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A kinematically complete measurement of the proton structure function F2 in the resonance region and evaluation of its moments.

The CLAS collaboration Osipenko, M. ; Ricco, G. ; Taiuti, M. ; et al.

Phys.Rev.D 67 (2003) 092001, 2003.

Inspire Record 612145 DOI 10.17182/hepdata.12253

We measured the inclusive electron-proton cross section in the nucleon resonance region (W < 2.5 GeV) at momentum transfers Q**2 below 4.5 (GeV/c)**2 with the CLAS detector. The large acceptance of CLAS allowed for the first time the measurement of the cross section in a large, contiguous two-dimensional range of Q**2 and x, making it possible to perform an integration of the data at fixed Q**2 over the whole significant x-interval. From these data we extracted the structure function F2 and, by including other world data, we studied the Q**2 evolution of its moments, Mn(Q**2), in order to estimate higher twist contributions. The small statistical and systematic uncertainties of the CLAS data allow a precise extraction of the higher twists and demand significant improvements in theoretical predictions for a meaningful comparison with new experimental results.

46 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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A Reevaluation of the Gottfried sum

The New Muon collaboration Arneodo, M. ; Arvidson, A. ; Badelek, B. ; et al.

Phys.Rev.D 50 (1994) R1-R3, 1994.

Inspire Record 358419 DOI 10.17182/hepdata.71293

We present a new determination of the nonsinglet structure function ${\mathit{F}}_{2}^{\mathit{p}}$ - ${\mathit{F}}_{2}^{\mathit{n}}$ at ${\mathit{Q}}^{2}$=4 ${\mathrm{GeV}}^{2}$ using recently measured values of ${\mathit{F}}_{2}^{\mathit{d}}$ and ${\mathit{F}}_{2}^{\mathit{n}}$/${\mathit{F}}_{2}^{\mathit{p}}$. A new evaluation of the Gottfried sum is given, which remains below the simple quark-parton model value of 1/3.

4 data tables

Table 1

Errors of F2(D) are the estimated total uncertainties and those on the ratio and difference are statistical only.

Table 2

Values of the Gottfried Sum Rule integral (GS) defined as the integral between X(C=MIN) and X = 0.8 of (F2(P)-F2(N))DX/X.

Table 3

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A Precise extraction of R = sigma-L / sigma-T from a global analysis of the SLAC deep inelastic e p and e d scattering cross-sections

Whitlow, L.W. ; Rock, Stephen ; Bodek, A. ; et al.

Phys.Lett.B 250 (1990) 193-198, 1990.

Inspire Record 296980 DOI 10.17182/hepdata.29555

We report the extraction of R = σ L / σ T from a global analysis of eight SLAC deep inelastic experiments on e-p and e-d scattering performed between 1970 and 1985. Values of R p , R d , and R d − R p are determined over the entire SLAC kinematic range: 0.1⩽ x ⩽0.9 and 0.6⩽ Q 2 ⩽20.0 (GeV/ c ) 2 . We find that R p = R d . Measured values of R ( x , Q 2 ) are larger than predictions based on perturbative QCD and on QCD with the inclusion of kinematic target mass terms, indicating that dynamical higher twist effects may be important in the SLAC kinematic range.

13 data tables

Table 1

No description provided.

Table 2

Data from experiment E-140.

Table 3

Global extracting of R from all the experiments.