A simple qualitative description of EMC ratios \mu^A for 0.2 <~ x <~ 1.5 and some sample calculations

Abstract

We study EMC ratios on the basis of a relation between Structure Functions (SF) for a nucleus and for a nucleon, which is governed by a SF f^{PN,A}(x,Q^2) of an unphysical nucleus, composed of point-nucleons. We demonstrate that the characteristic features of EMC ratios \mu^A are determined by the above f^{PN,A} and the SF of free nucleons. We account for the positions of the points x_{1,2} in the interval 0.2 <~ x <~ 0.9, where \mu^A(x,Q^2)=1 and also for the minimum x_m in that interval. We similarly describe the oscillations in \mu^A for Q^2 <~ (3.5-4.0) GeV^2 in the Quasi-Elastic peak region 0.95 <~ x <~ 1.05 and for its subsequent continuous increase up to x\approx 1.4. Finally we compute \mu^A over the entire range above for A=^4He, C, Fe and Au and several Q^2 values. The results are in reasonable agreement with both directly measured and indirectly extracted data.