CAA Run E1C

Spokespersons

M. Osipenko, G. Ricco

Year

2003

Abstract

We measured the inclusive electron-proton cross section in the nucleon resonance region (W<2.5 GeV) at momentum transfers Q2 below 4.5 (GeV/c)2 with the CLAS detector. The large acceptance of CLAS allowed the measurement of the cross section in a large, contiguous two-dimensional range of Q2 and x, making it possible to perform an integration of the data at fixed Q2 over the significant x interval. From these data we extracted the structure function F2 and, by including other world data, we studied the Q2 evolution of its moments, Mn(Q2), 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 will require significant improvements in theoretical predictions if a meaningful comparison with these new experimental results is to be made.

Comment

The date were obtained from a comined analysis of five different beam energy settings: 1.5, 2.5, 4.0 and 4.4 GeV. The final structure functions are corrected for bin size effect and therefore correspond to an infinitely narrow bins.

Publications

1. M. Osipenko, G. Ricco, M. Taiuti, M.Ripani, S. Simula, and CLAS Collaboration Kinematically complete measurement of proton structure function F2 in the resonance region and evaluation of its moments // Phys. Rev. D67, 092001 (2003)
2. M. Osipenko and CLAS Collaboration // CLAS-NOTE-2003-001

Quantities

F₂

Measurements