Related papers: Spectroscopy at HERA
A search for events with one or more isolated leptons in the final state is performed on a data sample collected in e+-p collisions with the H1 and ZEUS detectors at the HERA collider. The data sample corresponds to an integrated luminosity…
The exclusive deep inelastic electroproduction of $\psi(2S)$ and $J/\psi(1S)$ at an $ep$ centre-of-mass energy of 317 GeV has been studied with the ZEUS detector at HERA in the kinematic range $2 < Q^2 < 80$ GeV$^2$, $30 < W < 210$ GeV and…
A contact interaction analysis is presented to search for new phenomena beyond the Standard Model in deep inelastic $e^\pm p \rightarrow e^\pm \, hadrons$ scattering. The data are collected with the H1 detector at HERA and correspond to…
An extended study of exclusive vector meson production in e,p interactions has been performed by the H1 and the ZEUS collaborations at the HERA collider. Recent measurements are reported and discussed within the framework of the dipole…
A model-independent search for deviations from the Standard Model prediction is performed in e^+ p and e^- p collisions at HERA using H1 data corresponding to an integrated luminosity of 117 pb^-1. For the first time all event topologies…
Searches for excited electrons and neutrinos have been performed using the complete HERA I and II data samples collected by the H1 detector at $\sqrt{s}=320$ GeV corresponding to an integrated luminosity of up to 435 pb$^{-1}$. In absence…
The combination is presented of all inclusive deep inelastic scattering cross sections previously published by the H1 and ZEUS collaborations at HERA for neutral and charged current $ep$ scattering for zero beam polarisation. The data were…
HERA, the only ep collider, operated in the years 1992-2007 at centre-of-mass energies of 300-320 GeV in Hamburg, Germany. Deep inelastic neutral and charged current scattering at HERA provides the possibility to study the structure of the…
High-precision HERA data corresponding to a luminosity of around 1 fb$^{-1}$ have been used in the framework of $eeqq$ contact interactions (CI) to set limits on possible high-energy contributions beyond the Standard Model to electron-quark…
The study of photoproduction reactions has gained a unique opportunity with the HERA data. The high center of mass energy allows to carry out quantitative tests of QCD, to explore the substructure of both the photon and the proton and to…
The first observation of open b production in ep collisions is reported. An event sample containing muons and jets has been selected which is enriched in semileptonic b quark decays. The visible cross section \sigma(ep -> b \bar{b}X -> \mu…
A search for photoproduction events which contain a rapidity gap between the two highest transverse energy jets has been conducted at HERA using the ZEUS detector. The jets have transverse energies greater than 6~GeV, and are separated by…
The photon-proton total cross section has been measured in the process e+ p -> e+ gamma p -> e+ X with the ZEUS detector at HERA. Events were collected with photon virtuality Q^2 < 0.02 GeV^2 and average gamma-p center-of-mass energy…
The exclusive deep inelastic electroproduction of $\psi(2S)$ and $J/\psi(1S)$ at an $ep$ centre-of-mass energy of 317 GeV has been studied with the ZEUS detector at HERA in the kinematic range $2 < Q^2 < 80$ GeV$^2$, $30 < W < 210$ GeV and…
Neutral-current (NC) and charged-current (CC) deep inelastic scattering (DIS) interactions have been studied in electron-proton and positron-proton collisions with longitudinally polarised lepton beams using the H1 and ZEUS detectors at…
The first measurement of D*+/- meson diffractive photoproduction cross sections has been performed with the ZEUS detector at the HERA $ep$ collider, using an integrated luminosity of 38 pb^-1. The measurement has been performed for…
Isolated photons with high transverse energy have been studied in deep inelastic $ep$ scattering with the ZEUS detector at HERA, using an integrated luminosity of $326\,$ pb$^{-1}$ in the range of exchanged-photon virtuality $10 - 350$…
A search for squarks in R-parity violating supersymmetry is performed in e^+p collisions at HERA at a centre of mass energy of 300 GeV, using H1 data corresponding to an integrated luminosity of 37 pb^(-1). The direct production of single…
A search for gravitinos produced in ep collisions is performed using the H1 detector at HERA. The data were taken at a centre-of-mass energy of 319 GeV and correspond to an integrated luminosity of 64.3 pb^{-1} for e^+p collisions and 13.5…
Recent results on light hadron spectroscopy are reported, with special emphasis on the evidence for a narrow baryonic state decaying to Ks p and Ks pbar, compatible with the pentaquark state theta^+ observed by fixed target experiments. The…