Related papers: Forward Pi0-Meson Production at HERA
We present results from recent investigations of diffractive vector meson production using the ZEUS detector at HERA. These consist of measurements of rho production in the region of photon virtuality 0.25 < Q^2 < 0.85 GeV^2, of rho, phi,…
The dissociation of virtual photons, $\gamma^{\star} p \to X p$, in events with a large rapidity gap between $X$ and the outgoing proton, as well as in events in which the leading proton was directly measured, has been studied with the ZEUS…
The electroproduction of J/psi and psi(2S) mesons is studied in elastic, quasi-elastic and inclusive reactions for four momentum transfers 2 < Q^2 < 80 GeV^2 and photon-proton centre of mass energies 25 < W < 180 GeV. The data were taken…
The cross section for high-E_T dijet production in photoproduction has been measured with the ZEUS detector at HERA using an integrated luminosity of 81.8 pb-1. The events were required to have a virtuality of the incoming photon, Q^2, of…
We discuss recent preliminary results on the diffractive photoproduction of {\rhoz}, $\phi$, and {\jpsi} mesons at high momentum transfer reported by the ZEUS collaboration at HERA. A special-purpose calorimeter served to tag the quasi-real…
Inclusive photoproduction of D*+- mesons has been measured for photon-proton centre-of-mass energies in the range 130 < W < 280 GeV and a photon virtuality Q^2 < 1 GeV^2. The data sample used corresponds to an integrated luminosity of 37…
Elastic $\rho^0$ photoproduction has been measured using the ZEUS detector at HERA. Untagged photoproduction events from $ep$ interactions were used to measure the reaction $\gamma p \rightarrow \rho^0 p$ ($\rho^0 \rightarrow \pi^+ \pi^-$)…
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 first measurement of diffractive scattering of quasi-real photons with large momentum transfer is made using the H1 detector at HERA. Single differential cross sections are measured as a function of W, the incident photon-proton centre…
Multi-electron and multi-muon production have been measured at high transverse momentum in electron-proton collisions at HERA.Good overall agreement is found with the Standard Model predictions, dominated by photon-photon interactions.…
The inclusive e^-p single and double differential cross sections for neutral and charged current processes are measured with the H1 detector at HERA, in the range of four-momentum transfer squared Q^2 between 150 and 30000 GeV^2, and…
Data are presented on the production of jets and pi^0 mesons at low Bjorken x in a kinematic region where standard DGLAP evolution in Q^2 gives little phase space for high p_t particle and jet production. The data are compared with various…
The inclusive e^+ p single and double differential cross sections for neutral and charged current processes are measured with the H1 detector at HERA. The data were taken in 1999 and 2000 at a centre-of-mass energy of \sqrt{s} = 319 GeV and…
Recent results from the ep (electron-proton) collider HERA are presented. Jet production and diffraction type reactions allow tests of predictions of Quantum Chromodynamics (QCD). Jet measurements are used to improve the combined H1-ZEUS…
New results from the H1 and ZEUS collaborations on the measurement of cross-sections at very high Q^2 (up to 25000 GeV^2) and on the proton structure function F_2(x,Q^2) for momentum transfers squared Q^2 >= 1.5 GeV^2 and Bjorken x >= 3.5…
The photoproduction of isolated photons has been measured in diffractive events recorded by the ZEUS detector at HERA. Cross sections are evaluated in the photon transverse-energy and pseudorapidity ranges $5 < E_T < 15$ GeV and $-0.7 <…
The cross section for dijet photoproduction at high transverse energies is presented as a function of the transverse energies and the pseudorapidities of the jets. The measurement is performed using a sample of ep-interactions corresponding…
A measurement of the beauty production cross section in ep collisions at a centre-of-mass energy of 319 GeV is presented. The data were collected with the H1 detector at the HERA collider in the years 1999-2000. Events are selected by…
Prompt photons, together with an accompanying jet, have been studied in the photoproduction regime of ep scattering with the ZEUS detector at HERA. Predictions based on leading-logarithm parton-shower Monte Carlo models and…
Due to its unique pseudorapidity coverage and the ability to perform measurements at low transverse momenta, the LHCb detector allows a unique insight into particle production in the forward region at the LHC. Using large samples of…