Related papers: Diffractive Interactions in ep Collisions
The production of charm and beauty quarks in ep collisions at HERA has been studied by the H1 and ZEUS collaborations. Charm production is generally well described in total rate and in shape by next to leading order (NLO) calculations in…
Recent results on diffraction at HERA, as measured by the H1 and ZEUS collaborations, are reviewed. Results on the photon-proton total hadronic cross section, on vector meson production both at small and large photon virtuality and on…
Inclusive jet and multijet cross sections measured in ep collisions in different kinematic regions by the H1 and ZEUS experiments are shown. The measurements are used to extract the strong coupling alpha_s as a function of the scale and at…
We have calculated the diffractive dijet cross section in low-Q^2 ep scattering in the HERA regime. The results of the calculation in LO and NLO are compared to recent experimental data of the H1 collaboration. We find that in LO the…
We examine the role played in double parton interactions (DPI) by the parton--parton correlations originating from perturbative QCD parton splittings. Also presented are the results of the numerical analysis of the integrated DPI cross…
We have calculated the diffractive dijet cross section in low-Q^2 ep scattering in the HERA regime. The results of the calculation in LO and NLO are compared to recent experimental data of the H1 collaboration. We find that in LO the…
Photon diffractive dissociation, $\gamma p \to Xp$, has been studied at HERA with the ZEUS detector using $ep$ interactions where the virtuality $Q^2$ of the exchanged photon is smaller than 0.02 GeV$^2$. The squared four-momentum $t$…
The description of the QCD dynamics in the kinematical range which will be probed in the future electron - hadron colliders is still an open question. Although phenomenological studies indicate that the gluon number fluctuations, which are…
A recent H1 measurement of triple differential dijet cross sections in electron-proton interactions in the region of photon virtualities 2<Q2<80 GeV is presented and compared to LO and NLO QCD predictions. Effects that go beyond the…
The DGLAP and CCFM approaches to perturbative QCD evolution have been investigated by examining correlations of charmed hadron pairs in $pp$ collisions at $\sqrt{s}=7$ TeV. The theoretical models are compared to the data taken by the LHCb…
Results from the H1 and ZEUS experiments at HERA on deep inelastic scattering are reviewed. The data lead to a consistent picture of a steep rise in the F_2 structure function and in the gluon density within the proton. Important new…
New QCD results obtained by the H1 Collaboration are summarized. These results are based on data taken in $e^{\pm}p$ collisions at HERA I (1994-2002) and HERA II (2003-2007) corresponding to an integrated luminosity of almost $\rm 0.5…
The cross section for the diffractive deep-inelastic scattering process $ep \to e X p$ is measured, with the leading final state proton detected in the H1 Forward Proton Spectrometer. The data analysed cover the range \xpom <0.1 in…
With the knowledge of diffractive parton densities extracted from HERA data, we discuss the observation of exclusive events using the dijet mass fraction as measured by the CDF collaboration at the Tevatron. In particular the impact of the…
Close to one half of the LHC events are expected to be due to elastic or inelastic diffractive scattering. Still, predictions based on extrapolations of experimental data at lower energies differ by large factors in estimating the relative…
Models based on soft colour exchanges to rearrange colour strings in the final state provide a general framework for both diffractive and non-diffractive events in ep and hadron-hadron collisions. We study two such models and find that they…
New preliminary electroweak results from the HERA lepton-proton collider experiments H1 and ZEUS are presented. These include new high Q^2 neutral current cross section measurements and limits on a possible quark radius, in the search for…
A combination is presented of all inclusive deep inelastic cross sections previously published by the H1 and ZEUS collaborations at HERA for neutral and charged current $e^{\pm}p$ scattering for zero beam polarisation. The data were taken…
Using the QCD dipole picture of the hard BFKL pomeron, we derive the general expressions of the elastic and inelastic components of the proton diffractive structure functions. We obtain a good 7 parameter fit (including a secondary reggeon…
New results on charm and beauty electroproduction from the H1 and ZEUS Collaborations at the ep collider HERA are presented. Differential cross sections are compared to a next-to-leading order QCD calculation. The heavy quark contributions,…