Related papers: Isolated Leptons and Single Top at HERA
Events containing a pair of charged leptons and significant missing transverse momentum are selected from a data sample corresponding to a total integrated luminosity of 20.6 pb^-1 at centre-of-mass energies of 161 GeV and 172 GeV. The…
A study of events containing two tau leptons with high transverse momentum has been performed with the ZEUS detector at HERA, using a data sample corresponding to an integrated luminosity of 0.33 fb-1. The tau candidates were identified…
A model-independent search for deviations from the Standard Model prediction has been performed in e+p and e-p collisions at HERA using H1 data. All experimentally measurable event topologies involving isolated electrons, photons, muons,…
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-proton transverse-energy and pseudorapidity ranges 5<ET(gamma)<15 GeV and…
A model-independent search for deviations from the Standard Model prediction is performed in e-p collisions at HERA II using H1 data recorded during the years 2005 and 2006, corresponding to an integrated luminosity of 159 inv.pb. All event…
The production of tau leptons in ep collisions is investigated using data recorded by the H1 detector at HERA in the period 1994-2000. Tau leptons are identified by detecting their decay products, using leptonic and hadronic decay modes.…
The H1 collaboration has recently reported the observation of events with an isolated high energy lepton and missing transverse momentum. All analysed Standard Model processes were found to fail in explaining the origin of muon events…
The production of isolated photons in deep-inelastic scattering $ep\to e \gamma X$ is measured with the H1 detector at HERA. The measurement is performed in the kinematic range of negative four-momentum transfer squared $4<Q^2<150 $~GeV$^2$…
A summary of the recent searches for anomalous single top-quark production and lepton flavour violation in high energy ep collisions is presented. Single top-quark production via an anomalous flavour changing neutral current gamma-u-t…
Speculations on mechanisms which might be responsible for events with an isolated high p_T lepton, a hadron jet and missing energy, as observed in the H1 experiment at HERA, are discussed.
The H1 and ZEUS collaborations have searched for signals of physics beyond the Standard Model in ep collisions at a center-of-mass energy of 301-319 GeV. During the HERA I phase each experiment accumulated an integrated luminosity of about…
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 $10 - 350$…
The H1 and ZEUS anomalous events are interpreted as being due to the production and the decay of excited leptons $E$, which correspond to spin 1/2 resonances of the first generation lepton doublet ($\nu_e, e$) with W triplet. This…
The graph of neutrinoless double beta decay is applied to HERA and generalized to final states with any two charged leptons. Considered is the case in which one of the two escapes typical identification criteria and the case when a produced…
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 <…
A search for excited electrons is performed using the full $e^{\pm}p$ data sample collected by the H1 experiment at HERA, corresponding to a total luminosity of 475 pb$^{-1}$. The electroweak decays of excited electrons…
Events with an isolated high $p_T$ lepton, a hadron jet and missing energy as observed in the H1 experiment at HERA, are potentially associated with R-parity violation in supersymmetric theories. However, stringent kinematic constraints…
Multi-electron production is studied at high electron transverse momentum in positron- and electron-proton collisions using the H1 detector at HERA. The data correspond to an integrated luminosity of 115 pb-1. Di-electron and tri-electron…
A search for excited neutrinos, the analysis of multi-lepton final states, a search for doubly charged Higgs production and a general search for high-Pt phenomena at HERA are reported. The searches use data samples of ep collisions with a…
The ZEUS detector at HERA has been used to measure the photoproduction of isolated photons in diffractive events. Cross sections are evaluated in the photon transverse-energy and pseudorapidity ranges 5 < E_T^gamma < 15 Gev and -0.7 <…