Momentum sum rule can be used as an inequality to estimate the lower and upper bounds of the momentum fractions of quarks and gluons in a model of proton valid in a limited \textit{ x} range. We compute such bounds in a self-similarity based model of proton structure function valid in the range $ 6.2\times 10^{ -7} \leq x \leq 10^{ -2} $. The results conform to the asymptotic QCD expectations.
Categories: hep-ph