/DAMOP19/Session/L01.13
• Ward , S.J., Alrowaily, A.W., Van Reeth, P. (2019). Multichannel Effective Range Theory Analysis of Zeros in the Positronium formation Scattering Amplitude for Positron-Hydrogen Collisions. Bulletin of the American Physical Society. 64 (4) E01 32, 50-51 (2 pp). American Physical Society. http://meetings.aps.org/Meeting/DAMOP19/Session/E01.32
• Medrano, G., Ward , S.J., Van Reeth, P. (2019). Variational Calculations of the Ps-Ps System. Bulletin of the American Physical Society. 64 (4) S01 25, 193 (1pp). http://meetings.aps.org/Meeting/DAMOP19/Session/S01.2

Abstracts and Proceedings

• Ward Quintanilla, S.J., Mitchell, W. The Photodetachment Cross Section of Ps- and Elastic e^--Ps Scattering. Bulletin of the American Physical Society. 68 (7)
• Ward Quintanilla, S.J., DeMars, C.M. (2023). Deep minima in the Coulomb-Born triply differential cross sections for electron and positron ionization of hydrogen and helium. Bulletin of the American Physical Society. 68 (7) https://meetings.aps.org/Meeting/DAMOP23/Session/K04.3
• Ward Quintanilla, S.J. (2023). Electron-Positronium Scattering and the Photodetachment of the Positronium Negative Ion. https://meetings.aps.org/Meeting/GEC23/Session/GT3.1
• Ward Quintanilla, S.J., Mitchell, W. (2023). Photodetachment of the Positronium Negative Ion (Ps$^-$) and the $^1$D-wave e$^-$-Ps scattering. Bulletin of the American Physical Society. 68 (7) https://meetings.aps.org/Meeting/DAMOP23/Session/N01.22
• Ward, S.J., Mitchell, W.J. (2022). $^{1,3}S$ and $^{1,3}P$ electron-positronium scattering. Bulletin of the American Physical Society. 67 (7) Abstract F01.00021. Dept of Physics
• DeMars, C.M., Claypool, J., Ward Quintanilla, S.J., Van Reeth, P. (2021). Comparison of elastic scattering of electron, positron and positronium from helium. Bulletin of the American Physical Society. 66 (Number 6) V01.00017. American Physical Society. https://meetings.aps.org/Meeting/DAMOP21/Session/V01.17
• DeMars, C.M., Josiah, C.J., Ward, S.J., Van Reeth, P. (2021). Comparison of phase shifts and cross sections as a function of velocity for positron, electron and positronium elastic scattering from helium. Bulletin of the American Physical Society. 66 (Number 7) GT61.00061. American Physical Society. https://meetings.aps.org/Meeting/GEC21/Session/GT61.61
• Mitchell, W.J., Ward Quintanilla, S.J. (2021). Singlet p-wave elastic electron-positronium scattering}". Bulletin of the American Physical Society. 66 (Number 7) GT61.00071. American Physical Society. https://meetings.aps.org/Meeting/GEC21/Session/GT61.71
• Quintanilla, S.J., Medrano, G., Van Reeth, P.J. (2021). Variational calculations of the bound-state energy of Ps$_2$. Bulletin of the American Physical Society. 66 (Number 6) N01.00002. American Physical Society. https://meetings.aps.org/Meeting/DAMOP21/Session/N01.2
• DeMars, C.M., Ward, S.J., Kent, J.B. (2020). Deep minima in the Coulomb-Born triply differential cross section for electron and positron ionization of hydrogen and helium. Bulletin of the American Physical Society. 65 (4) American Physical Society. http://meetings.aps.org/Meeting/DAMOP20/Session/Q01.26
• DeMars, C.M., Ward, S.J., Kent, J.B. (2020). Deep minima in the Coulomb-Born triply differential cross section for electron and positron ionization of hydrogen and helium. Bulletin of the American Physical Society. http://meetings.aps.org/Meeting/GEC20/Session/LT1.3
• Ward, S.J., Alrowaily, A.W., Van Reeth, P. (2020). Deep minimum in the Ps-formation differential cross section for positron-helium collisions in the Ore Gap. Bulletin of the American Physical Society. 65 (4) http://meetings.aps.org/Meeting/DAMOP20/Session/E01.28
• S. J. Ward, Denton Woods, and P. Van Reeth. (2015). An Investigation of Positronium-Hydrogen Collisions. 60 (7) 182-183. http://meetings.aps.org/link/BAPS.2015.DAMOP.Q1.112
• S. J. Ward and J. H. Macek. (2014). http://meetings.aps.org/link/BAPS.2014.DAMOP.Q1.37
• S. J. Ward and J. H. Macek. (2014). http://meetings.aps.org/link/BAPS.2014.GEC.MW1.7
• Denton Woods, P. Van Reeth and S. J. Ward. (2014). http://meetings.aps.org/link/BAPS.2014.DAMOP.Q1.55
• S. J. Ward and J. H. Macek. (2013). Deep minimim in the Coulomb-Born TDCS for inner-shell ionization of carbon by electron impact. http://meetings.aps.org/link/BAPS.2013.GEC.HW1.19
• S. J. Ward and J. H. Macek. Investigation of a vortex in Coulomb-Born calculations of inner-shell ionization of carbon by electron impact. Since I decided not to attend the meeting, I withdrew the abstract. It did not appear in the online bulletin which APS consider as the published bulletin. Only appeared in hard-copy of bulletin..
• S. J. Ward. (2013). Positron Collisions from Simple Atoms and Positronium-Hydrogen Collisions. http://meetings.aps.org/link/BAPS.2013.GEC.KW5.1
• Denton Woods, S. J. Ward and P. Van Reeth. (2013). Variational Calculations of Low-Energy Elastic Ps-H Scattering. http://meetings.aps.org/link/BAPS.2013.DAMOP.Q1.122
• Denton Woods, S. J. Ward and P. Van Reeth. (2012). Low-energy S- and P-wave Positronium-Hydrogen Collisions.
• S. J. Ward and J. Shertzer. (2011). Hyperspherical hidden crossing calculation of Ps formation in low-energy e^+-Na collisions.
• D. Woods, S. J. Ward and P. Van Reeth. (2011). Low-Energy S-Wave Positronium-Hydrogen Collisions.
• S. J. Ward and J. H. Macek. (2011). Vortices in Coulomb-Born calculations for inner-shell ionization of carbon by electron-impact.
• Janine Shertzer and S. J. Ward. (2010). Binding Energy and Geometry of e^+Na.
• D. Woods, S. J. Ward and P. Van Reeth. (2010). The Binding Energy of PsH.
• Janine Shertzer and S. J. Ward. (2009). Binding Energy Calculations for e^+Li and e^+Na.
• S. J.Ward, J. H. Macek and S. Yu. Ovchinnikov. (1997). "The Hidden Crossing Method Applied toPositroniumFormation".
• S.J.Ward. (1993). "RecentDevelopmentsinthe TheoryofPositron-Hydrogen Collisions".
• R.P. McEachran, M. Horbatsch, A. D. Stauffer and S. J. Ward. (1990). "Positron-AlkaliAtom Scattering".
• M. Horbatsch, S. J.Ward, McEachran and A. D. Stauffer. (1990). "Resonances inPositron-Alkali Close-Coupling Calculations".
• A. D. Stauffer, K. Bartschat, R. I. Campeanu, M. Horbatsch, R.P. McEachran, L. A.Parcell and S. J.Ward. (1990). "Theoretical Calculations of Positron Collisions with Atoms".
• S.J.Ward,J.W.Humberstonand M. R. C. McDowell. (1986). "The ScatteringofLow-Energy ElectronsbyPositronium".

Journal Article

• Alrowaily, A.W., Ward, S.J., Van Reeth, P. (2021). Deep Minimum and a Vortex for Positronium Formation in Low-Energy Positron-Helium Collisions. ATOMS. 9 56. MDPI. https://www.mdpi.com/2218-2004/9/3/56
• DeMars, C.M., Ward, S.J., Colgan, S.J., Amami, S., Madison, D.H. (2020). Deep Minima in the Triply Differential Cross Section for Ionization of Atomic Hydrogen by Electron and Positron Impact. 8(2) 26 (12 pages). MDPI. https://www.mdpi.com/2218-2004/8/2/26
• DeMars, C.M., Kent, J.B., Ward, S.J. (2020). Deep minima in the Coulomb-Born triply differential cross sections for ionization of helium by electron and positron impact. The European Physical Journal D. 74 48 (pages 1-8). SpringerLink. https://link.springer.com/article/10.1140/epjd/e2019-100512-x
• Alrowaily, A.W., Ward , S.J., Van Reeth, P. (2019). Deep minima and vortices for positronium formation in low-energy positron-hydrogen collisions. Journal of Physics B: Atomic, Molecular and Optical Physics. 52 205201 (11pp). Bristol, Institute of Physics.
• Alrowaily, A.W., Ward, S.J., Van Reeth, P. Vortices for Positronium Formation in Low-Energy Positron-Hydrogen Collisions. Physical Review A. 23. https://journals.aps.org/pra/
• Van Reeth, P., Woods, D., Ward, S.J., Humberston, J.W. (2016). Corrigendum: Comparison of positronium, positron and electron scattering. Journal of Physics B: Atomic, Molecular and Optical Physics. 49 169501 (1pp).
• Van Reeth, P., Woods, D., Ward, S.J., Humberston, J.W. (2016). Comparison of positronium, positron and electron collisions with hydrogen at low velocities. Journal of Physics B: Atomic, Molecular and Optical Physics. 49 114001.
• Woods, D., Ward, S.J., Van Reeth, P. (2015). Detailed investigation of low-energy positronium-hydrogen scattering. Physical Review A. 92 022713-1 -- 022713-17. http://journals.aps.prg/pra
• Ward, S.J., Macek, J.H. (2014). Effect of a vortex in the triply differential cross section for electron impact K-shell ionization of carbon. 90 062709. http://journals.aps.org/pra/
• S. J. Ward and J. Shertzer. Hyperspherical Hidden Crossing Method Applied to Ps(1s)-Formation in Low-Energy e^+-H, e^+-Li and e^+-Na Collisions,.
• J. Shertzer and S. J. Ward. (2010). Binding Energy and Structure of e^+Na,.
• Krista Jansen,S.J.Ward,J. ShertzerandJ.H. Macek. (2009). "Absolute Cross Section for Positron-Impact Ionization of Hydrogen Near Threshold".
• Krista Jansen, S. J.Ward,. (2008). "Near-ThresholdPositron Impact Ionization of Hydrogen".
• S. J.Ward, J. Shertzer, S.Yu. Ovchinnikov and J. H. Macek. (2007). "Optimizing the Paths for Including the Correction Term to the Hyperspherical Hidden Crossing Method: Application to Formationine+ -Li Collisions".
• S.J.Ward. (2007). "The Photodetachmentof Ps− and Low-Energye+ -H Collisions".
• J. Shertzer and S. J.Ward. (2006). "Binding Energy and Structure of e+ Li and e− Li using a Parametric Model Potential".
• S. J.Ward and J. Shertzer. (2005). "PositroniumFormation Cross Section forPositron-Lithium Collisions".
• S. J.Ward and J. Shertzer. (2004). "E ff ect of the Core Polarization Term on Ps Formation in Low-Energy e+ -Li Collisions".
• J. Sandstr¨om,G. Haeffler, I. Kiyan, U. Berzinsh, D. Hanstorp, D. J.Pegg, J. C. Hunnell and S. J.Ward. (2004). "E ff ectofPolarizationon Photodetachment Thresholds".
• S. J.Ward and J. Shertzer. (2003). "ApplicationoftheHyperspherical Hidden Crossing MethodtoPositron-Lithium Collisions".
• S. J.Ward. (2002). "Positronium Formation in Low-Energy Positron Collisions with One-and Two-Electron Atoms".
• S.J.Ward,J.C. HunnellandJ.H. Macek. (2002). "The E ff ect of thePolarizationPotential on Low-EnergyAtomic Processes".
• S. J. Ward and J. H. Macek. (2000). "E ff ective Range Analysis of Positron-Hydrogen Collisions".
• S.J.Ward,J.H. Macek and S.Yu.. (1999). "Applicationof the Hidden Crossing Method to Positronium Formation".

Other

• Ward , S.J., Alrowaily, A.W., Reeth, P.V. (2018). Vortices for Ps formation in positron-hydrogen collisions Acceptance in the Ore Gap. Bulletin of the American Physical Society. 63 (No. 5) T01 31 pg 189. American Physical Society. http://meetings.aps.org/Meeting/DAMOP18/Session/T01.31
• Ward, S., Kent, J.B. (2017). Deep minimum in the Coulomb-Born TDCS for electron-impact ionization of atomic hydrogen. Bulletin of the American Physical Society. 62 (Issue Number 10) 28 (GT1 1). http://meetings.aps.org/Meeting/GEC17/Session/GT1.1
• Ward, S.J., Van Reeth, P., Alrowaily, A.W. (2017). Vortices for Ps formation in positron-hydrogen collisions. Bulletin of the American Physical Society. 62 (Issue Number 8) 137 (K1 148). American Physical Society. http://meetings.aps.org/Meeting/DAMOP17/Session/K1.148

Popular Press Article

• Krista Jansen,S.J.Ward,J. Shertzerand J.H. Macek. (2008). "Absolute Cross Section forPositron Impact Ionization of Hydrogen Near Threshold".
• Krista Jansen, S. J.Ward, J. Shertzer and J. H. Macek. (2007). "Near ThresholdPositron Impact Ionization of Hydrogen".
• Janine Shertzerand SandraWard. "Binding Energy of e+ Li usingthePeachModelPotential".
• Janine Shertzer and Sandra Ward. "Hyperspherical Hidden Crossing Calculation of PsFormation Cross Section for Low-Energy e+ -Li Collisions".
• James Sternberg, S. J. Ward, J. H. Macek and J. Shertzer. "Higher Order Corrections toWannier Threshold Law forPositron Scattering".
• S.Ward andJ. Shertzer. (2003). "The Application of the Hyperspherical Hidden Crossing Method toPositroniumFormation inPositron-Lithium Scattering".
• J.Ward and J. Shertzer. (2002). "Hyperspherical Hidden Crossing CalculationofPositron-Lithium Collisions".
• J. C. Hunnell, S. J.Ward, J. Sandstrom - D. Hanstorp and D. J.Pegg. (2002). "Photodetachment of Alkali Negative Ions".
• S. J.Ward. (2001). "E ff ective Range Theory Analysis ofPositron-Helium Collisions".
• S. J.Ward and J. H. Macek. (2000). "Virtual State of thePositronium-Proton System".
• S. J.Ward and J. H. Macek. (1999). "Analysis of Positron-Hydrogen Collisions using an E ff ective Range Theory".
• S.J.Ward,J.H. Macekand S.Yu. Ovchinnikov. (1998). "Hidden Crossing Method AppliedtoPositroniumFormation".
• S. J.Ward, J. H. Macek and S.Yu. Ovchinnikov. (1998). "Hidden Crossing Theory Applied to Ps-formation inPositron-Hydrogen Collisions".
• S. J.Ward, E. G. Roth, B. N. Guo, D. E. Golden and D. W. Mueller. (1997). "Anti-Capture to the Continuum via a Double Collision Mechanism in (e,2e) Collisions".
• S. J.Ward, J. H. Macek and S.Yu. Ovchinnikov. (1997). "The Hidden Crossing Method Applied toPositroniumFormation".
• S.J.Ward, J. H. Macek and S.Yu. Ovchinnikov. (1996). "The Hidden Crossing Method Applied to Positronium Formation".
• S.J.Ward. (1995). "Recent Developmentin the TheoryofFastPositron-Atom Collisions".
• S. J.Ward and J. H. Macek. (1994). "PositroniumFormationbyElectronic Capture from Hydrogenic Ions".
• S.J.Ward andJ.H. Macek. (1994). "Single and Double Photoionizationof Helium".
• S.J.WardandJ.H. Macek. (1994). "WaveFunctionsforContinuum Statesof ChargedFragments".
• S. J. Ward and J. H. Macek. (1991). "A Variational Principle for Time-Dependent Interactions".
• S.J.Ward,M. Horbatsch,R.P. McEachranandA.D. Stauffer. (1989). "Close-Coupling ApproachtoPositron Scattering for Lithium, Sodium andPotassium".
• S.J.Ward,M. Hor¬batsch, R. P. McEachran and A. D. Stauffer. (1989). "Close-Coupling CalculationsofLow-EnergyPositron-Alkali Collisions".
• S.J.Ward,M. Horbatsch, R.P. McEachran and A. D. Stauffer. (1989). "ResonancesinLow-EnergyPositron ScatteringfromLi,NaandK".
• S.J.Ward,M. Horbatsch, R.P. McEachran and A. D. Stauffer. (1988). "Close-coupling ApproachtoPositron Scattering fromPotassium".
• S.J.Ward,M. Hor¬batsch,R.P. McEachranandA.D. Stauffer. (1988). "Theoretical StudiesofLow-EnergyPositron-AlkaliAtom Scattering".
• S. J. Ward, J. W. Humberston and M. R. C. McDowell. (1987). "Elastic Scattering of Electrons (or Positrons) from Positronium and the Photodetachment of the Positronium Negative Ion".
• S. J.Ward, J. W. Hum¬berston and M. R. C. McDowell. (1986). "The Photodetachment of the Negative Ion ofPositronium (Ps−)".
• S.J.Ward,J.W. Hum¬berston and M. R. C. McDowell. (1985). "The ScatteringofLow-Energy S-Wave ElectronsbyPositronium".

Contracts, Grants and Sponsored Research

Grant - Research

• Ward, S.J., "Low-energy atomic processes including ones involving a positron," sponsored by National Science Foundation, Federal, $100000 Funded. (2022 - 2025).
• Ward (Quintanilla), S.J. (Principal), "Theoretical Investigation of Low-Energy Positron and Positronium Collisions," sponsored by National Science Foundation, Federal, $90992 Funded. (2017 - 2021).
• Ward Quintanilla, S., "Positronium-positronium scattering," sponsored by Physics Department, University of North Texas, University of North Texas, $3469.02 Funded. (2017 - 2017).
• Quintanilla, S.J. (Principal), "Theoretical Investigation of Low-Energy Positron and Positronium Collisions," sponsored by National Science Foundation, FED, Funded. (2017 - 2021).