Reply to A. Zecca’s Comment on ‘Positron scattering in helium: Virtual-positronium resonances’ by G.P. Karwasz, D. Pliszka, A. Zecca, R.S. Brusa [Nucl. Instr. and Meth. B 240 (2005) 666]

Zecca [this issue] makes a-posteriori operations on experimental data for positron–helium scattering [G.P. Karwasz, D. Pliszka, A. Zecca, R.S. Brusa, Nucl. Instr. and Meth. B 240 (2005) 666], instead of performing independent checks and tests on He and other light gases. We find his judgments on a hypothetical background due to the ion-feedback and on the energy resolution not fully documented. Awaiting independent experimental verification, we stress again the as-far-as-possible accuracy and completeness of apparatus settings, pre-and post-experiment checks and measurement procedures in the Ar and He experiment by Karwasz, Pliszka and Brusa.