Application of the Schwinger multichannel formulation to electron-impact excitation of the BΣu+1state ofH2

In this paper we report cross sections for electron-impact excitation of the X ${\mathrm{}}^1$ ${\Sigma }_g^{+}$→B ${\mathrm{}}^1$ ${\Sigma }_u^{+}$ transition in ${\mathrm{H}}_2$ for collision energies of 15, 20, and 30 eV. For this dipole-allowed transition with its associated long-range potential, the contributions of the more strongly scattered low-angular-momentum partial waves to the cross section were obtained from a two-state Schwinger multichannel calculation, and a modified Born-closure scheme was used to include the contributions from the remaining weakly scattered partial waves. Agreement between the calculated differential cross sections and available experimental data is encouraging.