Extraction of the neutron structure function F2n from inclusive scattering data on composite nuclei

We consider a generalized convolution, linking structure functions (SF) FN2 for nucleons, FA2 for a physical nucleus and fPN,A for a nucleus, composed of point-nucleons. In order to extract F2n we employ data on F2p,A and the computed fPN,A. Only for Q2≈3.5 GeV2 do data permit the extraction of F2A(x,3.5) over a sufficiently wide x-range. Applying Mellin transforms, the above relation between SF turns into an algebraic one, which one solves for the Mellin transform of the unknown F2n. We present inversion methods leading to the desired F2n, all using a parametrization for C(x,Q2)=F2n(x,Q2)/F2p(x,Q2). Imposing motivated constraints, the simplest parametrization leaves one free parameter C(x=1,Q2). For Q2=3.5 GeV2 its average over several targets and different methods is 〈C(1,3.5)〉=0.54±0.03. We argue that for the investigated Q2, C(x→1,3.5) is determined by the nucleon-elastic (NE) part of SF. A calculation of the latter comes close to the extracted value. Both are close to the SU(6) limit uV(x,3.5)=2dV(x,3.5) for parton distribution functions.