Related papers: Deviations from NLO QCD evolution in inclusive HER…
We compute the next-to-next-to-leading order (NNLO) QCD corrections to event shape distributions and their mean values in deep inelastic lepton-nucleon scattering. The magnitude and shape of the corrections varies considerably between…
It is performed for the first time a next-to-next-to-leading order analysis of deep inelastic structure functions $F_2$ and $F_L$ using the recently determined first moments of the non-singlet anomalous dimensions and the corresponding…
The QCD analysis of deep inelastic diffractive scattering at HERA is performed assuming the dominance of the "soft" pomeron exchange and simple, physically motivated parametrization of parton distributions in the pomeron. Both the LO and…
The HERA diffractive structure function data are interpreted in terms of `diffractive parton distributions' which satisfy DGLAP evolution. These distributions are modeled assuming that the scattering takes place off a colour singlet…
Crucial information on the coupling of the Higgs boson to bottom quarks is expected from Higgs production in association with a forward tagging jet at a future high-energy lepton-proton collider. In order to control the theoretical…
We perform a global parton fit to DIS and related data, including next-to-leading logarithmic (NLL) BFKL resummations in both the massless and massive sectors. The resummed fit improves over a standard next-to-leading order (NLO) DGLAP fit,…
We investigate the Q^2 evolution of parton distributions at small x values, obtained in the case of flat initial conditions. The results are in excellent agreement with deep inelastic scattering experimental data from HERA.
In the HERAPDF2.0 PDF analysis it was noted that the fit $\chi^2$ worsens significantly at low $Q^2$ for both NLO and NNLO fits. The turn over of the reduced cross section at low-$x$ and low $Q^2$ due to the contribution of the longitudinal…
Perturbative QCD predicts that at sufficiently large $Q^2$ and small $x$ nucleon structure functions should exhibit scaling in the two variables $\sqrt{\ln\smallfrac{1}{x}\ln\ln Q^2}$ and $\sqrt{\ln\smallfrac{1}{x}\big/\ln\ln Q^2}$,…
The recently reported excess of events at HERA compared to QCD calculations impels us to examine all possible Standard Model explanations before invoking ``new physics''. We explore the possibility of adding an unusual, but small, component…
A new NLO DGLAP QCD fit to recent inclusive diffractive DIS data from the H1 collaboration is presented. Diffractive parton distributions are extracted, including their experimental and theoretical uncertainties. The parton distributions…
After reviewing QCD definitions of the chiral-odd spin-dependent parton distributions $h_1(x,Q^2)$ and h_L(x,Q^2), I will summarize the main feature of the recent two results in perturbative QCD: (i) Next-to-leading order $Q^2$ evolution of…
We show that the diffractive structure function is perturbatively calculable in the domain where the diffractive mass is small but still outside the resonance region. In this domain, which can be characterized by Lambda^2/Q^2 << 1-beta <<…
We critically review the QCD predictions for the cross sections sigma_L and sigma_T for diffractive rho meson electroproduction in longitudinally and transversely polarised states in the HERA energy region. We show that both perturbative…
We have computed the complete next-to-next-to-leading order (NNLO) contributions to the splitting functions governing the evolution of unpolarized parton densities in perturbative QCD. Our results agree with all partial results available in…
We present estimates of possible data on spin-dependent asymmetries in inclusive scattering of high energy polarized electrons by high energy polarized protons at HERA with their statistical errors and discuss systematic errors. We show…
The next-to-next-to-leading order (NNLO) corrections in massless perturbative QCD are derived for the parton distributions of the photon and the deep inelastic structure functions F_1^gamma and F_2^gamma. We present the full photonic…
We analyse LEP and PETRA data on single inclusive charged hadron cross-sections to establish new sets of Next-to-Leading order Fragmentation Functions. Data on hadro-production of large-$p_{\bot}$ hadrons are also used to constrain the…
We study the effects of next-to-leading order corrections on the evolution of the twist-two non-forward parton distribution functions in the flavour non-singlet sector. It is found that the deviation from leading order evolution is small…
A QCD fit analysis to the combined HERA-I inclusive deep inelastic cross sections measured by the H1 and ZEUS collaborations for $e^\pm p$ scattering resulting into a competitive NLO PDF set, HERAPDF1.0 is presented. HERAPDF at NNLO fits…