Measurements of F_2 and xF_3(nu)-xF_3(nubar) from CCFR nu_mu-Fe and nubar_mu-Fe data in a physics model independent way

TL;DR

The ratio of the F2 (PMI) values measured in nu(mu) and mu scattering is in agreement (within 5%) with the predictions of next-to-leading-order parton distribution functions using massive charm production schemes, thus resolving the long-standing discrepancy between the two sets of data.

Abstract

We report on the extraction of the structure functions F_2 and Delta xF_3 = xF_3(nu)-xF_3(nubar) from CCFR nu_mu-Fe and nubar_mu-Fe differential cross sections. The extraction is performed in a physics model independent (PMI) way. This first measurement of Delta xF_3, which is useful in testingmodels of heavy charm production, is higher than current theoretical predictions. The ratio of the F_2(PMI) values measured in nu_mu and nubar_mu scattering is in agreement (within 5%) with the predictions of NLO PDFS using massive charm production schemes, thus resolvin long-standing discrepancy between the two sets of data.

Figures (4)

• Figure 1: Typical raw differential cross sections at $E_\nu=150$ GeV (both statistical and systematic errors are included). The CCFR data are in good agreement with the NLO TR-VFS QCD calculation using MRST99 PDFs (dashed line). The solid line is a CCFR LO QCD inspired fit.
• Figure 2: $\Delta xF_3$ data as a function of $x$ compared with various schemes for massive charm production:(left) TR-VFS(MRST99), ACOT-VFS(CTEQ4HQ), FFS(GRV94), and the CCFR-LO (a leading order model with a slow rescaling correction); (right) Sensitivity of the theoretical calculations to the choice of scale.
• Figure 3: The ratio of $F_2^{\nu}$ (PMI) data divided by $F_2^{\mu}$ (NMC or BCDMS) or $F_2^e$ (SLAC). Both statistical and systematic errors are included. Also shown are the predictions of the TR-VFS (MRST99), ACOT-VFS (CTEQ4HQ) and FFS (GRV94) heavy flavor calculations.
• Figure 4: The ratio of the previous $F_2^{\nu}$ (PMD) data divided by $(18/5)F_2^{\mu}$ (NMC or BCDMS) or $(18/5)F_2^e$ (SLAC). Shown are the predictions of the MRSR2 light-flavor PDFs (the curves with CTEQ4M are very similar).