Related papers: A Search for Instantons at HERA
Deep inelastic electron proton scattering at HERA II will allow precise studies of QCD and stringent tests of physics beyond the standard model. We discuss these two aspects of DIS with emphasis on the regime of high gluon densities at…
The contribution of the nonperturbative quark-gluon interaction induced by the instantons to $g_1^p(x,Q^2)$ and $F_2^p(x,Q^2)$ structure functions is estimated. It is shown that nontrivial $Q^2$ dependence of the instanton contribution to…
The Breit frame provides a natural frame to analyze lepton-proton scattering events. In this reference frame, the parton model hard interactions between a quark and an exchanged boson defines the coordinate system such that the struck quark…
The production of neutral strange hadrons is investigated using deep-inelastic scattering events measured with the H1 detector at HERA. The measurements are made in the phase space defined by the negative four-momentum transfer squared of…
A search for events with a high energy isolated electron or muon and missing transverse momentum has been performed at the electron-proton collider HERA using an integrated luminosity of 13.6 pb-1 in e-p scattering and 104.7 pb-1 in e+p…
Measurements are presented of differential dijet cross sections in diffractive photoproduction (Q^2<0.01 GeV^2) and deep-inelastic scattering processes (DIS, 4<Q^2<80 GeV^2). The event topology is given by ep-> e X Y, in which the system X,…
A search for events containing isolated tau leptons and large missing transverse momentum, not originating from the tau decay, has been performed with the ZEUS detector at the electron-proton collider HERA, using 130 pb^-1 of integrated…
A precision measurement of jet cross sections in neutral current deep-inelastic scattering for photon virtualities $5.5<Q^2<80\,{\rm GeV}^2$ and inelasticities $0.2<y<0.6$ is presented, using data taken with the H1 detector at HERA,…
Inclusive D* production is measured in deep-inelastic ep scattering at HERA with the H1 detector. In addition, the production of dijets in events with a D* meson is investigated. The analysis covers values of photon virtuality 2< Q^2 <=100…
Jet event rates in deep inelastic ep scattering at HERA are investigated applying the modified JADE jet algorithm. The analysis uses data taken with the H1 detector in 1994 and 1995. The data are corrected for detector and hadronization…
A search for events with an imbalance in transverse momentum and with isolated high energy leptons has been carried out at the positron-proton collider HERA. One event with an e^- and five events with a mu^+- are found together with…
We present a QCD-based model where rescattering between final state partons in deep inelastic scattering leads to events with large rapidity gaps and a leading proton. In the framework of this model the amplitude for multiple gluon…
The search for events containing isolated leptons (electrons or muons) and missing transverse momentum produced in e^{\pm}p collisions is performed individually and in a common phase space with the H1 and ZEUS detectors at HERA in the…
Recent measurements of inclusive deep inelastic scattering differential cross-section in the range 1.5 \gev2\le Q^2\le 30000 \gev2 and 5\cdot 10^{-6}\le x\le 0.65 are presented. Phenomenological analyses performed from these measurements…
A new measurement is presented of elastic deeply virtual Compton scattering (DVCS) based on data taken by the H1 detector during the complete HERA II period. The data are well described by QCD based calculations. For the first time, a beam…
A search for physics beyond the Standard Model in neutral current deep inelastic scattering at high negative four-momentum transfer squared Q^2 is performed in e^{\pm}p collisions at HERA. The differential cross section ds/dQ^2, measured…
Striking events with isolated charged leptons, large missing transverse momentum and large transverse momentum of the hadronic final state (PTX) have been observed at the electron proton collider HERA. In the full HERA-I data sample…
Measurements of $D^{*}(2010)$ meson production in diffractive deep inelastic scattering $(5<Q^{2}<100~{\rm GeV}^{2})$ are presented which are based on HERA data recorded at a centre-of-mass energy $\sqrt{s} = 319{\rm~GeV}$ with an…
Recent progress towards realizing the Electron-Ion Collider (EIC) that was announced in 2020 to be built at Brookhaven National Laboratory (BNL) in the United States has revived interests in the deep-inelastic-scattering (DIS) data taken…
The recently reported excess of events at HERA compared to QCD calculations impels us to examine all possible Standard Model explanations before invoking ``new physics''. We explore the possibility of adding an unusual, but small, component…