arXiv subjects

J. N. L. Connor

Publications and source records attributed to J. N. L. Connor.

4 recordsLinked to original sources

arXiv2004

Numerical Evaluation of Cuspoid and Bessoid Oscillating Integrals for Applications in Chemical Physics

Oscillating integrals often arise in the theoretical description of phenomena in chemical physics, in particular in atomic and molecular collisions, and in spectroscopy. A computer code for the numerical evaluation of the oscillatory cuspoid canonical integrals and their first-order partial derivatives is described. The code uses a novel adaptive contour algorithm, which chooses a contour in the complex plane that avoids the violent oscillatory and exponential natures of the integrand and modifies its choice as necessary. Applications are made to the swallowtail canonical integral and to a bessoid integral.

physics.chem-ph↗

arXiv2004

Improved Nearside-Farside Decomposition of Elastic Scattering Amplitudes

A recently proposed technique is described that provides improved nearside-farside (NF) decompositions of elastic scattering amplitudes. The technique, involving a new resummation formula for Legendre partial wave series, reduces the importance of unphysical contributions to NF subamplitudes, which can appear in more conventional NF decompositions. Applications are made to a strong absorption model that arises in chemical and nuclear physics, as well as to a 16O + 16O optical potential at Elab = 132 MeV.

physics.chem-ph↗

arXiv2003

Nearside-farside theory of differential cross sections : resummation of a partial wave series involving Legendre polynomials

We report a new resummation procedure for the partial wave series (PWS) representation of the scattering amplitude, when a basis set of Legendre polynomials is used for the expansion. The effect of the resummation is to remove from the PWS the factor containing alpha and beta. The resummed scattering amplitude is then exactly decomposed into the sum of a nearside (N) subamplitude and a farside (F) subamplitude. We make two applications of the NF resummed theory: to elastic angular scattering in a strongly absorptive collision and to a state-to-state differential cross section for the I + HI > IH + I reaction. In both applications, we can understand the physical origin of structure in the angular scattering for suitable choices of alpha, beta and r.

physics.chem-ph↗

arXiv2001

Improved Nearside-Farside Decomposition of Elastic Scattering Amplitudes

A simple technique is described, that provides improved nearside-farside (NF) decompositions of elastic scattering amplitudes. The technique, involving the resummation of a Legendre partial wave series, reduces the importance of unphysical contributions to NF subamplitudes, which can arise in more conventional NF decompositions. Applications are made to a strong absorption model and to a $^{16}$O + $^{12}$C optical potential at $E_{\text{lab}} = 132$ MeV.

nucl-th↗