Determination of αs from F2p at HERA

We compute the proton structure function F2p at small x and large Q2 at next-to-leading order in αs(Q2), including summations of all leading and subleading logarithms of Q2 and 1x. We perform a detailed comparison to the 1993 HERA data, and show that they may be used to determine αs(Mz2) = 0.120 ± 0.005(exp) ± 0.009(th). The theoretical error is dominated by the renormalization and factorization scheme ambiguities.