We have shown that the lowest order QCD amplitude, i.e. the quark exchange contribution, to the forward production of a pair of longitudinally polarized ρ mesons in the scattering of two virtual photons γ(Q1)γ(Q2) → ρ0 Lρ L factorizes in two different ways: the part with transverse photons is described by the QCD factorization formula involving the generalized distribution amplitude of two fina...

We give a brief overview of the status of perturbative QCD calculations for deep-inelastic scattering. The radiative corrections to the Wilson coefficients are generally available to next-to-next-to-leading order in QCD and we address the accuracy of the strong coupling constant, the parton distributions of the nucleon and the heavy quark masses which is required for precision predictions. We a...

Perturbative NLO and NNLO QCD evolutions of parton distributions are studied, in particular in the (very) small-x region, where they are in very good agreement with all recent precision measurements of F p 2 (x,Q 2). These predictions turn out to be also rather insensitive to the specific choice of the factorization scheme (MS or DIS). A characteristic feature of perturbative QCD evolutions is ...

We consider the collinear limit of QCD amplitudes at one-loop order, and their factorization properties directly in colour space. These results apply to the multiple collinear limit of an arbitrary number of QCD partons, and are a basic ingredient in many higher-order computations. In particular, we discuss the triple collinear limit and its relation to flavour asymmetries in the QCD evolution ...

We present the calculation of the next-to-leading order QCD corrections to electroweak pp→ eνe μ μjj and pp→ eν̄e μ μjj production at the CERN LHC in the form of a fully flexible parton-level Monte Carlo program. The QCD corrections to the total cross sections are modest, changing the leading-order results by less than 10%. At the Born level, the shape of kinematic distributions can depend signi...

We propose studying the mechanism of factorization in exclusive decays of the form B → D(∗)X by examining the differential decay rate as a function of the invariant mass of the light hadronic state X. If factorization works primarily due to the large Nc limit then its accuracy is not expected to decrease as the X invariant mass increases. However, if factorization is mostly a consequence of per...

We study the normalization of perturbative QCD corrections to the inclusive B → Xsγ decay. We propose to set the renormalization scale using the Brodsky-Lepage-Mackenzie (BLM) method. In the proposed method the scale is determined by absorbing the vacuum polarization correction from light fermions to renormalization scale but not including the anomalous dimensions. The BLM scale depends in gene...

We propose studying the mechanism of factorization in exclusive decays of the form B → D(∗)X by examining the differential decay rate as a function of the invariant mass of the light hadronic state X. If factorization works primarily due to the large Nc limit then its accuracy is not expected to decrease as the X invariant mass increases. However, if factorization is mostly a consequence of per...

As a stringent test of the nonrelativistic QCD factorization approach for inclusive heavy-quarkonium production in high-energy hadron collision, the polarized heavyquarkonium production at the Tevatron is discussed. The polarization of prompt J/ψ at the Tevatron is predicted within the nonrelativistic QCD factorization framework. The contribution from radiative decays of P-wave charmonium state...

A QCD analysis of the world data on inclusive polarized deep inelastic scattering of leptons on nucleons is presented in leading and next–to–leading order. New parameterizations are derived for the quark and gluon distributions and the value of αs(MZ) is determined. Emphasis is put on the derivation of fully correlated error bands for these distributions which are directly applicable to determi...