Janečková, Radmila Kubala, Dušan May, Olivier Fedor, Juraj Allan, Michael 2013-11-20 Two mechanisms for dissociative electron attachment in HCOOH, the formation of HCOO−+H, were proposed in the literature: (i) via a direct electron attachment into a σ∗ resonance, augmented by dipole binding of the incident electron [G. A. Gallup <i>et al.</i>, Phys. Rev. A 79, 042701 (2009)], and (ii) with the 1.8 eV π∗ resonance as a doorway state, linked to the products by symmetry lowering–distortion of the temporary anion, primarily the CH bond, from the planar symmetry [T. N. Rescigno <i>et al.</i>, Phys. Rev. Lett. 96, 213201 (2006)]. The later mechanism implies a reduction of the cross section upon deuteration of the hydrogen bonded to the C atom, whereas the former mechanism would leave the cross section unaffected. Our experimental absolute cross sections for the four isotopomers of formic acid show that deuteration on the C atom reduces the cross section value only marginally (by 12%) compared to deuteration on the O atom (reduction by a factor of 16), and thus favor mechanism (i). application/pdf https://folia.unifr.ch/global/documents/303378 https://folia.unifr.ch/documents/303378/files/all_eem.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevLett.111.213201 info:eu-repo/semantics/openAccess License undefined Physical Review Letters. - 2013, vol. 111, no. 21, p. 213201 info:eu-repo/classification/udc/54 Experimental evidence on the mechanism of dissociative electron attachment to formic acid http://purl.org/coar/resource_type/c_6501