Measurements of R = $\sigma$(L)/sigma(T) for 0.03 < x < 0.1 and fit to world data.

The E143 collaboration Abe, K. ; Akagi, T. ; Anthony, P.L. ; et al.
Phys.Lett.B 452 (1999) 194-200, 1999.
Inspire Record 475305 DOI 10.17182/hepdata.28090

Measurements were made at SLAC of the cross section for scattering 29 GeV electrons from carbon at a laboratory angle of 4.5 degrees, corresponding to 0.03&lt;x&lt;0.1 and 1.3&lt;Q^2&lt;2.7 GeV^2. Values of R=sigma_L/sigma_T were extracted in this kinematic range by comparing these data to cross sections measured at a higher beam energy by the NMC collaboration. The results are in reasonable agreement with pQCD calculations and with extrapolations of the R1990 parameterization of previous data. A new fit is made including these data and other recent results.

1 data table

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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

No description provided.

Data from experiment E-140.

Global extracting of R from all the experiments.

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