An improved version of the Glauber-eikonal amplitude for electron-molecule scattering, originally developed by Bhattacharyya and Ghosh, that includes the effects of nonspherical potential terms up to =6 is presented. Application is made to e-H2 scattering at intermediate energies to test a recently proposed, parameter-free, correlation-polarization potential. This potential is based, as suggested by OConnell and Lane, on the hybridization of local-electron-gas theory and the long-range polarization. Results obtained are found to be very encouraging. © 1985 The American Physical Society.

P K BHATTACHARYYA

D K SYAMAL

B C SAHA

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Physical Review A

Pure elastic scattering (J=0J=0 and J=1J=1), rotational excitation (J=0J=2 and J=1J=3), and average elastic (pure elastic plus rotational excitation) cross sections of the hydrogen molecule by 1200-eV positrons are computed by using the adiabatic approximation in which the Glauber-type eikonal amplitude for a fixed molecular orientation is considered as input. Both differential and total scattering cross sections are calculated. Momentum-transfer cross sections are also obtained. Two different model effective potentials for positron hydrogen-molecule interactions have been considered. Effects of positronium formation channel are neglected. Comparison is made with the recent measurements as well as with the available theoretical calculations. Below the positronium formation threshold average total elastic-scattering cross sections are found to reproduce the experimental data quite accurately. Electron and positron scattering cross sections at intermediate energies are compared. The effects of polarization interaction are found to be significant even at 200 eV. © 1984 The American Physical Society.

Elastic and rotational excitation of the hydrogen molecule by 1200-eV positron impact

A tractable form of the Glauber eikonal amplitude for electron-molecule scattering is obtained with an effective complex potential. We report calculations of differential and integral cross sections for elastic scattering and pure rotational excitations, and of absorption cross sections (for sum of all electronic excitations and ionization processes) for e-H2 collisions at 40-100 eV. The absorption potential is modeled following Valone, Thirumalai, and Truhlar. It is found that rotationally summed elastic cross sections (integral) are reduced by about (3-5)% when absorption is considered and total cross sections (including absorption cross sections) agree well with available experimental measurements. © 1984 The American Physical Society.

Eikonal amplitude for electron-molecule collisions with effective complex potential: An application to H2

The Glauber-type eikonal amplitude for a fixed molecular orientation is used in the framework of adiabatic approximation to compute pure elastic excitation (J=1 J=1), rotational excitation (J=1J=3), and orientationally averaged elastic cross sections of the oxygen molecule in its ground electronic and vibrational states with the use of electrons as incident particles. Both differential and integral cross sections are reported at electron energies 20-200 eV. The effect of target polarization is included in the effective electron-molecule potential used, but that of electron exchange is neglected. The results are compared with the available experimental data and theoretical calculations of other workers. A comparative study of the molecules H2, N2, and O2 as targets is made. © 1983 The American Physical Society.

Elastic and rotational excitation of the oxygen molecule by intermediate-energy electrons

An adiabatic approximation in which the eikonal elastic amplitude for fixed molecular orientation is used as input is employed for the calculation of pure elastic scattering (J=0 J=0 and J=1, J=1) pure rotational excitation (J=0, J=2 and J=1, J=3), and orientationally averaged elastic cross sections of the nitrogen molecule in its ground electronic and vibrational states using electrons as incident particles. Both differential and integral cross sections are computed at electron energies 20-200 eV. Total momentum-transfer cross sections are also calculated. The effect of target polarization is considered in the effective electron-molecule potential. The effect of electron exchange is not taken into account. Results obtained are compared with those of other theoretical and experimental workers. The qualitative features of the rotational-excitation cross sections are found to resemble those of the hydrogen molecule. Small-angle experimental elastic cross sections are well reproduced. © 1982 The American Physical Society.

Elastic and rotational excitation of the nitrogen molecule by intermediate-energy electrons

The eikonal amplitude for a fixed molecular orientation is used in the framework of the adiabatic approximation to calculate pure elastic excitation (00 and 11), pure rotational excitation (02 and 13), and average elastic cross sections of the hydrogen molecule in its ground electronic and vibrational states using electrons as incident projectiles. Both differential and integral cross sections are reported at electron energies 20-200 eV. For elastic processes, the effects of target polarization and electron exchange are considered, while for inelastic processes only the effect of the target polarization is taken into account. Results obtained are compared with those of other theoretical and experimental workers. It is found that pure elastic and pure rotational excitation cross sections are comparable at intermediate and large scattering angles, and that they depend on the initial rotational state J of the molecule in such a way that the average elastic cross sections remain independent of J. © 1978 The American Physical Society.

Journal	Physical Review A
Publisher	-
ISSN	1050-2947