Article révisé par les pairs
Résumé : A measurement of the derivative (∂ ln F2/∂ ln x)Q2 = -λ(x, Q2) of the proton structure function F2 is presented in the low x domain of deeply inelastic positron-proton scattering. For 5 × 10-5 ≤ x ≤ 0.01 and Q2 ≥ 1.5GeV2, λ(x, Q2) is found to be independent of jc and to increase linearly with In Q2. © 2001 Elsevier Science B.V. All rights reserved.