Related papers: Limits on contact interactions and leptoquarks at …
A search for first generation scalar and vector leptoquarks produced in ep collisions is performed by the H1 experiment at HERA. The full H1 data sample is used in the analysis, corresponding to an integrated luminosity of 446 pb^-1. No…
The excess of high-Q2 events recently observed in deep-inelastic positron-proton scattering at HERA has refuelled speculations on physics beyond the standard model, in particular on low-mass leptoquark-type particles. We review the…
A search for scalar and vector leptoquarks coupling to first generation fermions is performed using the e^+p and e^-p scattering data collected by the H1 experiment between 1994 and 2000. The data correspond to a total integrated luminosity…
The latest measurements of the cross sections for neutral and charged current deep inelastic scattering in e+/-p collisions at HERA with longitudinally polarised lepton beams are presented. The measured cross sections are compared with the…
A search for first generation scalar and vector leptoquarks produced in ep collisions is performed by the H1 Collaboration at HERA. The full H1 data sample is used in the analysis, corresponding to an integrated luminosity 446 pb^-1. No…
Virtual leptoquarks could be detected at HERA through some nonstandard effects. Here we explore the possibility that virtual leptoquarks could be discovered via $e u --> e c$ scattering, assuming integrated luminosity of 200 pb$^{-1}$ and…
Signals of physics beyond the Standard Model at HERA have been searched for by the H1 and ZEUS collaborations. Results are reported about searches of contact interaction effects, leptoquarks, R-parity violating squarks, excited fermions and…
A search for leptoquarks at HERA was performed in H1 using 1994 $e^+ p$ data corresponding to an integrated luminosity of about $3 \pb^{-1}$. Single leptoquarks were searched for in direct positron-quark fusion processes taking into account…
The excess of high-$Q^2$ events found by H1 and ZEUS at HERA in $e^+p$ deep-inelastic scattering above the Standard Model prediction motivates us to calculate the NLO QCD corrections to the HERA scalar leptoquark (or squark) production…
We update the global constraint on four-fermion $ee q q$ contact interactions. In this update, we included the published data of H1 and ZEUS for the 94--96 run in the $e^+ p$ mode and the newly published data of H1 for the 1999 run in the…
A search for lepton-flavor-violating interactions $e p \to \mu X $ and $e p\to \tau X $ has been performed with the ZEUS detector using the entire HERA I data sample, corresponding to an integrated luminosity of 130 pb^{-1}. The data were…
We explore interpretations of the anomaly observed by H1 and ZEUS at HERA in deep-inelastic e^+ p scattering at very large Q^2. We discuss the possibilities of new effective interactions and the production of a narrow state of mass 200 GeV…
Theoretical interpretations of the high-Q^2 events recently observed in deep-inelastic positron-proton scattering at HERA are reviewed. We discuss leptoquarks, squarks with R-parity violating couplings, and contact interactions. Bounds from…
The e^+ jet invariant mass spectrum produced in the reaction e^+ p -> e^+ X has been studied at a center-of-mass energy of 300 GeV. The data were collected using the ZEUS detector operating at the HERA collider, and correspond to an…
Neutral and charged current deep inelastic ep scattering with longitudinally polarised lepton beams has been studied with the H1 and ZEUS detectors at HERA. The differential cross sections were measured in the range of four-momentum…
This talk covers three contributions from H1: "Measurement of the inclusive e^\pm p scattering cross section at high inelasticity y and of the structure function F_L", "Determination of the integrated luminosity at HERA using elastic QED…
The prospect of an ep collider involving an LHC proton beam and a new electron accelerator is discussed. Configurations reaching centre of mass energies a factor of 5 beyond HERA are possible with luminosities of the order of 10^33 cm^-2…
A search for second and third generation scalar and vector leptoquarks produced in ep collisions via the lepton flavour violating processes ep -> mu X and ep -> tau X is performed by the H1 experiment at HERA. The full data sample taken at…
Searches for physics beyond the Standard Model have been performed in high-energy $e^{\pm}p$ collisions at HERA. No significant deviation from the Standard Model has been observed while searching for contact interactions, extra dimensions,…
A search for first-generation leptoquarks was performed in electron-proton and positron-proton collisions recorded with the ZEUS detector at HERA in 2003-2007 using an integrated luminosity of 366 pb^-1. Final states with an electron and…