1207.0131 (V. Guzey et al.)

Impact of nuclear dependence of R=σ_L/σ_T on antishadowing in
nuclear structure functions    [PDF]

V. Guzey, L. Zhu, C. Keppel, M. Eric Christy, D. Gaskell, P. Solvignon, A. Accardi

We study the impact of the nuclear dependence of R=\sigma_L/\sigma_T on the extraction of the F_2^A/F_2^D and F_1^A/F_1^D structure function ratios from the data on the \sigma^A/\sigma^D cross section ratios. Guided by indications of the nuclear dependence of R from the world data, we examine selected sets of EMC, BCDMS, NMC and SLAC data and find that F_1^A/F_1^D < \sigma^A/\sigma^D \leq F_2^A/F_2^D. In particular, we observe that the nuclear enhancement (antishadowing) for F_1^A/F_1^D in the interval 0.1 < x < 0.3 becomes significantly reduced or even disappears, which indicates that antishadowing is dominated by the longitudinal structure function F_L. We also argue that precise measurements of nuclear modifications of R and F_L^A have the potential to constrain the poorly known gluon distribution in nuclei over a wide range of x.

View original: http://arxiv.org/abs/1207.0131