Experimental tests of QCD at hadronic colliders

We present a general overview of recent QCD results at hadronic colliders. 1 Proton structure function measurements 1.1 Structure function measurements at HERA The H1 and ZEUS experiments at HERA, at DESY, Hamburg, Germany allow to probe directly the quark and gluon contents of the proton by measuring F 2 , the proton structure function in bins of x, the proton momentum fraction carried by the struck quark and Q 2 , the squared energy transferred at the lepton vertex. The advantage of an ep collider is that different methods are available to measure x and Q 2 using either the lepton or the jets in the final state or both. The kinematical plane reached by the HERA collaborations is given in Fig. 1. We notice that the proton structure can be probed over a large kinematical plane (10 −6 < x, 0.1 < Q 2 < 3.10 4), and has a common domain with the previous fixed target experiments (SLAC, BCDMS, NMC...), which allows a direct comparisons of the measurements. The proton structure function F 2 measurement 1 is given in Fig. 2. We notice the high precision of the measurement performed at HERA, in good agreement with the fixed target data. The lowest HERA Q 2 data benefit from a good acceptance of the calorimeters at low Q 2 (SPACAL for H1, and Beam Pipe Calorimeter for ZEUS) and from special runs with shifted positions of the interaction vertex which allow to measure lower angles for the scattered electrons, and thus lower Q 2 events. At moderate Q 2 and high x (0.015 < x < 0.65, 1 < Q 2 < 100 GeV 2), the NuTeV collaboration 2 has recently released new measurements of the proton structure functions F 2 and xF 3 with high precision, in agreement with QCD expectations.