Regge oscillations in electron-atom elastic cross sections

Journal Article · Sun Jul 15 04:00:00 EDT 2007 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.76.012705· OSTI ID:21011222

Sokolovski, D ^[1]; Felfli, Z; Msezane, A Z ^[2]; Ovchinnikov, S Yu; Macek, J H ^[3]

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1. School of Mathematics and Physics, Queen's University of Belfast, Belfast, BT7 1NN (United Kingdom)
2. Center for Theoretical Studies of Physical Systems, Clark Atlanta University, Atlanta, Georgia 30314 (United States)
3. Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 (United States)

We consider a system trapped in a resonance state, whose decay at zero scattering angle can be related, through the optical theorem, to the total cross section (TCS). We show that for the resonance to contribute to the TCS a peak structure the resonance conditions must be satisfied: (i) Several rotations of the complex (the Regge trajectory--viz., imaginary part versus the real part of the complex angular momentum--stays close to the real axis) and (ii) coherent addition of forward-scattering subamplitudes (the real part of the Regge pole is close to an integer). We exploit the recent complex angular momentum approach of Macek et al. [Phys. Rev. Lett. 93, 183203 (2004)], used to analyze low-energy oscillations observed in the elastic TCS for proton-H scattering, for a detailed analysis of Regge trajectories and their contributions to the TCS in electron-atom scattering for the case of Z=75 using the model Thomas-Fermi potential. We conclude by demonstrating through comparison with existing theory and measurements that the Thomas-Fermi potential when used with the appropriate parameters captures the essential physics (Ramsauer-Townsend minima and the Wigner threshold law) in the near-threshold e-Ar and e-Kr elastic scattering.

• OSTI ID: 21011222
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 1 Vol. 76; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ANGULAR MOMENTUM
ARGON
CAPTURE
COMPARATIVE EVALUATIONS
DECAY
ELASTIC SCATTERING
ELECTRON-ATOM COLLISIONS
ELECTRONS
ION-ATOM COLLISIONS
KRYPTON
OPTICAL THEOREM
OSCILLATIONS
POTENTIALS
PROTONS
REGGE TRAJECTORIES
RESONANCE
ROTATION
THOMAS-FERMI MODEL
TOTAL CROSS SECTIONS
TRAPPING